Module aws_lambda_powertools.event_handler.api_gateway
Expand source code
import base64
import json
import logging
import re
import traceback
import warnings
import zlib
from abc import ABC, abstractmethod
from enum import Enum
from functools import partial
from http import HTTPStatus
from pathlib import Path
from typing import (
TYPE_CHECKING,
Any,
Callable,
Dict,
Generic,
List,
Match,
Optional,
Pattern,
Sequence,
Set,
Tuple,
Type,
TypeVar,
Union,
cast,
)
from aws_lambda_powertools.event_handler import content_types
from aws_lambda_powertools.event_handler.exceptions import NotFoundError, ServiceError
from aws_lambda_powertools.event_handler.openapi.constants import DEFAULT_API_VERSION, DEFAULT_OPENAPI_VERSION
from aws_lambda_powertools.event_handler.openapi.swagger_ui.html import generate_swagger_html
from aws_lambda_powertools.event_handler.openapi.types import (
COMPONENT_REF_PREFIX,
METHODS_WITH_BODY,
validation_error_definition,
validation_error_response_definition,
)
from aws_lambda_powertools.shared.cookies import Cookie
from aws_lambda_powertools.shared.functions import powertools_dev_is_set
from aws_lambda_powertools.shared.json_encoder import Encoder
from aws_lambda_powertools.shared.types import Literal
from aws_lambda_powertools.utilities.data_classes import (
ALBEvent,
APIGatewayProxyEvent,
APIGatewayProxyEventV2,
BedrockAgentEvent,
LambdaFunctionUrlEvent,
VPCLatticeEvent,
VPCLatticeEventV2,
)
from aws_lambda_powertools.utilities.data_classes.common import BaseProxyEvent
from aws_lambda_powertools.utilities.typing import LambdaContext
logger = logging.getLogger(__name__)
_DYNAMIC_ROUTE_PATTERN = r"(<\w+>)"
_SAFE_URI = "-._~()'!*:@,;=+&$" # https://www.ietf.org/rfc/rfc3986.txt
# API GW/ALB decode non-safe URI chars; we must support them too
_UNSAFE_URI = r"%<> \[\]{}|^"
_NAMED_GROUP_BOUNDARY_PATTERN = rf"(?P\1[{_SAFE_URI}{_UNSAFE_URI}\\w]+)"
_DEFAULT_OPENAPI_RESPONSE_DESCRIPTION = "Successful Response"
_ROUTE_REGEX = "^{}$"
ResponseEventT = TypeVar("ResponseEventT", bound=BaseProxyEvent)
if TYPE_CHECKING:
from aws_lambda_powertools.event_handler.openapi.compat import (
JsonSchemaValue,
ModelField,
)
from aws_lambda_powertools.event_handler.openapi.models import (
Contact,
License,
OpenAPI,
Server,
)
from aws_lambda_powertools.event_handler.openapi.params import Dependant
from aws_lambda_powertools.event_handler.openapi.types import (
TypeModelOrEnum,
)
class ProxyEventType(Enum):
"""An enumerations of the supported proxy event types."""
APIGatewayProxyEvent = "APIGatewayProxyEvent"
APIGatewayProxyEventV2 = "APIGatewayProxyEventV2"
ALBEvent = "ALBEvent"
BedrockAgentEvent = "BedrockAgentEvent"
VPCLatticeEvent = "VPCLatticeEvent"
VPCLatticeEventV2 = "VPCLatticeEventV2"
LambdaFunctionUrlEvent = "LambdaFunctionUrlEvent"
class CORSConfig:
"""CORS Config
Examples
--------
Simple cors example using the default permissive cors, not this should only be used during early prototyping
```python
from aws_lambda_powertools.event_handler import APIGatewayRestResolver
app = APIGatewayRestResolver()
@app.get("/my/path", cors=True)
def with_cors():
return {"message": "Foo"}
```
Using a custom CORSConfig where `with_cors` used the custom provided CORSConfig and `without_cors`
do not include any cors headers.
```python
from aws_lambda_powertools.event_handler.api_gateway import (
APIGatewayRestResolver, CORSConfig
)
cors_config = CORSConfig(
allow_origin="https://wwww.example.com/",
extra_origins=["https://dev.example.com/"],
expose_headers=["x-exposed-response-header"],
allow_headers=["x-custom-request-header"],
max_age=100,
allow_credentials=True,
)
app = APIGatewayRestResolver(cors=cors_config)
@app.get("/my/path")
def with_cors():
return {"message": "Foo"}
@app.get("/another-one", cors=False)
def without_cors():
return {"message": "Foo"}
```
"""
_REQUIRED_HEADERS = ["Authorization", "Content-Type", "X-Amz-Date", "X-Api-Key", "X-Amz-Security-Token"]
def __init__(
self,
allow_origin: str = "*",
extra_origins: Optional[List[str]] = None,
allow_headers: Optional[List[str]] = None,
expose_headers: Optional[List[str]] = None,
max_age: Optional[int] = None,
allow_credentials: bool = False,
):
"""
Parameters
----------
allow_origin: str
The value of the `Access-Control-Allow-Origin` to send in the response. Defaults to "*", but should
only be used during development.
extra_origins: Optional[List[str]]
The list of additional allowed origins.
allow_headers: Optional[List[str]]
The list of additional allowed headers. This list is added to list of
built-in allowed headers: `Authorization`, `Content-Type`, `X-Amz-Date`,
`X-Api-Key`, `X-Amz-Security-Token`.
expose_headers: Optional[List[str]]
A list of values to return for the Access-Control-Expose-Headers
max_age: Optional[int]
The value for the `Access-Control-Max-Age`
allow_credentials: bool
A boolean value that sets the value of `Access-Control-Allow-Credentials`
"""
self._allowed_origins = [allow_origin]
if extra_origins:
self._allowed_origins.extend(extra_origins)
self.allow_headers = set(self._REQUIRED_HEADERS + (allow_headers or []))
self.expose_headers = expose_headers or []
self.max_age = max_age
self.allow_credentials = allow_credentials
def to_dict(self, origin: Optional[str]) -> Dict[str, str]:
"""Builds the configured Access-Control http headers"""
# If there's no Origin, don't add any CORS headers
if not origin:
return {}
# If the origin doesn't match any of the allowed origins, and we don't allow all origins ("*"),
# don't add any CORS headers
if origin not in self._allowed_origins and "*" not in self._allowed_origins:
return {}
# The origin matched an allowed origin, so return the CORS headers
headers: Dict[str, str] = {
"Access-Control-Allow-Origin": origin,
"Access-Control-Allow-Headers": ",".join(sorted(self.allow_headers)),
}
if self.expose_headers:
headers["Access-Control-Expose-Headers"] = ",".join(self.expose_headers)
if self.max_age is not None:
headers["Access-Control-Max-Age"] = str(self.max_age)
if self.allow_credentials is True:
headers["Access-Control-Allow-Credentials"] = "true"
return headers
class Response:
"""Response data class that provides greater control over what is returned from the proxy event"""
def __init__(
self,
status_code: int,
content_type: Optional[str] = None,
body: Any = None,
headers: Optional[Dict[str, Union[str, List[str]]]] = None,
cookies: Optional[List[Cookie]] = None,
compress: Optional[bool] = None,
):
"""
Parameters
----------
status_code: int
Http status code, example 200
content_type: str
Optionally set the Content-Type header, example "application/json". Note this will be merged into any
provided http headers
body: Union[str, bytes, None]
Optionally set the response body. Note: bytes body will be automatically base64 encoded
headers: dict[str, Union[str, List[str]]]
Optionally set specific http headers. Setting "Content-Type" here would override the `content_type` value.
cookies: list[Cookie]
Optionally set cookies.
"""
self.status_code = status_code
self.body = body
self.base64_encoded = False
self.headers: Dict[str, Union[str, List[str]]] = headers if headers else {}
self.cookies = cookies or []
self.compress = compress
self.content_type = content_type
if content_type:
self.headers.setdefault("Content-Type", content_type)
def is_json(self) -> bool:
"""
Returns True if the response is JSON, based on the Content-Type.
"""
content_type = self.headers.get("Content-Type", "")
if isinstance(content_type, list):
content_type = content_type[0]
return content_type.startswith("application/json")
class Route:
"""Internally used Route Configuration"""
def __init__(
self,
method: str,
path: str,
rule: Pattern,
func: Callable,
cors: bool,
compress: bool,
cache_control: Optional[str],
summary: Optional[str],
description: Optional[str],
responses: Optional[Dict[int, Dict[str, Any]]],
response_description: Optional[str],
tags: Optional[List[str]],
operation_id: Optional[str],
include_in_schema: bool,
middlewares: Optional[List[Callable[..., Response]]],
):
"""
Parameters
----------
method: str
The HTTP method, example "GET"
path: str
The path of the route
rule: Pattern
The route rule, example "/my/path"
func: Callable
The route handler function
cors: bool
Whether or not to enable CORS for this route
compress: bool
Whether or not to enable gzip compression for this route
cache_control: Optional[str]
The cache control header value, example "max-age=3600"
summary: Optional[str]
The OpenAPI summary for this route
description: Optional[str]
The OpenAPI description for this route
responses: Optional[Dict[int, Dict[str, Any]]]
The OpenAPI responses for this route
response_description: Optional[str]
The OpenAPI response description for this route
tags: Optional[List[str]]
The list of OpenAPI tags to be used for this route
operation_id: Optional[str]
The OpenAPI operationId for this route
include_in_schema: bool
Whether or not to include this route in the OpenAPI schema
middlewares: Optional[List[Callable[..., Response]]]
The list of route middlewares to be called in order.
"""
self.method = method.upper()
self.path = "/" if path.strip() == "" else path
self.rule = rule
self.func = func
self._middleware_stack = func
self.cors = cors
self.compress = compress
self.cache_control = cache_control
self.summary = summary
self.description = description
self.responses = responses
self.response_description = response_description
self.tags = tags or []
self.include_in_schema = include_in_schema
self.middlewares = middlewares or []
self.operation_id = operation_id or self._generate_operation_id()
# _middleware_stack_built is used to ensure the middleware stack is only built once.
self._middleware_stack_built = False
# _dependant is used to cache the dependant model for the handler function
self._dependant: Optional["Dependant"] = None
# _body_field is used to cache the dependant model for the body field
self._body_field: Optional["ModelField"] = None
def __call__(
self,
router_middlewares: List[Callable],
app: "ApiGatewayResolver",
route_arguments: Dict[str, str],
) -> Union[Dict, Tuple, Response]:
"""Calling the Router class instance will trigger the following actions:
1. If Route Middleware stack has not been built, build it
2. Call the Route Middleware stack wrapping the original function
handler with the app and route arguments.
Parameters
----------
router_middlewares: List[Callable]
The list of Router Middlewares (assigned to ALL routes)
app: "ApiGatewayResolver"
The ApiGatewayResolver instance to pass into the middleware stack
route_arguments: Dict[str, str]
The route arguments to pass to the app function (extracted from the Api Gateway
Lambda Message structure from AWS)
Returns
-------
Union[Dict, Tuple, Response]
API Response object in ALL cases, except when the original API route
handler is called which may also return a Dict, Tuple, or Response.
"""
# Save CPU cycles by building middleware stack once
if not self._middleware_stack_built:
self._build_middleware_stack(router_middlewares=router_middlewares)
# If debug is turned on then output the middleware stack to the console
if app._debug:
print(f"\nProcessing Route:::{self.func.__name__} ({app.context['_path']})")
# Collect ALL middleware for debug printing - include internal _registered_api_adapter
all_middlewares = router_middlewares + self.middlewares + [_registered_api_adapter]
print("\nMiddleware Stack:")
print("=================")
print("\n".join(getattr(item, "__name__", "Unknown") for item in all_middlewares))
print("=================")
# Add Route Arguments to app context
app.append_context(_route_args=route_arguments)
# Call the Middleware Wrapped _call_stack function handler with the app
return self._middleware_stack(app)
def _build_middleware_stack(self, router_middlewares: List[Callable[..., Any]]) -> None:
"""
Builds the middleware stack for the handler by wrapping each
handler in an instance of MiddlewareWrapper which is used to contain the state
of each middleware step.
Middleware is represented by a standard Python Callable construct. Any Middleware
handler wanting to short-circuit the middlware call chain can raise an exception
to force the Python call stack created by the handler call-chain to naturally un-wind.
This becomes a simple concept for developers to understand and reason with - no additional
gymanstics other than plain old try ... except.
Notes
-----
The Route Middleware stack is processed in reverse order. This is so the stack of
middleware handlers is applied in the order of being added to the handler.
"""
all_middlewares = router_middlewares + self.middlewares
logger.debug(f"Building middleware stack: {all_middlewares}")
# IMPORTANT:
# this must be the last middleware in the stack (tech debt for backward
# compatibility purposes)
#
# This adapter will:
# 1. Call the registered API passing only the expected route arguments extracted from the path
# and not the middleware.
# 2. Adapt the response type of the route handler (Union[Dict, Tuple, Response])
# and normalise into a Response object so middleware will always have a constant signature
all_middlewares.append(_registered_api_adapter)
# Wrap the original route handler function in the middleware handlers
# using the MiddlewareWrapper class callable construct in reverse order to
# ensure middleware is applied in the order the user defined.
#
# Start with the route function and wrap from last to the first Middleware handler.
for handler in reversed(all_middlewares):
self._middleware_stack = MiddlewareFrame(current_middleware=handler, next_middleware=self._middleware_stack)
self._middleware_stack_built = True
@property
def dependant(self) -> "Dependant":
if self._dependant is None:
from aws_lambda_powertools.event_handler.openapi.dependant import get_dependant
self._dependant = get_dependant(path=self.path, call=self.func)
return self._dependant
@property
def body_field(self) -> Optional["ModelField"]:
if self._body_field is None:
from aws_lambda_powertools.event_handler.openapi.dependant import get_body_field
self._body_field = get_body_field(dependant=self.dependant, name=self.operation_id)
return self._body_field
def _get_openapi_path(
self,
*,
dependant: "Dependant",
operation_ids: Set[str],
model_name_map: Dict["TypeModelOrEnum", str],
field_mapping: Dict[Tuple["ModelField", Literal["validation", "serialization"]], "JsonSchemaValue"],
) -> Tuple[Dict[str, Any], Dict[str, Any]]:
"""
Returns the OpenAPI path and definitions for the route.
"""
from aws_lambda_powertools.event_handler.openapi.dependant import get_flat_params
path = {}
definitions: Dict[str, Any] = {}
# Gather all the route parameters
operation = self._openapi_operation_metadata(operation_ids=operation_ids)
parameters: List[Dict[str, Any]] = []
all_route_params = get_flat_params(dependant)
operation_params = self._openapi_operation_parameters(
all_route_params=all_route_params,
model_name_map=model_name_map,
field_mapping=field_mapping,
)
parameters.extend(operation_params)
# Add the parameters to the OpenAPI operation
if parameters:
all_parameters = {(param["in"], param["name"]): param for param in parameters}
required_parameters = {(param["in"], param["name"]): param for param in parameters if param.get("required")}
all_parameters.update(required_parameters)
operation["parameters"] = list(all_parameters.values())
# Add the request body to the OpenAPI operation, if applicable
if self.method.upper() in METHODS_WITH_BODY:
request_body_oai = self._openapi_operation_request_body(
body_field=self.body_field,
model_name_map=model_name_map,
field_mapping=field_mapping,
)
if request_body_oai:
operation["requestBody"] = request_body_oai
# Add the response to the OpenAPI operation
if self.responses:
# If the user supplied responses, we use them and don't set a default 200 response
operation["responses"] = self.responses
else:
# Set the default 200 response
responses = operation.setdefault("responses", self.responses or {})
success_response = responses.setdefault(200, {})
success_response["description"] = self.response_description or _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION
success_response["content"] = {"application/json": {"schema": {}}}
json_response = success_response["content"].setdefault("application/json", {})
# Add the response schema to the OpenAPI 200 response
json_response.update(
self._openapi_operation_return(
param=dependant.return_param,
model_name_map=model_name_map,
field_mapping=field_mapping,
),
)
# Add validation failure response (422)
operation["responses"][422] = {
"description": "Validation Error",
"content": {
"application/json": {
"schema": {"$ref": COMPONENT_REF_PREFIX + "HTTPValidationError"},
},
},
}
# Add the validation error schema to the definitions, but only if it hasn't been added yet
if "ValidationError" not in definitions:
definitions.update(
{
"ValidationError": validation_error_definition,
"HTTPValidationError": validation_error_response_definition,
},
)
path[self.method.lower()] = operation
# Generate the response schema
return path, definitions
def _openapi_operation_summary(self) -> str:
"""
Returns the OpenAPI operation summary. If the user has not provided a summary, we
generate one based on the route path and method.
"""
return self.summary or f"{self.method.upper()} {self.path}"
def _openapi_operation_metadata(self, operation_ids: Set[str]) -> Dict[str, Any]:
"""
Returns the OpenAPI operation metadata. If the user has not provided a description, we
generate one based on the route path and method.
"""
operation: Dict[str, Any] = {}
# Ensure tags is added to the operation
if self.tags:
operation["tags"] = [{"name": tag for tag in self.tags}]
# Ensure summary is added to the operation
operation["summary"] = self._openapi_operation_summary()
# Ensure description is added to the operation
if self.description:
operation["description"] = self.description
# Ensure operationId is unique
if self.operation_id in operation_ids:
message = f"Duplicate Operation ID {self.operation_id} for function {self.func.__name__}"
file_name = getattr(self.func, "__globals__", {}).get("__file__")
if file_name:
message += f" in {file_name}"
warnings.warn(message, stacklevel=1)
# Adds the operation
operation_ids.add(self.operation_id)
operation["operationId"] = self.operation_id
return operation
@staticmethod
def _openapi_operation_request_body(
*,
body_field: Optional["ModelField"],
model_name_map: Dict["TypeModelOrEnum", str],
field_mapping: Dict[Tuple["ModelField", Literal["validation", "serialization"]], "JsonSchemaValue"],
) -> Optional[Dict[str, Any]]:
"""
Returns the OpenAPI operation request body.
"""
from aws_lambda_powertools.event_handler.openapi.compat import ModelField, get_schema_from_model_field
from aws_lambda_powertools.event_handler.openapi.params import Body
# Check that there is a body field and it's a Pydantic's model field
if not body_field:
return None
if not isinstance(body_field, ModelField):
raise AssertionError(f"Expected ModelField, got {body_field}")
# Generate the request body schema
body_schema = get_schema_from_model_field(
field=body_field,
model_name_map=model_name_map,
field_mapping=field_mapping,
)
field_info = cast(Body, body_field.field_info)
request_media_type = field_info.media_type
required = body_field.required
request_body_oai: Dict[str, Any] = {}
if required:
request_body_oai["required"] = required
# Generate the request body media type
request_media_content: Dict[str, Any] = {"schema": body_schema}
request_body_oai["content"] = {request_media_type: request_media_content}
return request_body_oai
@staticmethod
def _openapi_operation_parameters(
*,
all_route_params: Sequence["ModelField"],
model_name_map: Dict["TypeModelOrEnum", str],
field_mapping: Dict[
Tuple["ModelField", Literal["validation", "serialization"]],
"JsonSchemaValue",
],
) -> List[Dict[str, Any]]:
"""
Returns the OpenAPI operation parameters.
"""
from aws_lambda_powertools.event_handler.openapi.compat import (
get_schema_from_model_field,
)
from aws_lambda_powertools.event_handler.openapi.params import Param
parameters = []
for param in all_route_params:
field_info = param.field_info
field_info = cast(Param, field_info)
if not field_info.include_in_schema:
continue
param_schema = get_schema_from_model_field(
field=param,
model_name_map=model_name_map,
field_mapping=field_mapping,
)
parameter = {
"name": param.alias,
"in": field_info.in_.value,
"required": param.required,
"schema": param_schema,
}
if field_info.description:
parameter["description"] = field_info.description
if field_info.deprecated:
parameter["deprecated"] = field_info.deprecated
parameters.append(parameter)
return parameters
@staticmethod
def _openapi_operation_return(
*,
param: Optional["ModelField"],
model_name_map: Dict["TypeModelOrEnum", str],
field_mapping: Dict[
Tuple["ModelField", Literal["validation", "serialization"]],
"JsonSchemaValue",
],
) -> Dict[str, Any]:
"""
Returns the OpenAPI operation return.
"""
if param is None:
return {}
from aws_lambda_powertools.event_handler.openapi.compat import (
get_schema_from_model_field,
)
return_schema = get_schema_from_model_field(
field=param,
model_name_map=model_name_map,
field_mapping=field_mapping,
)
return {"schema": return_schema}
def _generate_operation_id(self) -> str:
operation_id = self.func.__name__ + self.path
operation_id = re.sub(r"\W", "_", operation_id)
operation_id = operation_id + "_" + self.method.lower()
return operation_id
class ResponseBuilder(Generic[ResponseEventT]):
"""Internally used Response builder"""
def __init__(self, response: Response, route: Optional[Route] = None):
self.response = response
self.route = route
def _add_cors(self, event: ResponseEventT, cors: CORSConfig):
"""Update headers to include the configured Access-Control headers"""
self.response.headers.update(cors.to_dict(event.get_header_value("Origin")))
def _add_cache_control(self, cache_control: str):
"""Set the specified cache control headers for 200 http responses. For non-200 `no-cache` is used."""
cache_control = cache_control if self.response.status_code == 200 else "no-cache"
self.response.headers["Cache-Control"] = cache_control
@staticmethod
def _has_compression_enabled(
route_compression: bool,
response_compression: Optional[bool],
event: ResponseEventT,
) -> bool:
"""
Checks if compression is enabled.
NOTE: Response compression takes precedence.
Parameters
----------
route_compression: bool, optional
A boolean indicating whether compression is enabled or not in the route setting.
response_compression: bool, optional
A boolean indicating whether compression is enabled or not in the response setting.
event: ResponseEventT
The event object containing the request details.
Returns
-------
bool
True if compression is enabled and the "gzip" encoding is accepted, False otherwise.
"""
encoding: str = event.get_header_value(
name="accept-encoding",
default_value="",
case_sensitive=False,
) # noqa: E501
if "gzip" in encoding:
if response_compression is not None:
return response_compression # e.g., Response(compress=False/True))
if route_compression:
return True # e.g., @app.get(compress=True)
return False
def _compress(self):
"""Compress the response body, but only if `Accept-Encoding` headers includes gzip."""
self.response.headers["Content-Encoding"] = "gzip"
if isinstance(self.response.body, str):
logger.debug("Converting string response to bytes before compressing it")
self.response.body = bytes(self.response.body, "utf-8")
gzip = zlib.compressobj(9, zlib.DEFLATED, zlib.MAX_WBITS | 16)
self.response.body = gzip.compress(self.response.body) + gzip.flush()
def _route(self, event: ResponseEventT, cors: Optional[CORSConfig]):
"""Optionally handle any of the route's configure response handling"""
if self.route is None:
return
if self.route.cors:
self._add_cors(event, cors or CORSConfig())
if self.route.cache_control:
self._add_cache_control(self.route.cache_control)
if self._has_compression_enabled(
route_compression=self.route.compress,
response_compression=self.response.compress,
event=event,
):
self._compress()
def build(self, event: ResponseEventT, cors: Optional[CORSConfig] = None) -> Dict[str, Any]:
"""Build the full response dict to be returned by the lambda"""
self._route(event, cors)
if isinstance(self.response.body, bytes):
logger.debug("Encoding bytes response with base64")
self.response.base64_encoded = True
self.response.body = base64.b64encode(self.response.body).decode()
return {
"statusCode": self.response.status_code,
"body": self.response.body,
"isBase64Encoded": self.response.base64_encoded,
**event.header_serializer().serialize(headers=self.response.headers, cookies=self.response.cookies),
}
class BaseRouter(ABC):
current_event: BaseProxyEvent
lambda_context: LambdaContext
context: dict
_router_middlewares: List[Callable] = []
processed_stack_frames: List[str] = []
@abstractmethod
def route(
self,
rule: str,
method: Any,
cors: Optional[bool] = None,
compress: bool = False,
cache_control: Optional[str] = None,
summary: Optional[str] = None,
description: Optional[str] = None,
responses: Optional[Dict[int, Dict[str, Any]]] = None,
response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION,
tags: Optional[List[str]] = None,
operation_id: Optional[str] = None,
include_in_schema: bool = True,
middlewares: Optional[List[Callable[..., Any]]] = None,
):
raise NotImplementedError()
def use(self, middlewares: List[Callable[..., Response]]) -> None:
"""
Add one or more global middlewares that run before/after route specific middleware.
NOTE: Middlewares are called in insertion order.
Parameters
----------
middlewares: List[Callable[..., Response]]
List of global middlewares to be used
Examples
--------
Add middlewares to be used for every request processed by the Router.
```python
from aws_lambda_powertools import Logger
from aws_lambda_powertools.event_handler import APIGatewayRestResolver, Response
from aws_lambda_powertools.event_handler.middlewares import NextMiddleware
logger = Logger()
app = APIGatewayRestResolver()
def log_request_response(app: APIGatewayRestResolver, next_middleware: NextMiddleware) -> Response:
logger.info("Incoming request", path=app.current_event.path, request=app.current_event.raw_event)
result = next_middleware(app)
logger.info("Response received", response=result.__dict__)
return result
app.use(middlewares=[log_request_response])
def lambda_handler(event, context):
return app.resolve(event, context)
```
"""
self._router_middlewares = self._router_middlewares + middlewares
def get(
self,
rule: str,
cors: Optional[bool] = None,
compress: bool = False,
cache_control: Optional[str] = None,
summary: Optional[str] = None,
description: Optional[str] = None,
responses: Optional[Dict[int, Dict[str, Any]]] = None,
response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION,
tags: Optional[List[str]] = None,
operation_id: Optional[str] = None,
include_in_schema: bool = True,
middlewares: Optional[List[Callable[..., Any]]] = None,
):
"""Get route decorator with GET `method`
Examples
--------
Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator
```python
from aws_lambda_powertools import Tracer
from aws_lambda_powertools.event_handler import APIGatewayRestResolver
tracer = Tracer()
app = APIGatewayRestResolver()
@app.get("/get-call")
def simple_get():
return {"message": "Foo"}
@tracer.capture_lambda_handler
def lambda_handler(event, context):
return app.resolve(event, context)
```
"""
return self.route(
rule,
"GET",
cors,
compress,
cache_control,
summary,
description,
responses,
response_description,
tags,
operation_id,
include_in_schema,
middlewares,
)
def post(
self,
rule: str,
cors: Optional[bool] = None,
compress: bool = False,
cache_control: Optional[str] = None,
summary: Optional[str] = None,
description: Optional[str] = None,
responses: Optional[Dict[int, Dict[str, Any]]] = None,
response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION,
tags: Optional[List[str]] = None,
operation_id: Optional[str] = None,
include_in_schema: bool = True,
middlewares: Optional[List[Callable[..., Any]]] = None,
):
"""Post route decorator with POST `method`
Examples
--------
Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator
```python
from aws_lambda_powertools import Tracer
from aws_lambda_powertools.event_handler import APIGatewayRestResolver
tracer = Tracer()
app = APIGatewayRestResolver()
@app.post("/post-call")
def simple_post():
post_data: dict = app.current_event.json_body
return {"message": post_data["value"]}
@tracer.capture_lambda_handler
def lambda_handler(event, context):
return app.resolve(event, context)
```
"""
return self.route(
rule,
"POST",
cors,
compress,
cache_control,
summary,
description,
responses,
response_description,
tags,
operation_id,
include_in_schema,
middlewares,
)
def put(
self,
rule: str,
cors: Optional[bool] = None,
compress: bool = False,
cache_control: Optional[str] = None,
summary: Optional[str] = None,
description: Optional[str] = None,
responses: Optional[Dict[int, Dict[str, Any]]] = None,
response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION,
tags: Optional[List[str]] = None,
operation_id: Optional[str] = None,
include_in_schema: bool = True,
middlewares: Optional[List[Callable[..., Any]]] = None,
):
"""Put route decorator with PUT `method`
Examples
--------
Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator
```python
from aws_lambda_powertools import Tracer
from aws_lambda_powertools.event_handler import APIGatewayRestResolver
tracer = Tracer()
app = APIGatewayRestResolver()
@app.put("/put-call")
def simple_put():
put_data: dict = app.current_event.json_body
return {"message": put_data["value"]}
@tracer.capture_lambda_handler
def lambda_handler(event, context):
return app.resolve(event, context)
```
"""
return self.route(
rule,
"PUT",
cors,
compress,
cache_control,
summary,
description,
responses,
response_description,
tags,
operation_id,
include_in_schema,
middlewares,
)
def delete(
self,
rule: str,
cors: Optional[bool] = None,
compress: bool = False,
cache_control: Optional[str] = None,
summary: Optional[str] = None,
description: Optional[str] = None,
responses: Optional[Dict[int, Dict[str, Any]]] = None,
response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION,
tags: Optional[List[str]] = None,
operation_id: Optional[str] = None,
include_in_schema: bool = True,
middlewares: Optional[List[Callable[..., Any]]] = None,
):
"""Delete route decorator with DELETE `method`
Examples
--------
Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator
```python
from aws_lambda_powertools import Tracer
from aws_lambda_powertools.event_handler import APIGatewayRestResolver
tracer = Tracer()
app = APIGatewayRestResolver()
@app.delete("/delete-call")
def simple_delete():
return {"message": "deleted"}
@tracer.capture_lambda_handler
def lambda_handler(event, context):
return app.resolve(event, context)
```
"""
return self.route(
rule,
"DELETE",
cors,
compress,
cache_control,
summary,
description,
responses,
response_description,
tags,
operation_id,
include_in_schema,
middlewares,
)
def patch(
self,
rule: str,
cors: Optional[bool] = None,
compress: bool = False,
cache_control: Optional[str] = None,
summary: Optional[str] = None,
description: Optional[str] = None,
responses: Optional[Dict[int, Dict[str, Any]]] = None,
response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION,
tags: Optional[List[str]] = None,
operation_id: Optional[str] = None,
include_in_schema: bool = True,
middlewares: Optional[List[Callable]] = None,
):
"""Patch route decorator with PATCH `method`
Examples
--------
Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator
```python
from aws_lambda_powertools import Tracer
from aws_lambda_powertools.event_handler import APIGatewayRestResolver
tracer = Tracer()
app = APIGatewayRestResolver()
@app.patch("/patch-call")
def simple_patch():
patch_data: dict = app.current_event.json_body
patch_data["value"] = patched
return {"message": patch_data}
@tracer.capture_lambda_handler
def lambda_handler(event, context):
return app.resolve(event, context)
```
"""
return self.route(
rule,
"PATCH",
cors,
compress,
cache_control,
summary,
description,
responses,
response_description,
tags,
operation_id,
include_in_schema,
middlewares,
)
def _push_processed_stack_frame(self, frame: str):
"""
Add Current Middleware to the Middleware Stack Frames
The stack frames will be used when exceptions are thrown and Powertools
debug is enabled by developers.
"""
self.processed_stack_frames.append(frame)
def _reset_processed_stack(self):
"""Reset the Processed Stack Frames"""
self.processed_stack_frames.clear()
def append_context(self, **additional_context):
"""Append key=value data as routing context"""
self.context.update(**additional_context)
def clear_context(self):
"""Resets routing context"""
self.context.clear()
class MiddlewareFrame:
"""
Creates a Middle Stack Wrapper instance to be used as a "Frame" in the overall stack of
middleware functions. Each instance contains the current middleware and the next
middleware function to be called in the stack.
In this way the middleware stack is constructed in a recursive fashion, with each middleware
calling the next as a simple function call. The actual Python call-stack will contain
each MiddlewareStackWrapper "Frame", meaning any Middleware function can cause the
entire Middleware call chain to be exited early (short-circuited) by raising an exception
or by simply returning early with a custom Response. The decision to short-circuit the middleware
chain is at the user's discretion but instantly available due to the Wrapped nature of the
callable constructs in the Middleware stack and each Middleware function having complete control over
whether the "Next" handler in the stack is called or not.
Parameters
----------
current_middleware : Callable
The current middleware function to be called as a request is processed.
next_middleware : Callable
The next middleware in the middleware stack.
"""
def __init__(
self,
current_middleware: Callable[..., Any],
next_middleware: Callable[..., Any],
) -> None:
self.current_middleware: Callable[..., Any] = current_middleware
self.next_middleware: Callable[..., Any] = next_middleware
self._next_middleware_name = next_middleware.__name__
@property
def __name__(self) -> str: # noqa: A003
"""Current middleware name
It ensures backward compatibility with view functions being callable. This
improves debugging since we need both current and next middlewares/callable names.
"""
return self.current_middleware.__name__
def __str__(self) -> str:
"""Identify current middleware identity and call chain for debugging purposes."""
middleware_name = self.__name__
return f"[{middleware_name}] next call chain is {middleware_name} -> {self._next_middleware_name}"
def __call__(self, app: "ApiGatewayResolver") -> Union[Dict, Tuple, Response]:
"""
Call the middleware Frame to process the request.
Parameters
----------
app: BaseRouter
The router instance
Returns
-------
Union[Dict, Tuple, Response]
(tech-debt for backward compatibility). The response type should be a
Response object in all cases excepting when the original API route handler
is called which will return one of 3 outputs.
"""
# Do debug printing and push processed stack frame AFTER calling middleware
# else the stack frame text of `current calling next` is confusing.
logger.debug("MiddlewareFrame: %s", self)
app._push_processed_stack_frame(str(self))
return self.current_middleware(app, self.next_middleware)
def _registered_api_adapter(
app: "ApiGatewayResolver",
next_middleware: Callable[..., Any],
) -> Union[Dict, Tuple, Response]:
"""
Calls the registered API using the "_route_args" from the Resolver context to ensure the last call
in the chain will match the API route function signature and ensure that Powertools passes the API
route handler the expected arguments.
**IMPORTANT: This internal middleware ensures the actual API route is called with the correct call signature
and it MUST be the final frame in the middleware stack. This can only be removed when the API Route
function accepts `app: BaseRouter` as the first argument - which is the breaking change.
Parameters
----------
app: ApiGatewayResolver
The API Gateway resolver
next_middleware: Callable[..., Any]
The function to handle the API
Returns
-------
Response
The API Response Object
"""
route_args: Dict = app.context.get("_route_args", {})
logger.debug(f"Calling API Route Handler: {route_args}")
return app._to_response(next_middleware(**route_args))
class ApiGatewayResolver(BaseRouter):
"""API Gateway and ALB proxy resolver
Examples
--------
Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator
```python
from aws_lambda_powertools import Tracer
from aws_lambda_powertools.event_handler import APIGatewayRestResolver
tracer = Tracer()
app = APIGatewayRestResolver()
@app.get("/get-call")
def simple_get():
return {"message": "Foo"}
@app.post("/post-call")
def simple_post():
post_data: dict = app.current_event.json_body
return {"message": post_data["value"]}
@tracer.capture_lambda_handler
def lambda_handler(event, context):
return app.resolve(event, context)
```
"""
def __init__(
self,
proxy_type: Enum = ProxyEventType.APIGatewayProxyEvent,
cors: Optional[CORSConfig] = None,
debug: Optional[bool] = None,
serializer: Optional[Callable[[Dict], str]] = None,
strip_prefixes: Optional[List[Union[str, Pattern]]] = None,
enable_validation: bool = False,
):
"""
Parameters
----------
proxy_type: ProxyEventType
Proxy request type, defaults to API Gateway V1
cors: CORSConfig
Optionally configure and enabled CORS. Not each route will need to have to cors=True
debug: Optional[bool]
Enables debug mode, by default False. Can be also be enabled by "POWERTOOLS_DEV"
environment variable
serializer: Callable, optional
function to serialize `obj` to a JSON formatted `str`, by default json.dumps
strip_prefixes: List[Union[str, Pattern]], optional
optional list of prefixes to be removed from the request path before doing the routing.
This is often used with api gateways with multiple custom mappings.
Each prefix can be a static string or a compiled regex pattern
enable_validation: Optional[bool]
Enables validation of the request body against the route schema, by default False.
"""
self._proxy_type = proxy_type
self._dynamic_routes: List[Route] = []
self._static_routes: List[Route] = []
self._route_keys: List[str] = []
self._exception_handlers: Dict[Type, Callable] = {}
self._cors = cors
self._cors_enabled: bool = cors is not None
self._cors_methods: Set[str] = {"OPTIONS"}
self._debug = self._has_debug(debug)
self._enable_validation = enable_validation
self._strip_prefixes = strip_prefixes
self.context: Dict = {} # early init as customers might add context before event resolution
self.processed_stack_frames = []
self._response_builder_class = ResponseBuilder[BaseProxyEvent]
# Allow for a custom serializer or a concise json serialization
self._serializer = serializer or partial(json.dumps, separators=(",", ":"), cls=Encoder)
if self._enable_validation:
from aws_lambda_powertools.event_handler.middlewares.openapi_validation import OpenAPIValidationMiddleware
self.use([OpenAPIValidationMiddleware()])
# When using validation, we need to skip the serializer, as the middleware is doing it automatically.
# However, if the user is using a custom serializer, we need to abort.
if serializer:
raise ValueError("Cannot use a custom serializer when using validation")
# Install a dummy serializer
self._serializer = lambda args: args # type: ignore
def get_openapi_schema(
self,
*,
title: str = "Powertools API",
version: str = DEFAULT_API_VERSION,
openapi_version: str = DEFAULT_OPENAPI_VERSION,
summary: Optional[str] = None,
description: Optional[str] = None,
tags: Optional[List[str]] = None,
servers: Optional[List["Server"]] = None,
terms_of_service: Optional[str] = None,
contact: Optional["Contact"] = None,
license_info: Optional["License"] = None,
) -> "OpenAPI":
"""
Returns the OpenAPI schema as a pydantic model.
Parameters
----------
title: str
The title of the application.
version: str
The version of the OpenAPI document (which is distinct from the OpenAPI Specification version or the API
openapi_version: str, default = "3.1.0"
The version of the OpenAPI Specification (which the document uses).
summary: str, optional
A short summary of what the application does.
description: str, optional
A verbose explanation of the application behavior.
tags: List[str], optional
A list of tags used by the specification with additional metadata.
servers: List[Server], optional
An array of Server Objects, which provide connectivity information to a target server.
terms_of_service: str, optional
A URL to the Terms of Service for the API. MUST be in the format of a URL.
contact: Contact, optional
The contact information for the exposed API.
license_info: License, optional
The license information for the exposed API.
Returns
-------
OpenAPI: pydantic model
The OpenAPI schema as a pydantic model.
"""
from aws_lambda_powertools.event_handler.openapi.compat import (
GenerateJsonSchema,
get_compat_model_name_map,
get_definitions,
)
from aws_lambda_powertools.event_handler.openapi.models import OpenAPI, PathItem, Server
from aws_lambda_powertools.event_handler.openapi.types import (
COMPONENT_REF_TEMPLATE,
)
# Start with the bare minimum required for a valid OpenAPI schema
info: Dict[str, Any] = {"title": title, "version": version}
optional_fields = {
"summary": summary,
"description": description,
"termsOfService": terms_of_service,
"contact": contact,
"license": license_info,
}
info.update({field: value for field, value in optional_fields.items() if value})
output: Dict[str, Any] = {"openapi": openapi_version, "info": info}
if servers:
output["servers"] = servers
else:
# If the servers property is not provided, or is an empty array, the default value would be a Server Object
# with an url value of /.
output["servers"] = [Server(url="/")]
components: Dict[str, Dict[str, Any]] = {}
paths: Dict[str, Dict[str, Any]] = {}
operation_ids: Set[str] = set()
all_routes = self._dynamic_routes + self._static_routes
all_fields = self._get_fields_from_routes(all_routes)
model_name_map = get_compat_model_name_map(all_fields)
# Collect all models and definitions
schema_generator = GenerateJsonSchema(ref_template=COMPONENT_REF_TEMPLATE)
field_mapping, definitions = get_definitions(
fields=all_fields,
schema_generator=schema_generator,
model_name_map=model_name_map,
)
# Add routes to the OpenAPI schema
for route in all_routes:
if not route.include_in_schema:
continue
result = route._get_openapi_path(
dependant=route.dependant,
operation_ids=operation_ids,
model_name_map=model_name_map,
field_mapping=field_mapping,
)
if result:
path, path_definitions = result
if path:
paths.setdefault(route.path, {}).update(path)
if path_definitions:
definitions.update(path_definitions)
if definitions:
components["schemas"] = {k: definitions[k] for k in sorted(definitions)}
if components:
output["components"] = components
if tags:
output["tags"] = [{"name": tag} for tag in tags]
output["paths"] = {k: PathItem(**v) for k, v in paths.items()}
return OpenAPI(**output)
def get_openapi_json_schema(
self,
*,
title: str = "Powertools API",
version: str = DEFAULT_API_VERSION,
openapi_version: str = DEFAULT_OPENAPI_VERSION,
summary: Optional[str] = None,
description: Optional[str] = None,
tags: Optional[List[str]] = None,
servers: Optional[List["Server"]] = None,
terms_of_service: Optional[str] = None,
contact: Optional["Contact"] = None,
license_info: Optional["License"] = None,
) -> str:
"""
Returns the OpenAPI schema as a JSON serializable dict
Parameters
----------
title: str
The title of the application.
version: str
The version of the OpenAPI document (which is distinct from the OpenAPI Specification version or the API
openapi_version: str, default = "3.1.0"
The version of the OpenAPI Specification (which the document uses).
summary: str, optional
A short summary of what the application does.
description: str, optional
A verbose explanation of the application behavior.
tags: List[str], optional
A list of tags used by the specification with additional metadata.
servers: List[Server], optional
An array of Server Objects, which provide connectivity information to a target server.
terms_of_service: str, optional
A URL to the Terms of Service for the API. MUST be in the format of a URL.
contact: Contact, optional
The contact information for the exposed API.
license_info: License, optional
The license information for the exposed API.
Returns
-------
str
The OpenAPI schema as a JSON serializable dict.
"""
from aws_lambda_powertools.event_handler.openapi.compat import model_json
return model_json(
self.get_openapi_schema(
title=title,
version=version,
openapi_version=openapi_version,
summary=summary,
description=description,
tags=tags,
servers=servers,
terms_of_service=terms_of_service,
contact=contact,
license_info=license_info,
),
by_alias=True,
exclude_none=True,
indent=2,
)
def enable_swagger(
self,
*,
path: str = "/swagger",
title: str = "Powertools for AWS Lambda (Python) API",
version: str = DEFAULT_API_VERSION,
openapi_version: str = DEFAULT_OPENAPI_VERSION,
summary: Optional[str] = None,
description: Optional[str] = None,
tags: Optional[List[str]] = None,
servers: Optional[List["Server"]] = None,
terms_of_service: Optional[str] = None,
contact: Optional["Contact"] = None,
license_info: Optional["License"] = None,
swagger_base_url: Optional[str] = None,
middlewares: Optional[List[Callable[..., Response]]] = None,
):
"""
Returns the OpenAPI schema as a JSON serializable dict
Parameters
----------
path: str, default = "/swagger"
The path to the swagger UI.
title: str
The title of the application.
version: str
The version of the OpenAPI document (which is distinct from the OpenAPI Specification version or the API
openapi_version: str, default = "3.1.0"
The version of the OpenAPI Specification (which the document uses).
summary: str, optional
A short summary of what the application does.
description: str, optional
A verbose explanation of the application behavior.
tags: List[str], optional
A list of tags used by the specification with additional metadata.
servers: List[Server], optional
An array of Server Objects, which provide connectivity information to a target server.
terms_of_service: str, optional
A URL to the Terms of Service for the API. MUST be in the format of a URL.
contact: Contact, optional
The contact information for the exposed API.
license_info: License, optional
The license information for the exposed API.
swagger_base_url: str, optional
The base url for the swagger UI. If not provided, we will serve a recent version of the Swagger UI.
middlewares: List[Callable[..., Response]], optional
List of middlewares to be used for the swagger route.
"""
from aws_lambda_powertools.event_handler.openapi.models import Server
if not swagger_base_url:
@self.get("/swagger.js", include_in_schema=False)
def swagger_js():
body = Path.open(Path(__file__).parent / "openapi" / "swagger_ui" / "swagger-ui-bundle.min.js").read()
return Response(
status_code=200,
content_type="text/javascript",
body=body,
)
@self.get("/swagger.css", include_in_schema=False)
def swagger_css():
body = Path.open(Path(__file__).parent / "openapi" / "swagger_ui" / "swagger-ui.min.css").read()
return Response(
status_code=200,
content_type="text/css",
body=body,
)
@self.get(path, middlewares=middlewares, include_in_schema=False)
def swagger_handler():
base_path = self._get_base_path()
if swagger_base_url:
swagger_js = f"{swagger_base_url}/swagger-ui-bundle.min.js"
swagger_css = f"{swagger_base_url}/swagger-ui.min.css"
else:
swagger_js = f"{base_path}/swagger.js"
swagger_css = f"{base_path}/swagger.css"
openapi_servers = servers or [Server(url=(base_path or "/"))]
spec = self.get_openapi_json_schema(
title=title,
version=version,
openapi_version=openapi_version,
summary=summary,
description=description,
tags=tags,
servers=openapi_servers,
terms_of_service=terms_of_service,
contact=contact,
license_info=license_info,
)
body = generate_swagger_html(spec, swagger_js, swagger_css)
return Response(
status_code=200,
content_type="text/html",
body=body,
)
def route(
self,
rule: str,
method: Union[str, Union[List[str], Tuple[str]]],
cors: Optional[bool] = None,
compress: bool = False,
cache_control: Optional[str] = None,
summary: Optional[str] = None,
description: Optional[str] = None,
responses: Optional[Dict[int, Dict[str, Any]]] = None,
response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION,
tags: Optional[List[str]] = None,
operation_id: Optional[str] = None,
include_in_schema: bool = True,
middlewares: Optional[List[Callable[..., Any]]] = None,
):
"""Route decorator includes parameter `method`"""
def register_resolver(func: Callable):
methods = (method,) if isinstance(method, str) else method
logger.debug(f"Adding route using rule {rule} and methods: {','.join((m.upper() for m in methods))}")
cors_enabled = self._cors_enabled if cors is None else cors
for item in methods:
_route = Route(
item,
rule,
self._compile_regex(rule),
func,
cors_enabled,
compress,
cache_control,
summary,
description,
responses,
response_description,
tags,
operation_id,
include_in_schema,
middlewares,
)
# The more specific route wins.
# We store dynamic (/studies/{studyid}) and static routes (/studies/fetch) separately.
# Then attempt a match for static routes before dynamic routes.
# This ensures that the most specific route is prioritized and processed first (studies/fetch).
if _route.rule.groups > 0:
self._dynamic_routes.append(_route)
else:
self._static_routes.append(_route)
self._create_route_key(item, rule)
if cors_enabled:
logger.debug(f"Registering method {item.upper()} to Allow Methods in CORS")
self._cors_methods.add(item.upper())
return func
return register_resolver
def resolve(self, event, context) -> Dict[str, Any]:
"""Resolves the response based on the provide event and decorator routes
Parameters
----------
event: Dict[str, Any]
Event
context: LambdaContext
Lambda context
Returns
-------
dict
Returns the dict response
"""
if isinstance(event, BaseProxyEvent):
warnings.warn(
"You don't need to serialize event to Event Source Data Class when using Event Handler; "
"see issue #1152",
stacklevel=2,
)
event = event.raw_event
if self._debug:
print(self._json_dump(event))
# Populate router(s) dependencies without keeping a reference to each registered router
BaseRouter.current_event = self._to_proxy_event(event)
BaseRouter.lambda_context = context
response = self._resolve().build(self.current_event, self._cors)
# Debug print Processed Middlewares
if self._debug:
print("\nProcessed Middlewares:")
print("======================")
print("\n".join(self.processed_stack_frames))
print("======================")
self.clear_context()
return response
def __call__(self, event, context) -> Any:
return self.resolve(event, context)
def _create_route_key(self, item: str, rule: str):
route_key = item + rule
if route_key in self._route_keys:
warnings.warn(
f"A route like this was already registered. method: '{item}' rule: '{rule}'",
stacklevel=2,
)
self._route_keys.append(route_key)
def _get_base_path(self) -> str:
raise NotImplementedError()
@staticmethod
def _has_debug(debug: Optional[bool] = None) -> bool:
# It might have been explicitly switched off (debug=False)
if debug is not None:
return debug
return powertools_dev_is_set()
@staticmethod
def _compile_regex(rule: str, base_regex: str = _ROUTE_REGEX):
"""Precompile regex pattern
Logic
-----
1. Find any dynamic routes defined as <pattern>
e.g. @app.get("/accounts/<account_id>")
2. Create a new regex by substituting every dynamic route found as a named group (?P<group>),
and match whole words only (word boundary) instead of a greedy match
non-greedy example with word boundary
rule: '/accounts/<account_id>'
regex: r'/accounts/(?P<account_id>\\w+\\b)'
value: /accounts/123/some_other_path
account_id: 123
greedy example without word boundary
regex: r'/accounts/(?P<account_id>.+)'
value: /accounts/123/some_other_path
account_id: 123/some_other_path
3. Compiles a regex and include start (^) and end ($) in between for an exact match
NOTE: See #520 for context
"""
rule_regex: str = re.sub(_DYNAMIC_ROUTE_PATTERN, _NAMED_GROUP_BOUNDARY_PATTERN, rule)
return re.compile(base_regex.format(rule_regex))
def _to_proxy_event(self, event: Dict) -> BaseProxyEvent: # noqa: PLR0911 # ignore many returns
"""Convert the event dict to the corresponding data class"""
if self._proxy_type == ProxyEventType.APIGatewayProxyEvent:
logger.debug("Converting event to API Gateway REST API contract")
return APIGatewayProxyEvent(event)
if self._proxy_type == ProxyEventType.APIGatewayProxyEventV2:
logger.debug("Converting event to API Gateway HTTP API contract")
return APIGatewayProxyEventV2(event)
if self._proxy_type == ProxyEventType.BedrockAgentEvent:
logger.debug("Converting event to Bedrock Agent contract")
return BedrockAgentEvent(event)
if self._proxy_type == ProxyEventType.LambdaFunctionUrlEvent:
logger.debug("Converting event to Lambda Function URL contract")
return LambdaFunctionUrlEvent(event)
if self._proxy_type == ProxyEventType.VPCLatticeEvent:
logger.debug("Converting event to VPC Lattice contract")
return VPCLatticeEvent(event)
if self._proxy_type == ProxyEventType.VPCLatticeEventV2:
logger.debug("Converting event to VPC LatticeV2 contract")
return VPCLatticeEventV2(event)
logger.debug("Converting event to ALB contract")
return ALBEvent(event)
def _resolve(self) -> ResponseBuilder:
"""Resolves the response or return the not found response"""
method = self.current_event.http_method.upper()
path = self._remove_prefix(self.current_event.path)
for route in self._static_routes + self._dynamic_routes:
if method != route.method:
continue
match_results: Optional[Match] = route.rule.match(path)
if match_results:
logger.debug("Found a registered route. Calling function")
# Add matched Route reference into the Resolver context
self.append_context(_route=route, _path=path)
route_keys = self._convert_matches_into_route_keys(match_results)
return self._call_route(route, route_keys) # pass fn args
logger.debug(f"No match found for path {path} and method {method}")
return self._not_found(method)
def _remove_prefix(self, path: str) -> str:
"""Remove the configured prefix from the path"""
if not isinstance(self._strip_prefixes, list):
return path
for prefix in self._strip_prefixes:
if isinstance(prefix, str):
if path == prefix:
return "/"
if self._path_starts_with(path, prefix):
return path[len(prefix) :]
if isinstance(prefix, Pattern):
path = re.sub(prefix, "", path)
# When using regexes, we might get into a point where everything is removed
# from the string, so we check if it's empty and return /, since there's nothing
# else to strip anymore.
if not path:
return "/"
return path
def _convert_matches_into_route_keys(self, match: Match) -> Dict[str, str]:
"""Converts the regex match into a dict of route keys"""
return match.groupdict()
@staticmethod
def _path_starts_with(path: str, prefix: str):
"""Returns true if the `path` starts with a prefix plus a `/`"""
if not isinstance(prefix, str) or prefix == "":
return False
return path.startswith(prefix + "/")
def _not_found(self, method: str) -> ResponseBuilder:
"""Called when no matching route was found and includes support for the cors preflight response"""
headers: Dict[str, Union[str, List[str]]] = {}
if self._cors:
logger.debug("CORS is enabled, updating headers.")
headers.update(self._cors.to_dict(self.current_event.get_header_value("Origin")))
if method == "OPTIONS":
logger.debug("Pre-flight request detected. Returning CORS with null response")
headers["Access-Control-Allow-Methods"] = ",".join(sorted(self._cors_methods))
return ResponseBuilder(Response(status_code=204, content_type=None, headers=headers, body=""))
handler = self._lookup_exception_handler(NotFoundError)
if handler:
return self._response_builder_class(handler(NotFoundError()))
return self._response_builder_class(
Response(
status_code=HTTPStatus.NOT_FOUND.value,
content_type=content_types.APPLICATION_JSON,
headers=headers,
body=self._json_dump({"statusCode": HTTPStatus.NOT_FOUND.value, "message": "Not found"}),
),
)
def _call_route(self, route: Route, route_arguments: Dict[str, str]) -> ResponseBuilder:
"""Actually call the matching route with any provided keyword arguments."""
try:
# Reset Processed stack for Middleware (for debugging purposes)
self._reset_processed_stack()
return self._response_builder_class(
self._to_response(
route(router_middlewares=self._router_middlewares, app=self, route_arguments=route_arguments),
),
route,
)
except Exception as exc:
# If exception is handled then return the response builder to reduce noise
response_builder = self._call_exception_handler(exc, route)
if response_builder:
return response_builder
logger.exception(exc)
if self._debug:
# If the user has turned on debug mode,
# we'll let the original exception propagate, so
# they get more information about what went wrong.
return self._response_builder_class(
Response(
status_code=500,
content_type=content_types.TEXT_PLAIN,
body="".join(traceback.format_exc()),
),
route,
)
raise
def not_found(self, func: Optional[Callable] = None):
if func is None:
return self.exception_handler(NotFoundError)
return self.exception_handler(NotFoundError)(func)
def exception_handler(self, exc_class: Union[Type[Exception], List[Type[Exception]]]):
def register_exception_handler(func: Callable):
if isinstance(exc_class, list):
for exp in exc_class:
self._exception_handlers[exp] = func
else:
self._exception_handlers[exc_class] = func
return func
return register_exception_handler
def _lookup_exception_handler(self, exp_type: Type) -> Optional[Callable]:
# Use "Method Resolution Order" to allow for matching against a base class
# of an exception
for cls in exp_type.__mro__:
if cls in self._exception_handlers:
return self._exception_handlers[cls]
return None
def _call_exception_handler(self, exp: Exception, route: Route) -> Optional[ResponseBuilder]:
handler = self._lookup_exception_handler(type(exp))
if handler:
try:
return self._response_builder_class(handler(exp), route)
except ServiceError as service_error:
exp = service_error
if isinstance(exp, ServiceError):
return self._response_builder_class(
Response(
status_code=exp.status_code,
content_type=content_types.APPLICATION_JSON,
body=self._json_dump({"statusCode": exp.status_code, "message": exp.msg}),
),
route,
)
return None
def _to_response(self, result: Union[Dict, Tuple, Response]) -> Response:
"""Convert the route's result to a Response
3 main result types are supported:
- Dict[str, Any]: Rest api response with just the Dict to json stringify and content-type is set to
application/json
- Tuple[dict, int]: Same dict handling as above but with the option of including a status code
- Response: returned as is, and allows for more flexibility
"""
status_code = HTTPStatus.OK
if isinstance(result, Response):
return result
elif isinstance(result, tuple) and len(result) == 2:
# Unpack result dict and status code from tuple
result, status_code = result
logger.debug("Simple response detected, serializing return before constructing final response")
return Response(
status_code=status_code,
content_type=content_types.APPLICATION_JSON,
body=self._json_dump(result),
)
def _json_dump(self, obj: Any) -> str:
return self._serializer(obj)
def include_router(self, router: "Router", prefix: Optional[str] = None) -> None:
"""Adds all routes and context defined in a router
Parameters
----------
router : Router
The Router containing a list of routes to be registered after the existing routes
prefix : str, optional
An optional prefix to be added to the originally defined rule
"""
# Add reference to parent ApiGatewayResolver to support use cases where people subclass it to add custom logic
router.api_resolver = self
logger.debug("Merging App context with Router context")
self.context.update(**router.context)
logger.debug("Appending Router middlewares into App middlewares.")
self._router_middlewares = self._router_middlewares + router._router_middlewares
# use pointer to allow context clearance after event is processed e.g., resolve(evt, ctx)
router.context = self.context
# Iterate through the routes defined in the router to configure and apply middlewares for each route
for route, func in router._routes.items():
new_route = route
if prefix:
rule = route[0]
rule = prefix if rule == "/" else f"{prefix}{rule}"
new_route = (rule, *route[1:])
# Middlewares are stored by route separately - must grab them to include
# Middleware store the route without prefix, so we must not include prefix when grabbing
middlewares = router._routes_with_middleware.get(route)
# Need to use "type: ignore" here since mypy does not like a named parameter after
# tuple expansion since may cause duplicate named parameters in the function signature.
# In this case this is not possible since the tuple expansion is from a hashable source
# and the `middlewares` List is a non-hashable structure so will never be included.
# Still need to ignore for mypy checks or will cause failures (false-positive)
self.route(*new_route, middlewares=middlewares)(func) # type: ignore
@staticmethod
def _get_fields_from_routes(routes: Sequence[Route]) -> List["ModelField"]:
"""
Returns a list of fields from the routes
"""
from aws_lambda_powertools.event_handler.openapi.compat import ModelField
from aws_lambda_powertools.event_handler.openapi.dependant import (
get_flat_params,
)
body_fields_from_routes: List["ModelField"] = []
responses_from_routes: List["ModelField"] = []
request_fields_from_routes: List["ModelField"] = []
for route in routes:
if route.body_field:
if not isinstance(route.body_field, ModelField):
raise AssertionError("A request body myst be a Pydantic Field")
body_fields_from_routes.append(route.body_field)
params = get_flat_params(route.dependant)
request_fields_from_routes.extend(params)
if route.dependant.return_param:
responses_from_routes.append(route.dependant.return_param)
flat_models = list(responses_from_routes + request_fields_from_routes + body_fields_from_routes)
return flat_models
class Router(BaseRouter):
"""Router helper class to allow splitting ApiGatewayResolver into multiple files"""
def __init__(self):
self._routes: Dict[tuple, Callable] = {}
self._routes_with_middleware: Dict[tuple, List[Callable]] = {}
self.api_resolver: Optional[BaseRouter] = None
self.context = {} # early init as customers might add context before event resolution
def route(
self,
rule: str,
method: Union[str, Union[List[str], Tuple[str]]],
cors: Optional[bool] = None,
compress: bool = False,
cache_control: Optional[str] = None,
summary: Optional[str] = None,
description: Optional[str] = None,
responses: Optional[Dict[int, Dict[str, Any]]] = None,
response_description: Optional[str] = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION,
tags: Optional[List[str]] = None,
operation_id: Optional[str] = None,
include_in_schema: bool = True,
middlewares: Optional[List[Callable[..., Any]]] = None,
):
def register_route(func: Callable):
# Convert methods to tuple. It needs to be hashable as its part of the self._routes dict key
methods = (method,) if isinstance(method, str) else tuple(method)
route_key = (
rule,
methods,
cors,
compress,
cache_control,
summary,
description,
responses,
response_description,
tags,
operation_id,
include_in_schema,
)
# Collate Middleware for routes
if middlewares is not None:
for handler in middlewares:
if self._routes_with_middleware.get(route_key) is None:
self._routes_with_middleware[route_key] = [handler]
else:
self._routes_with_middleware[route_key].append(handler)
else:
self._routes_with_middleware[route_key] = []
self._routes[route_key] = func
return func
return register_route
class APIGatewayRestResolver(ApiGatewayResolver):
current_event: APIGatewayProxyEvent
def __init__(
self,
cors: Optional[CORSConfig] = None,
debug: Optional[bool] = None,
serializer: Optional[Callable[[Dict], str]] = None,
strip_prefixes: Optional[List[Union[str, Pattern]]] = None,
enable_validation: bool = False,
):
"""Amazon API Gateway REST and HTTP API v1 payload resolver"""
super().__init__(
ProxyEventType.APIGatewayProxyEvent,
cors,
debug,
serializer,
strip_prefixes,
enable_validation,
)
def _get_base_path(self) -> str:
# 3 different scenarios:
#
# 1. SAM local: even though a stage variable is sent to the Lambda function, it's not used in the path
# 2. API Gateway REST API: stage variable is used in the path
# 3. API Gateway REST Custom Domain: stage variable is not used in the path
#
# To solve the 3 scenarios, we try to match the beginning of the path with the stage variable
stage = self.current_event.request_context.stage
if stage and stage != "$default" and self.current_event.request_context.path.startswith(f"/{stage}"):
return f"/{stage}"
return ""
# override route to ignore trailing "/" in routes for REST API
def route(
self,
rule: str,
method: Union[str, Union[List[str], Tuple[str]]],
cors: Optional[bool] = None,
compress: bool = False,
cache_control: Optional[str] = None,
summary: Optional[str] = None,
description: Optional[str] = None,
responses: Optional[Dict[int, Dict[str, Any]]] = None,
response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION,
tags: Optional[List[str]] = None,
operation_id: Optional[str] = None,
include_in_schema: bool = True,
middlewares: Optional[List[Callable[..., Any]]] = None,
):
# NOTE: see #1552 for more context.
return super().route(
rule.rstrip("/"),
method,
cors,
compress,
cache_control,
summary,
description,
responses,
response_description,
tags,
operation_id,
include_in_schema,
middlewares,
)
# Override _compile_regex to exclude trailing slashes for route resolution
@staticmethod
def _compile_regex(rule: str, base_regex: str = _ROUTE_REGEX):
return super(APIGatewayRestResolver, APIGatewayRestResolver)._compile_regex(rule, "^{}/*$")
class APIGatewayHttpResolver(ApiGatewayResolver):
current_event: APIGatewayProxyEventV2
def __init__(
self,
cors: Optional[CORSConfig] = None,
debug: Optional[bool] = None,
serializer: Optional[Callable[[Dict], str]] = None,
strip_prefixes: Optional[List[Union[str, Pattern]]] = None,
enable_validation: bool = False,
):
"""Amazon API Gateway HTTP API v2 payload resolver"""
super().__init__(
ProxyEventType.APIGatewayProxyEventV2,
cors,
debug,
serializer,
strip_prefixes,
enable_validation,
)
def _get_base_path(self) -> str:
# 3 different scenarios:
#
# 1. SAM local: even though a stage variable is sent to the Lambda function, it's not used in the path
# 2. API Gateway HTTP API: stage variable is used in the path
# 3. API Gateway HTTP Custom Domain: stage variable is not used in the path
#
# To solve the 3 scenarios, we try to match the beginning of the path with the stage variable
stage = self.current_event.request_context.stage
if stage and stage != "$default" and self.current_event.request_context.http.path.startswith(f"/{stage}"):
return f"/{stage}"
return ""
class ALBResolver(ApiGatewayResolver):
current_event: ALBEvent
def __init__(
self,
cors: Optional[CORSConfig] = None,
debug: Optional[bool] = None,
serializer: Optional[Callable[[Dict], str]] = None,
strip_prefixes: Optional[List[Union[str, Pattern]]] = None,
enable_validation: bool = False,
):
"""Amazon Application Load Balancer (ALB) resolver"""
super().__init__(ProxyEventType.ALBEvent, cors, debug, serializer, strip_prefixes, enable_validation)
def _get_base_path(self) -> str:
# ALB doesn't have a stage variable, so we just return an empty string
return ""Classes
class ALBResolver (cors: Optional[CORSConfig] = None, debug: Optional[bool] = None, serializer: Optional[Callable[[Dict], str]] = None, strip_prefixes: Optional[List[Union[str, Pattern]]] = None, enable_validation: bool = False)-
API Gateway and ALB proxy resolver
Examples
Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator
from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.get("/get-call") def simple_get(): return {"message": "Foo"} @app.post("/post-call") def simple_post(): post_data: dict = app.current_event.json_body return {"message": post_data["value"]} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context)Amazon Application Load Balancer (ALB) resolver
Expand source code
class ALBResolver(ApiGatewayResolver): current_event: ALBEvent def __init__( self, cors: Optional[CORSConfig] = None, debug: Optional[bool] = None, serializer: Optional[Callable[[Dict], str]] = None, strip_prefixes: Optional[List[Union[str, Pattern]]] = None, enable_validation: bool = False, ): """Amazon Application Load Balancer (ALB) resolver""" super().__init__(ProxyEventType.ALBEvent, cors, debug, serializer, strip_prefixes, enable_validation) def _get_base_path(self) -> str: # ALB doesn't have a stage variable, so we just return an empty string return ""Ancestors
- ApiGatewayResolver
- BaseRouter
- abc.ABC
Class variables
var current_event : ALBEvent
Inherited members
class APIGatewayHttpResolver (cors: Optional[CORSConfig] = None, debug: Optional[bool] = None, serializer: Optional[Callable[[Dict], str]] = None, strip_prefixes: Optional[List[Union[str, Pattern]]] = None, enable_validation: bool = False)-
API Gateway and ALB proxy resolver
Examples
Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator
from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.get("/get-call") def simple_get(): return {"message": "Foo"} @app.post("/post-call") def simple_post(): post_data: dict = app.current_event.json_body return {"message": post_data["value"]} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context)Amazon API Gateway HTTP API v2 payload resolver
Expand source code
class APIGatewayHttpResolver(ApiGatewayResolver): current_event: APIGatewayProxyEventV2 def __init__( self, cors: Optional[CORSConfig] = None, debug: Optional[bool] = None, serializer: Optional[Callable[[Dict], str]] = None, strip_prefixes: Optional[List[Union[str, Pattern]]] = None, enable_validation: bool = False, ): """Amazon API Gateway HTTP API v2 payload resolver""" super().__init__( ProxyEventType.APIGatewayProxyEventV2, cors, debug, serializer, strip_prefixes, enable_validation, ) def _get_base_path(self) -> str: # 3 different scenarios: # # 1. SAM local: even though a stage variable is sent to the Lambda function, it's not used in the path # 2. API Gateway HTTP API: stage variable is used in the path # 3. API Gateway HTTP Custom Domain: stage variable is not used in the path # # To solve the 3 scenarios, we try to match the beginning of the path with the stage variable stage = self.current_event.request_context.stage if stage and stage != "$default" and self.current_event.request_context.http.path.startswith(f"/{stage}"): return f"/{stage}" return ""Ancestors
- ApiGatewayResolver
- BaseRouter
- abc.ABC
Class variables
var current_event : APIGatewayProxyEventV2
Inherited members
class APIGatewayRestResolver (cors: Optional[CORSConfig] = None, debug: Optional[bool] = None, serializer: Optional[Callable[[Dict], str]] = None, strip_prefixes: Optional[List[Union[str, Pattern]]] = None, enable_validation: bool = False)-
API Gateway and ALB proxy resolver
Examples
Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator
from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.get("/get-call") def simple_get(): return {"message": "Foo"} @app.post("/post-call") def simple_post(): post_data: dict = app.current_event.json_body return {"message": post_data["value"]} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context)Amazon API Gateway REST and HTTP API v1 payload resolver
Expand source code
class APIGatewayRestResolver(ApiGatewayResolver): current_event: APIGatewayProxyEvent def __init__( self, cors: Optional[CORSConfig] = None, debug: Optional[bool] = None, serializer: Optional[Callable[[Dict], str]] = None, strip_prefixes: Optional[List[Union[str, Pattern]]] = None, enable_validation: bool = False, ): """Amazon API Gateway REST and HTTP API v1 payload resolver""" super().__init__( ProxyEventType.APIGatewayProxyEvent, cors, debug, serializer, strip_prefixes, enable_validation, ) def _get_base_path(self) -> str: # 3 different scenarios: # # 1. SAM local: even though a stage variable is sent to the Lambda function, it's not used in the path # 2. API Gateway REST API: stage variable is used in the path # 3. API Gateway REST Custom Domain: stage variable is not used in the path # # To solve the 3 scenarios, we try to match the beginning of the path with the stage variable stage = self.current_event.request_context.stage if stage and stage != "$default" and self.current_event.request_context.path.startswith(f"/{stage}"): return f"/{stage}" return "" # override route to ignore trailing "/" in routes for REST API def route( self, rule: str, method: Union[str, Union[List[str], Tuple[str]]], cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION, tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None, ): # NOTE: see #1552 for more context. return super().route( rule.rstrip("/"), method, cors, compress, cache_control, summary, description, responses, response_description, tags, operation_id, include_in_schema, middlewares, ) # Override _compile_regex to exclude trailing slashes for route resolution @staticmethod def _compile_regex(rule: str, base_regex: str = _ROUTE_REGEX): return super(APIGatewayRestResolver, APIGatewayRestResolver)._compile_regex(rule, "^{}/*$")Ancestors
- ApiGatewayResolver
- BaseRouter
- abc.ABC
Class variables
var current_event : APIGatewayProxyEvent
Inherited members
class ApiGatewayResolver (proxy_type: enum.Enum = ProxyEventType.APIGatewayProxyEvent, cors: Optional[CORSConfig] = None, debug: Optional[bool] = None, serializer: Optional[Callable[[Dict], str]] = None, strip_prefixes: Optional[List[Union[str, Pattern]]] = None, enable_validation: bool = False)-
API Gateway and ALB proxy resolver
Examples
Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator
from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.get("/get-call") def simple_get(): return {"message": "Foo"} @app.post("/post-call") def simple_post(): post_data: dict = app.current_event.json_body return {"message": post_data["value"]} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context)Parameters
proxy_type:ProxyEventType- Proxy request type, defaults to API Gateway V1
cors:CORSConfig- Optionally configure and enabled CORS. Not each route will need to have to cors=True
debug:Optional[bool]- Enables debug mode, by default False. Can be also be enabled by "POWERTOOLS_DEV" environment variable
serializer:Callable, optional- function to serialize
objto a JSON formattedstr, by default json.dumps strip_prefixes:List[Union[str, Pattern]], optional- optional list of prefixes to be removed from the request path before doing the routing. This is often used with api gateways with multiple custom mappings. Each prefix can be a static string or a compiled regex pattern
enable_validation:Optional[bool]- Enables validation of the request body against the route schema, by default False.
Expand source code
class ApiGatewayResolver(BaseRouter): """API Gateway and ALB proxy resolver Examples -------- Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator ```python from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.get("/get-call") def simple_get(): return {"message": "Foo"} @app.post("/post-call") def simple_post(): post_data: dict = app.current_event.json_body return {"message": post_data["value"]} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context) ``` """ def __init__( self, proxy_type: Enum = ProxyEventType.APIGatewayProxyEvent, cors: Optional[CORSConfig] = None, debug: Optional[bool] = None, serializer: Optional[Callable[[Dict], str]] = None, strip_prefixes: Optional[List[Union[str, Pattern]]] = None, enable_validation: bool = False, ): """ Parameters ---------- proxy_type: ProxyEventType Proxy request type, defaults to API Gateway V1 cors: CORSConfig Optionally configure and enabled CORS. Not each route will need to have to cors=True debug: Optional[bool] Enables debug mode, by default False. Can be also be enabled by "POWERTOOLS_DEV" environment variable serializer: Callable, optional function to serialize `obj` to a JSON formatted `str`, by default json.dumps strip_prefixes: List[Union[str, Pattern]], optional optional list of prefixes to be removed from the request path before doing the routing. This is often used with api gateways with multiple custom mappings. Each prefix can be a static string or a compiled regex pattern enable_validation: Optional[bool] Enables validation of the request body against the route schema, by default False. """ self._proxy_type = proxy_type self._dynamic_routes: List[Route] = [] self._static_routes: List[Route] = [] self._route_keys: List[str] = [] self._exception_handlers: Dict[Type, Callable] = {} self._cors = cors self._cors_enabled: bool = cors is not None self._cors_methods: Set[str] = {"OPTIONS"} self._debug = self._has_debug(debug) self._enable_validation = enable_validation self._strip_prefixes = strip_prefixes self.context: Dict = {} # early init as customers might add context before event resolution self.processed_stack_frames = [] self._response_builder_class = ResponseBuilder[BaseProxyEvent] # Allow for a custom serializer or a concise json serialization self._serializer = serializer or partial(json.dumps, separators=(",", ":"), cls=Encoder) if self._enable_validation: from aws_lambda_powertools.event_handler.middlewares.openapi_validation import OpenAPIValidationMiddleware self.use([OpenAPIValidationMiddleware()]) # When using validation, we need to skip the serializer, as the middleware is doing it automatically. # However, if the user is using a custom serializer, we need to abort. if serializer: raise ValueError("Cannot use a custom serializer when using validation") # Install a dummy serializer self._serializer = lambda args: args # type: ignore def get_openapi_schema( self, *, title: str = "Powertools API", version: str = DEFAULT_API_VERSION, openapi_version: str = DEFAULT_OPENAPI_VERSION, summary: Optional[str] = None, description: Optional[str] = None, tags: Optional[List[str]] = None, servers: Optional[List["Server"]] = None, terms_of_service: Optional[str] = None, contact: Optional["Contact"] = None, license_info: Optional["License"] = None, ) -> "OpenAPI": """ Returns the OpenAPI schema as a pydantic model. Parameters ---------- title: str The title of the application. version: str The version of the OpenAPI document (which is distinct from the OpenAPI Specification version or the API openapi_version: str, default = "3.1.0" The version of the OpenAPI Specification (which the document uses). summary: str, optional A short summary of what the application does. description: str, optional A verbose explanation of the application behavior. tags: List[str], optional A list of tags used by the specification with additional metadata. servers: List[Server], optional An array of Server Objects, which provide connectivity information to a target server. terms_of_service: str, optional A URL to the Terms of Service for the API. MUST be in the format of a URL. contact: Contact, optional The contact information for the exposed API. license_info: License, optional The license information for the exposed API. Returns ------- OpenAPI: pydantic model The OpenAPI schema as a pydantic model. """ from aws_lambda_powertools.event_handler.openapi.compat import ( GenerateJsonSchema, get_compat_model_name_map, get_definitions, ) from aws_lambda_powertools.event_handler.openapi.models import OpenAPI, PathItem, Server from aws_lambda_powertools.event_handler.openapi.types import ( COMPONENT_REF_TEMPLATE, ) # Start with the bare minimum required for a valid OpenAPI schema info: Dict[str, Any] = {"title": title, "version": version} optional_fields = { "summary": summary, "description": description, "termsOfService": terms_of_service, "contact": contact, "license": license_info, } info.update({field: value for field, value in optional_fields.items() if value}) output: Dict[str, Any] = {"openapi": openapi_version, "info": info} if servers: output["servers"] = servers else: # If the servers property is not provided, or is an empty array, the default value would be a Server Object # with an url value of /. output["servers"] = [Server(url="/")] components: Dict[str, Dict[str, Any]] = {} paths: Dict[str, Dict[str, Any]] = {} operation_ids: Set[str] = set() all_routes = self._dynamic_routes + self._static_routes all_fields = self._get_fields_from_routes(all_routes) model_name_map = get_compat_model_name_map(all_fields) # Collect all models and definitions schema_generator = GenerateJsonSchema(ref_template=COMPONENT_REF_TEMPLATE) field_mapping, definitions = get_definitions( fields=all_fields, schema_generator=schema_generator, model_name_map=model_name_map, ) # Add routes to the OpenAPI schema for route in all_routes: if not route.include_in_schema: continue result = route._get_openapi_path( dependant=route.dependant, operation_ids=operation_ids, model_name_map=model_name_map, field_mapping=field_mapping, ) if result: path, path_definitions = result if path: paths.setdefault(route.path, {}).update(path) if path_definitions: definitions.update(path_definitions) if definitions: components["schemas"] = {k: definitions[k] for k in sorted(definitions)} if components: output["components"] = components if tags: output["tags"] = [{"name": tag} for tag in tags] output["paths"] = {k: PathItem(**v) for k, v in paths.items()} return OpenAPI(**output) def get_openapi_json_schema( self, *, title: str = "Powertools API", version: str = DEFAULT_API_VERSION, openapi_version: str = DEFAULT_OPENAPI_VERSION, summary: Optional[str] = None, description: Optional[str] = None, tags: Optional[List[str]] = None, servers: Optional[List["Server"]] = None, terms_of_service: Optional[str] = None, contact: Optional["Contact"] = None, license_info: Optional["License"] = None, ) -> str: """ Returns the OpenAPI schema as a JSON serializable dict Parameters ---------- title: str The title of the application. version: str The version of the OpenAPI document (which is distinct from the OpenAPI Specification version or the API openapi_version: str, default = "3.1.0" The version of the OpenAPI Specification (which the document uses). summary: str, optional A short summary of what the application does. description: str, optional A verbose explanation of the application behavior. tags: List[str], optional A list of tags used by the specification with additional metadata. servers: List[Server], optional An array of Server Objects, which provide connectivity information to a target server. terms_of_service: str, optional A URL to the Terms of Service for the API. MUST be in the format of a URL. contact: Contact, optional The contact information for the exposed API. license_info: License, optional The license information for the exposed API. Returns ------- str The OpenAPI schema as a JSON serializable dict. """ from aws_lambda_powertools.event_handler.openapi.compat import model_json return model_json( self.get_openapi_schema( title=title, version=version, openapi_version=openapi_version, summary=summary, description=description, tags=tags, servers=servers, terms_of_service=terms_of_service, contact=contact, license_info=license_info, ), by_alias=True, exclude_none=True, indent=2, ) def enable_swagger( self, *, path: str = "/swagger", title: str = "Powertools for AWS Lambda (Python) API", version: str = DEFAULT_API_VERSION, openapi_version: str = DEFAULT_OPENAPI_VERSION, summary: Optional[str] = None, description: Optional[str] = None, tags: Optional[List[str]] = None, servers: Optional[List["Server"]] = None, terms_of_service: Optional[str] = None, contact: Optional["Contact"] = None, license_info: Optional["License"] = None, swagger_base_url: Optional[str] = None, middlewares: Optional[List[Callable[..., Response]]] = None, ): """ Returns the OpenAPI schema as a JSON serializable dict Parameters ---------- path: str, default = "/swagger" The path to the swagger UI. title: str The title of the application. version: str The version of the OpenAPI document (which is distinct from the OpenAPI Specification version or the API openapi_version: str, default = "3.1.0" The version of the OpenAPI Specification (which the document uses). summary: str, optional A short summary of what the application does. description: str, optional A verbose explanation of the application behavior. tags: List[str], optional A list of tags used by the specification with additional metadata. servers: List[Server], optional An array of Server Objects, which provide connectivity information to a target server. terms_of_service: str, optional A URL to the Terms of Service for the API. MUST be in the format of a URL. contact: Contact, optional The contact information for the exposed API. license_info: License, optional The license information for the exposed API. swagger_base_url: str, optional The base url for the swagger UI. If not provided, we will serve a recent version of the Swagger UI. middlewares: List[Callable[..., Response]], optional List of middlewares to be used for the swagger route. """ from aws_lambda_powertools.event_handler.openapi.models import Server if not swagger_base_url: @self.get("/swagger.js", include_in_schema=False) def swagger_js(): body = Path.open(Path(__file__).parent / "openapi" / "swagger_ui" / "swagger-ui-bundle.min.js").read() return Response( status_code=200, content_type="text/javascript", body=body, ) @self.get("/swagger.css", include_in_schema=False) def swagger_css(): body = Path.open(Path(__file__).parent / "openapi" / "swagger_ui" / "swagger-ui.min.css").read() return Response( status_code=200, content_type="text/css", body=body, ) @self.get(path, middlewares=middlewares, include_in_schema=False) def swagger_handler(): base_path = self._get_base_path() if swagger_base_url: swagger_js = f"{swagger_base_url}/swagger-ui-bundle.min.js" swagger_css = f"{swagger_base_url}/swagger-ui.min.css" else: swagger_js = f"{base_path}/swagger.js" swagger_css = f"{base_path}/swagger.css" openapi_servers = servers or [Server(url=(base_path or "/"))] spec = self.get_openapi_json_schema( title=title, version=version, openapi_version=openapi_version, summary=summary, description=description, tags=tags, servers=openapi_servers, terms_of_service=terms_of_service, contact=contact, license_info=license_info, ) body = generate_swagger_html(spec, swagger_js, swagger_css) return Response( status_code=200, content_type="text/html", body=body, ) def route( self, rule: str, method: Union[str, Union[List[str], Tuple[str]]], cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION, tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None, ): """Route decorator includes parameter `method`""" def register_resolver(func: Callable): methods = (method,) if isinstance(method, str) else method logger.debug(f"Adding route using rule {rule} and methods: {','.join((m.upper() for m in methods))}") cors_enabled = self._cors_enabled if cors is None else cors for item in methods: _route = Route( item, rule, self._compile_regex(rule), func, cors_enabled, compress, cache_control, summary, description, responses, response_description, tags, operation_id, include_in_schema, middlewares, ) # The more specific route wins. # We store dynamic (/studies/{studyid}) and static routes (/studies/fetch) separately. # Then attempt a match for static routes before dynamic routes. # This ensures that the most specific route is prioritized and processed first (studies/fetch). if _route.rule.groups > 0: self._dynamic_routes.append(_route) else: self._static_routes.append(_route) self._create_route_key(item, rule) if cors_enabled: logger.debug(f"Registering method {item.upper()} to Allow Methods in CORS") self._cors_methods.add(item.upper()) return func return register_resolver def resolve(self, event, context) -> Dict[str, Any]: """Resolves the response based on the provide event and decorator routes Parameters ---------- event: Dict[str, Any] Event context: LambdaContext Lambda context Returns ------- dict Returns the dict response """ if isinstance(event, BaseProxyEvent): warnings.warn( "You don't need to serialize event to Event Source Data Class when using Event Handler; " "see issue #1152", stacklevel=2, ) event = event.raw_event if self._debug: print(self._json_dump(event)) # Populate router(s) dependencies without keeping a reference to each registered router BaseRouter.current_event = self._to_proxy_event(event) BaseRouter.lambda_context = context response = self._resolve().build(self.current_event, self._cors) # Debug print Processed Middlewares if self._debug: print("\nProcessed Middlewares:") print("======================") print("\n".join(self.processed_stack_frames)) print("======================") self.clear_context() return response def __call__(self, event, context) -> Any: return self.resolve(event, context) def _create_route_key(self, item: str, rule: str): route_key = item + rule if route_key in self._route_keys: warnings.warn( f"A route like this was already registered. method: '{item}' rule: '{rule}'", stacklevel=2, ) self._route_keys.append(route_key) def _get_base_path(self) -> str: raise NotImplementedError() @staticmethod def _has_debug(debug: Optional[bool] = None) -> bool: # It might have been explicitly switched off (debug=False) if debug is not None: return debug return powertools_dev_is_set() @staticmethod def _compile_regex(rule: str, base_regex: str = _ROUTE_REGEX): """Precompile regex pattern Logic ----- 1. Find any dynamic routes defined as <pattern> e.g. @app.get("/accounts/<account_id>") 2. Create a new regex by substituting every dynamic route found as a named group (?P<group>), and match whole words only (word boundary) instead of a greedy match non-greedy example with word boundary rule: '/accounts/<account_id>' regex: r'/accounts/(?P<account_id>\\w+\\b)' value: /accounts/123/some_other_path account_id: 123 greedy example without word boundary regex: r'/accounts/(?P<account_id>.+)' value: /accounts/123/some_other_path account_id: 123/some_other_path 3. Compiles a regex and include start (^) and end ($) in between for an exact match NOTE: See #520 for context """ rule_regex: str = re.sub(_DYNAMIC_ROUTE_PATTERN, _NAMED_GROUP_BOUNDARY_PATTERN, rule) return re.compile(base_regex.format(rule_regex)) def _to_proxy_event(self, event: Dict) -> BaseProxyEvent: # noqa: PLR0911 # ignore many returns """Convert the event dict to the corresponding data class""" if self._proxy_type == ProxyEventType.APIGatewayProxyEvent: logger.debug("Converting event to API Gateway REST API contract") return APIGatewayProxyEvent(event) if self._proxy_type == ProxyEventType.APIGatewayProxyEventV2: logger.debug("Converting event to API Gateway HTTP API contract") return APIGatewayProxyEventV2(event) if self._proxy_type == ProxyEventType.BedrockAgentEvent: logger.debug("Converting event to Bedrock Agent contract") return BedrockAgentEvent(event) if self._proxy_type == ProxyEventType.LambdaFunctionUrlEvent: logger.debug("Converting event to Lambda Function URL contract") return LambdaFunctionUrlEvent(event) if self._proxy_type == ProxyEventType.VPCLatticeEvent: logger.debug("Converting event to VPC Lattice contract") return VPCLatticeEvent(event) if self._proxy_type == ProxyEventType.VPCLatticeEventV2: logger.debug("Converting event to VPC LatticeV2 contract") return VPCLatticeEventV2(event) logger.debug("Converting event to ALB contract") return ALBEvent(event) def _resolve(self) -> ResponseBuilder: """Resolves the response or return the not found response""" method = self.current_event.http_method.upper() path = self._remove_prefix(self.current_event.path) for route in self._static_routes + self._dynamic_routes: if method != route.method: continue match_results: Optional[Match] = route.rule.match(path) if match_results: logger.debug("Found a registered route. Calling function") # Add matched Route reference into the Resolver context self.append_context(_route=route, _path=path) route_keys = self._convert_matches_into_route_keys(match_results) return self._call_route(route, route_keys) # pass fn args logger.debug(f"No match found for path {path} and method {method}") return self._not_found(method) def _remove_prefix(self, path: str) -> str: """Remove the configured prefix from the path""" if not isinstance(self._strip_prefixes, list): return path for prefix in self._strip_prefixes: if isinstance(prefix, str): if path == prefix: return "/" if self._path_starts_with(path, prefix): return path[len(prefix) :] if isinstance(prefix, Pattern): path = re.sub(prefix, "", path) # When using regexes, we might get into a point where everything is removed # from the string, so we check if it's empty and return /, since there's nothing # else to strip anymore. if not path: return "/" return path def _convert_matches_into_route_keys(self, match: Match) -> Dict[str, str]: """Converts the regex match into a dict of route keys""" return match.groupdict() @staticmethod def _path_starts_with(path: str, prefix: str): """Returns true if the `path` starts with a prefix plus a `/`""" if not isinstance(prefix, str) or prefix == "": return False return path.startswith(prefix + "/") def _not_found(self, method: str) -> ResponseBuilder: """Called when no matching route was found and includes support for the cors preflight response""" headers: Dict[str, Union[str, List[str]]] = {} if self._cors: logger.debug("CORS is enabled, updating headers.") headers.update(self._cors.to_dict(self.current_event.get_header_value("Origin"))) if method == "OPTIONS": logger.debug("Pre-flight request detected. Returning CORS with null response") headers["Access-Control-Allow-Methods"] = ",".join(sorted(self._cors_methods)) return ResponseBuilder(Response(status_code=204, content_type=None, headers=headers, body="")) handler = self._lookup_exception_handler(NotFoundError) if handler: return self._response_builder_class(handler(NotFoundError())) return self._response_builder_class( Response( status_code=HTTPStatus.NOT_FOUND.value, content_type=content_types.APPLICATION_JSON, headers=headers, body=self._json_dump({"statusCode": HTTPStatus.NOT_FOUND.value, "message": "Not found"}), ), ) def _call_route(self, route: Route, route_arguments: Dict[str, str]) -> ResponseBuilder: """Actually call the matching route with any provided keyword arguments.""" try: # Reset Processed stack for Middleware (for debugging purposes) self._reset_processed_stack() return self._response_builder_class( self._to_response( route(router_middlewares=self._router_middlewares, app=self, route_arguments=route_arguments), ), route, ) except Exception as exc: # If exception is handled then return the response builder to reduce noise response_builder = self._call_exception_handler(exc, route) if response_builder: return response_builder logger.exception(exc) if self._debug: # If the user has turned on debug mode, # we'll let the original exception propagate, so # they get more information about what went wrong. return self._response_builder_class( Response( status_code=500, content_type=content_types.TEXT_PLAIN, body="".join(traceback.format_exc()), ), route, ) raise def not_found(self, func: Optional[Callable] = None): if func is None: return self.exception_handler(NotFoundError) return self.exception_handler(NotFoundError)(func) def exception_handler(self, exc_class: Union[Type[Exception], List[Type[Exception]]]): def register_exception_handler(func: Callable): if isinstance(exc_class, list): for exp in exc_class: self._exception_handlers[exp] = func else: self._exception_handlers[exc_class] = func return func return register_exception_handler def _lookup_exception_handler(self, exp_type: Type) -> Optional[Callable]: # Use "Method Resolution Order" to allow for matching against a base class # of an exception for cls in exp_type.__mro__: if cls in self._exception_handlers: return self._exception_handlers[cls] return None def _call_exception_handler(self, exp: Exception, route: Route) -> Optional[ResponseBuilder]: handler = self._lookup_exception_handler(type(exp)) if handler: try: return self._response_builder_class(handler(exp), route) except ServiceError as service_error: exp = service_error if isinstance(exp, ServiceError): return self._response_builder_class( Response( status_code=exp.status_code, content_type=content_types.APPLICATION_JSON, body=self._json_dump({"statusCode": exp.status_code, "message": exp.msg}), ), route, ) return None def _to_response(self, result: Union[Dict, Tuple, Response]) -> Response: """Convert the route's result to a Response 3 main result types are supported: - Dict[str, Any]: Rest api response with just the Dict to json stringify and content-type is set to application/json - Tuple[dict, int]: Same dict handling as above but with the option of including a status code - Response: returned as is, and allows for more flexibility """ status_code = HTTPStatus.OK if isinstance(result, Response): return result elif isinstance(result, tuple) and len(result) == 2: # Unpack result dict and status code from tuple result, status_code = result logger.debug("Simple response detected, serializing return before constructing final response") return Response( status_code=status_code, content_type=content_types.APPLICATION_JSON, body=self._json_dump(result), ) def _json_dump(self, obj: Any) -> str: return self._serializer(obj) def include_router(self, router: "Router", prefix: Optional[str] = None) -> None: """Adds all routes and context defined in a router Parameters ---------- router : Router The Router containing a list of routes to be registered after the existing routes prefix : str, optional An optional prefix to be added to the originally defined rule """ # Add reference to parent ApiGatewayResolver to support use cases where people subclass it to add custom logic router.api_resolver = self logger.debug("Merging App context with Router context") self.context.update(**router.context) logger.debug("Appending Router middlewares into App middlewares.") self._router_middlewares = self._router_middlewares + router._router_middlewares # use pointer to allow context clearance after event is processed e.g., resolve(evt, ctx) router.context = self.context # Iterate through the routes defined in the router to configure and apply middlewares for each route for route, func in router._routes.items(): new_route = route if prefix: rule = route[0] rule = prefix if rule == "/" else f"{prefix}{rule}" new_route = (rule, *route[1:]) # Middlewares are stored by route separately - must grab them to include # Middleware store the route without prefix, so we must not include prefix when grabbing middlewares = router._routes_with_middleware.get(route) # Need to use "type: ignore" here since mypy does not like a named parameter after # tuple expansion since may cause duplicate named parameters in the function signature. # In this case this is not possible since the tuple expansion is from a hashable source # and the `middlewares` List is a non-hashable structure so will never be included. # Still need to ignore for mypy checks or will cause failures (false-positive) self.route(*new_route, middlewares=middlewares)(func) # type: ignore @staticmethod def _get_fields_from_routes(routes: Sequence[Route]) -> List["ModelField"]: """ Returns a list of fields from the routes """ from aws_lambda_powertools.event_handler.openapi.compat import ModelField from aws_lambda_powertools.event_handler.openapi.dependant import ( get_flat_params, ) body_fields_from_routes: List["ModelField"] = [] responses_from_routes: List["ModelField"] = [] request_fields_from_routes: List["ModelField"] = [] for route in routes: if route.body_field: if not isinstance(route.body_field, ModelField): raise AssertionError("A request body myst be a Pydantic Field") body_fields_from_routes.append(route.body_field) params = get_flat_params(route.dependant) request_fields_from_routes.extend(params) if route.dependant.return_param: responses_from_routes.append(route.dependant.return_param) flat_models = list(responses_from_routes + request_fields_from_routes + body_fields_from_routes) return flat_modelsAncestors
- BaseRouter
- abc.ABC
Subclasses
- ALBResolver
- APIGatewayHttpResolver
- APIGatewayRestResolver
- BedrockAgentResolver
- LambdaFunctionUrlResolver
- VPCLatticeResolver
- VPCLatticeV2Resolver
Methods
def enable_swagger(self, *, path: str = '/swagger', title: str = 'Powertools for AWS Lambda (Python) API', version: str = '1.0.0', openapi_version: str = '3.0.0', summary: Optional[str] = None, description: Optional[str] = None, tags: Optional[List[str]] = None, servers: Optional[List[ForwardRef('Server')]] = None, terms_of_service: Optional[str] = None, contact: Optional[ForwardRef('Contact')] = None, license_info: Optional[ForwardRef('License')] = None, swagger_base_url: Optional[str] = None, middlewares: Optional[List[Callable[..., Response]]] = None)-
Returns the OpenAPI schema as a JSON serializable dict
Parameters
path:str, default= "/swagger"- The path to the swagger UI.
title:str- The title of the application.
version:str- The version of the OpenAPI document (which is distinct from the OpenAPI Specification version or the API
openapi_version:str, default= "3.1.0"- The version of the OpenAPI Specification (which the document uses).
summary:str, optional- A short summary of what the application does.
description:str, optional- A verbose explanation of the application behavior.
tags:List[str], optional- A list of tags used by the specification with additional metadata.
servers:List[Server], optional- An array of Server Objects, which provide connectivity information to a target server.
terms_of_service:str, optional- A URL to the Terms of Service for the API. MUST be in the format of a URL.
contact:Contact, optional- The contact information for the exposed API.
license_info:License, optional- The license information for the exposed API.
swagger_base_url:str, optional- The base url for the swagger UI. If not provided, we will serve a recent version of the Swagger UI.
middlewares:List[Callable[…, Response]], optional- List of middlewares to be used for the swagger route.
Expand source code
def enable_swagger( self, *, path: str = "/swagger", title: str = "Powertools for AWS Lambda (Python) API", version: str = DEFAULT_API_VERSION, openapi_version: str = DEFAULT_OPENAPI_VERSION, summary: Optional[str] = None, description: Optional[str] = None, tags: Optional[List[str]] = None, servers: Optional[List["Server"]] = None, terms_of_service: Optional[str] = None, contact: Optional["Contact"] = None, license_info: Optional["License"] = None, swagger_base_url: Optional[str] = None, middlewares: Optional[List[Callable[..., Response]]] = None, ): """ Returns the OpenAPI schema as a JSON serializable dict Parameters ---------- path: str, default = "/swagger" The path to the swagger UI. title: str The title of the application. version: str The version of the OpenAPI document (which is distinct from the OpenAPI Specification version or the API openapi_version: str, default = "3.1.0" The version of the OpenAPI Specification (which the document uses). summary: str, optional A short summary of what the application does. description: str, optional A verbose explanation of the application behavior. tags: List[str], optional A list of tags used by the specification with additional metadata. servers: List[Server], optional An array of Server Objects, which provide connectivity information to a target server. terms_of_service: str, optional A URL to the Terms of Service for the API. MUST be in the format of a URL. contact: Contact, optional The contact information for the exposed API. license_info: License, optional The license information for the exposed API. swagger_base_url: str, optional The base url for the swagger UI. If not provided, we will serve a recent version of the Swagger UI. middlewares: List[Callable[..., Response]], optional List of middlewares to be used for the swagger route. """ from aws_lambda_powertools.event_handler.openapi.models import Server if not swagger_base_url: @self.get("/swagger.js", include_in_schema=False) def swagger_js(): body = Path.open(Path(__file__).parent / "openapi" / "swagger_ui" / "swagger-ui-bundle.min.js").read() return Response( status_code=200, content_type="text/javascript", body=body, ) @self.get("/swagger.css", include_in_schema=False) def swagger_css(): body = Path.open(Path(__file__).parent / "openapi" / "swagger_ui" / "swagger-ui.min.css").read() return Response( status_code=200, content_type="text/css", body=body, ) @self.get(path, middlewares=middlewares, include_in_schema=False) def swagger_handler(): base_path = self._get_base_path() if swagger_base_url: swagger_js = f"{swagger_base_url}/swagger-ui-bundle.min.js" swagger_css = f"{swagger_base_url}/swagger-ui.min.css" else: swagger_js = f"{base_path}/swagger.js" swagger_css = f"{base_path}/swagger.css" openapi_servers = servers or [Server(url=(base_path or "/"))] spec = self.get_openapi_json_schema( title=title, version=version, openapi_version=openapi_version, summary=summary, description=description, tags=tags, servers=openapi_servers, terms_of_service=terms_of_service, contact=contact, license_info=license_info, ) body = generate_swagger_html(spec, swagger_js, swagger_css) return Response( status_code=200, content_type="text/html", body=body, ) def exception_handler(self, exc_class: Union[Type[Exception], List[Type[Exception]]])-
Expand source code
def exception_handler(self, exc_class: Union[Type[Exception], List[Type[Exception]]]): def register_exception_handler(func: Callable): if isinstance(exc_class, list): for exp in exc_class: self._exception_handlers[exp] = func else: self._exception_handlers[exc_class] = func return func return register_exception_handler def get_openapi_json_schema(self, *, title: str = 'Powertools API', version: str = '1.0.0', openapi_version: str = '3.0.0', summary: Optional[str] = None, description: Optional[str] = None, tags: Optional[List[str]] = None, servers: Optional[List[ForwardRef('Server')]] = None, terms_of_service: Optional[str] = None, contact: Optional[ForwardRef('Contact')] = None, license_info: Optional[ForwardRef('License')] = None) ‑> str-
Returns the OpenAPI schema as a JSON serializable dict
Parameters
title:str- The title of the application.
version:str- The version of the OpenAPI document (which is distinct from the OpenAPI Specification version or the API
openapi_version:str, default= "3.1.0"- The version of the OpenAPI Specification (which the document uses).
summary:str, optional- A short summary of what the application does.
description:str, optional- A verbose explanation of the application behavior.
tags:List[str], optional- A list of tags used by the specification with additional metadata.
servers:List[Server], optional- An array of Server Objects, which provide connectivity information to a target server.
terms_of_service:str, optional- A URL to the Terms of Service for the API. MUST be in the format of a URL.
contact:Contact, optional- The contact information for the exposed API.
license_info:License, optional- The license information for the exposed API.
Returns
str- The OpenAPI schema as a JSON serializable dict.
Expand source code
def get_openapi_json_schema( self, *, title: str = "Powertools API", version: str = DEFAULT_API_VERSION, openapi_version: str = DEFAULT_OPENAPI_VERSION, summary: Optional[str] = None, description: Optional[str] = None, tags: Optional[List[str]] = None, servers: Optional[List["Server"]] = None, terms_of_service: Optional[str] = None, contact: Optional["Contact"] = None, license_info: Optional["License"] = None, ) -> str: """ Returns the OpenAPI schema as a JSON serializable dict Parameters ---------- title: str The title of the application. version: str The version of the OpenAPI document (which is distinct from the OpenAPI Specification version or the API openapi_version: str, default = "3.1.0" The version of the OpenAPI Specification (which the document uses). summary: str, optional A short summary of what the application does. description: str, optional A verbose explanation of the application behavior. tags: List[str], optional A list of tags used by the specification with additional metadata. servers: List[Server], optional An array of Server Objects, which provide connectivity information to a target server. terms_of_service: str, optional A URL to the Terms of Service for the API. MUST be in the format of a URL. contact: Contact, optional The contact information for the exposed API. license_info: License, optional The license information for the exposed API. Returns ------- str The OpenAPI schema as a JSON serializable dict. """ from aws_lambda_powertools.event_handler.openapi.compat import model_json return model_json( self.get_openapi_schema( title=title, version=version, openapi_version=openapi_version, summary=summary, description=description, tags=tags, servers=servers, terms_of_service=terms_of_service, contact=contact, license_info=license_info, ), by_alias=True, exclude_none=True, indent=2, ) def get_openapi_schema(self, *, title: str = 'Powertools API', version: str = '1.0.0', openapi_version: str = '3.0.0', summary: Optional[str] = None, description: Optional[str] = None, tags: Optional[List[str]] = None, servers: Optional[List[ForwardRef('Server')]] = None, terms_of_service: Optional[str] = None, contact: Optional[ForwardRef('Contact')] = None, license_info: Optional[ForwardRef('License')] = None) ‑> OpenAPI-
Returns the OpenAPI schema as a pydantic model.
Parameters
title:str- The title of the application.
version:str- The version of the OpenAPI document (which is distinct from the OpenAPI Specification version or the API
openapi_version:str, default= "3.1.0"- The version of the OpenAPI Specification (which the document uses).
summary:str, optional- A short summary of what the application does.
description:str, optional- A verbose explanation of the application behavior.
tags:List[str], optional- A list of tags used by the specification with additional metadata.
servers:List[Server], optional- An array of Server Objects, which provide connectivity information to a target server.
terms_of_service:str, optional- A URL to the Terms of Service for the API. MUST be in the format of a URL.
contact:Contact, optional- The contact information for the exposed API.
license_info:License, optional- The license information for the exposed API.
Returns
OpenAPI:pydantic model- The OpenAPI schema as a pydantic model.
Expand source code
def get_openapi_schema( self, *, title: str = "Powertools API", version: str = DEFAULT_API_VERSION, openapi_version: str = DEFAULT_OPENAPI_VERSION, summary: Optional[str] = None, description: Optional[str] = None, tags: Optional[List[str]] = None, servers: Optional[List["Server"]] = None, terms_of_service: Optional[str] = None, contact: Optional["Contact"] = None, license_info: Optional["License"] = None, ) -> "OpenAPI": """ Returns the OpenAPI schema as a pydantic model. Parameters ---------- title: str The title of the application. version: str The version of the OpenAPI document (which is distinct from the OpenAPI Specification version or the API openapi_version: str, default = "3.1.0" The version of the OpenAPI Specification (which the document uses). summary: str, optional A short summary of what the application does. description: str, optional A verbose explanation of the application behavior. tags: List[str], optional A list of tags used by the specification with additional metadata. servers: List[Server], optional An array of Server Objects, which provide connectivity information to a target server. terms_of_service: str, optional A URL to the Terms of Service for the API. MUST be in the format of a URL. contact: Contact, optional The contact information for the exposed API. license_info: License, optional The license information for the exposed API. Returns ------- OpenAPI: pydantic model The OpenAPI schema as a pydantic model. """ from aws_lambda_powertools.event_handler.openapi.compat import ( GenerateJsonSchema, get_compat_model_name_map, get_definitions, ) from aws_lambda_powertools.event_handler.openapi.models import OpenAPI, PathItem, Server from aws_lambda_powertools.event_handler.openapi.types import ( COMPONENT_REF_TEMPLATE, ) # Start with the bare minimum required for a valid OpenAPI schema info: Dict[str, Any] = {"title": title, "version": version} optional_fields = { "summary": summary, "description": description, "termsOfService": terms_of_service, "contact": contact, "license": license_info, } info.update({field: value for field, value in optional_fields.items() if value}) output: Dict[str, Any] = {"openapi": openapi_version, "info": info} if servers: output["servers"] = servers else: # If the servers property is not provided, or is an empty array, the default value would be a Server Object # with an url value of /. output["servers"] = [Server(url="/")] components: Dict[str, Dict[str, Any]] = {} paths: Dict[str, Dict[str, Any]] = {} operation_ids: Set[str] = set() all_routes = self._dynamic_routes + self._static_routes all_fields = self._get_fields_from_routes(all_routes) model_name_map = get_compat_model_name_map(all_fields) # Collect all models and definitions schema_generator = GenerateJsonSchema(ref_template=COMPONENT_REF_TEMPLATE) field_mapping, definitions = get_definitions( fields=all_fields, schema_generator=schema_generator, model_name_map=model_name_map, ) # Add routes to the OpenAPI schema for route in all_routes: if not route.include_in_schema: continue result = route._get_openapi_path( dependant=route.dependant, operation_ids=operation_ids, model_name_map=model_name_map, field_mapping=field_mapping, ) if result: path, path_definitions = result if path: paths.setdefault(route.path, {}).update(path) if path_definitions: definitions.update(path_definitions) if definitions: components["schemas"] = {k: definitions[k] for k in sorted(definitions)} if components: output["components"] = components if tags: output["tags"] = [{"name": tag} for tag in tags] output["paths"] = {k: PathItem(**v) for k, v in paths.items()} return OpenAPI(**output) def include_router(self, router: Router, prefix: Optional[str] = None) ‑> None-
Adds all routes and context defined in a router
Parameters
router:Router- The Router containing a list of routes to be registered after the existing routes
prefix:str, optional- An optional prefix to be added to the originally defined rule
Expand source code
def include_router(self, router: "Router", prefix: Optional[str] = None) -> None: """Adds all routes and context defined in a router Parameters ---------- router : Router The Router containing a list of routes to be registered after the existing routes prefix : str, optional An optional prefix to be added to the originally defined rule """ # Add reference to parent ApiGatewayResolver to support use cases where people subclass it to add custom logic router.api_resolver = self logger.debug("Merging App context with Router context") self.context.update(**router.context) logger.debug("Appending Router middlewares into App middlewares.") self._router_middlewares = self._router_middlewares + router._router_middlewares # use pointer to allow context clearance after event is processed e.g., resolve(evt, ctx) router.context = self.context # Iterate through the routes defined in the router to configure and apply middlewares for each route for route, func in router._routes.items(): new_route = route if prefix: rule = route[0] rule = prefix if rule == "/" else f"{prefix}{rule}" new_route = (rule, *route[1:]) # Middlewares are stored by route separately - must grab them to include # Middleware store the route without prefix, so we must not include prefix when grabbing middlewares = router._routes_with_middleware.get(route) # Need to use "type: ignore" here since mypy does not like a named parameter after # tuple expansion since may cause duplicate named parameters in the function signature. # In this case this is not possible since the tuple expansion is from a hashable source # and the `middlewares` List is a non-hashable structure so will never be included. # Still need to ignore for mypy checks or will cause failures (false-positive) self.route(*new_route, middlewares=middlewares)(func) # type: ignore def not_found(self, func: Optional[Callable] = None)-
Expand source code
def not_found(self, func: Optional[Callable] = None): if func is None: return self.exception_handler(NotFoundError) return self.exception_handler(NotFoundError)(func) def resolve(self, event, context) ‑> Dict[str, Any]-
Resolves the response based on the provide event and decorator routes
Parameters
event:Dict[str, Any]- Event
context:LambdaContext- Lambda context
Returns
dict- Returns the dict response
Expand source code
def resolve(self, event, context) -> Dict[str, Any]: """Resolves the response based on the provide event and decorator routes Parameters ---------- event: Dict[str, Any] Event context: LambdaContext Lambda context Returns ------- dict Returns the dict response """ if isinstance(event, BaseProxyEvent): warnings.warn( "You don't need to serialize event to Event Source Data Class when using Event Handler; " "see issue #1152", stacklevel=2, ) event = event.raw_event if self._debug: print(self._json_dump(event)) # Populate router(s) dependencies without keeping a reference to each registered router BaseRouter.current_event = self._to_proxy_event(event) BaseRouter.lambda_context = context response = self._resolve().build(self.current_event, self._cors) # Debug print Processed Middlewares if self._debug: print("\nProcessed Middlewares:") print("======================") print("\n".join(self.processed_stack_frames)) print("======================") self.clear_context() return response def route(self, rule: str, method: Union[str, List[str], Tuple[str]], cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = 'Successful Response', tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None)-
Route decorator includes parameter
methodExpand source code
def route( self, rule: str, method: Union[str, Union[List[str], Tuple[str]]], cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION, tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None, ): """Route decorator includes parameter `method`""" def register_resolver(func: Callable): methods = (method,) if isinstance(method, str) else method logger.debug(f"Adding route using rule {rule} and methods: {','.join((m.upper() for m in methods))}") cors_enabled = self._cors_enabled if cors is None else cors for item in methods: _route = Route( item, rule, self._compile_regex(rule), func, cors_enabled, compress, cache_control, summary, description, responses, response_description, tags, operation_id, include_in_schema, middlewares, ) # The more specific route wins. # We store dynamic (/studies/{studyid}) and static routes (/studies/fetch) separately. # Then attempt a match for static routes before dynamic routes. # This ensures that the most specific route is prioritized and processed first (studies/fetch). if _route.rule.groups > 0: self._dynamic_routes.append(_route) else: self._static_routes.append(_route) self._create_route_key(item, rule) if cors_enabled: logger.debug(f"Registering method {item.upper()} to Allow Methods in CORS") self._cors_methods.add(item.upper()) return func return register_resolver
Inherited members
class BaseRouter-
Helper class that provides a standard way to create an ABC using inheritance.
Expand source code
class BaseRouter(ABC): current_event: BaseProxyEvent lambda_context: LambdaContext context: dict _router_middlewares: List[Callable] = [] processed_stack_frames: List[str] = [] @abstractmethod def route( self, rule: str, method: Any, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION, tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None, ): raise NotImplementedError() def use(self, middlewares: List[Callable[..., Response]]) -> None: """ Add one or more global middlewares that run before/after route specific middleware. NOTE: Middlewares are called in insertion order. Parameters ---------- middlewares: List[Callable[..., Response]] List of global middlewares to be used Examples -------- Add middlewares to be used for every request processed by the Router. ```python from aws_lambda_powertools import Logger from aws_lambda_powertools.event_handler import APIGatewayRestResolver, Response from aws_lambda_powertools.event_handler.middlewares import NextMiddleware logger = Logger() app = APIGatewayRestResolver() def log_request_response(app: APIGatewayRestResolver, next_middleware: NextMiddleware) -> Response: logger.info("Incoming request", path=app.current_event.path, request=app.current_event.raw_event) result = next_middleware(app) logger.info("Response received", response=result.__dict__) return result app.use(middlewares=[log_request_response]) def lambda_handler(event, context): return app.resolve(event, context) ``` """ self._router_middlewares = self._router_middlewares + middlewares def get( self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION, tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None, ): """Get route decorator with GET `method` Examples -------- Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator ```python from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.get("/get-call") def simple_get(): return {"message": "Foo"} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context) ``` """ return self.route( rule, "GET", cors, compress, cache_control, summary, description, responses, response_description, tags, operation_id, include_in_schema, middlewares, ) def post( self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION, tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None, ): """Post route decorator with POST `method` Examples -------- Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator ```python from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.post("/post-call") def simple_post(): post_data: dict = app.current_event.json_body return {"message": post_data["value"]} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context) ``` """ return self.route( rule, "POST", cors, compress, cache_control, summary, description, responses, response_description, tags, operation_id, include_in_schema, middlewares, ) def put( self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION, tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None, ): """Put route decorator with PUT `method` Examples -------- Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator ```python from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.put("/put-call") def simple_put(): put_data: dict = app.current_event.json_body return {"message": put_data["value"]} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context) ``` """ return self.route( rule, "PUT", cors, compress, cache_control, summary, description, responses, response_description, tags, operation_id, include_in_schema, middlewares, ) def delete( self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION, tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None, ): """Delete route decorator with DELETE `method` Examples -------- Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator ```python from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.delete("/delete-call") def simple_delete(): return {"message": "deleted"} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context) ``` """ return self.route( rule, "DELETE", cors, compress, cache_control, summary, description, responses, response_description, tags, operation_id, include_in_schema, middlewares, ) def patch( self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION, tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable]] = None, ): """Patch route decorator with PATCH `method` Examples -------- Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator ```python from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.patch("/patch-call") def simple_patch(): patch_data: dict = app.current_event.json_body patch_data["value"] = patched return {"message": patch_data} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context) ``` """ return self.route( rule, "PATCH", cors, compress, cache_control, summary, description, responses, response_description, tags, operation_id, include_in_schema, middlewares, ) def _push_processed_stack_frame(self, frame: str): """ Add Current Middleware to the Middleware Stack Frames The stack frames will be used when exceptions are thrown and Powertools debug is enabled by developers. """ self.processed_stack_frames.append(frame) def _reset_processed_stack(self): """Reset the Processed Stack Frames""" self.processed_stack_frames.clear() def append_context(self, **additional_context): """Append key=value data as routing context""" self.context.update(**additional_context) def clear_context(self): """Resets routing context""" self.context.clear()Ancestors
- abc.ABC
Subclasses
Class variables
var context : dictvar current_event : BaseProxyEventvar lambda_context : LambdaContextvar processed_stack_frames : List[str]
Methods
def append_context(self, **additional_context)-
Append key=value data as routing context
Expand source code
def append_context(self, **additional_context): """Append key=value data as routing context""" self.context.update(**additional_context) def clear_context(self)-
Resets routing context
Expand source code
def clear_context(self): """Resets routing context""" self.context.clear() def delete(self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = 'Successful Response', tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None)-
Delete route decorator with DELETE
methodExamples
Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator
from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.delete("/delete-call") def simple_delete(): return {"message": "deleted"} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context)Expand source code
def delete( self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION, tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None, ): """Delete route decorator with DELETE `method` Examples -------- Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator ```python from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.delete("/delete-call") def simple_delete(): return {"message": "deleted"} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context) ``` """ return self.route( rule, "DELETE", cors, compress, cache_control, summary, description, responses, response_description, tags, operation_id, include_in_schema, middlewares, ) def get(self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = 'Successful Response', tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None)-
Get route decorator with GET
methodExamples
Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator
from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.get("/get-call") def simple_get(): return {"message": "Foo"} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context)Expand source code
def get( self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION, tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None, ): """Get route decorator with GET `method` Examples -------- Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator ```python from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.get("/get-call") def simple_get(): return {"message": "Foo"} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context) ``` """ return self.route( rule, "GET", cors, compress, cache_control, summary, description, responses, response_description, tags, operation_id, include_in_schema, middlewares, ) def patch(self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = 'Successful Response', tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable]] = None)-
Patch route decorator with PATCH
methodExamples
Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator
from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.patch("/patch-call") def simple_patch(): patch_data: dict = app.current_event.json_body patch_data["value"] = patched return {"message": patch_data} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context)Expand source code
def patch( self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION, tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable]] = None, ): """Patch route decorator with PATCH `method` Examples -------- Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator ```python from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.patch("/patch-call") def simple_patch(): patch_data: dict = app.current_event.json_body patch_data["value"] = patched return {"message": patch_data} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context) ``` """ return self.route( rule, "PATCH", cors, compress, cache_control, summary, description, responses, response_description, tags, operation_id, include_in_schema, middlewares, ) def post(self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = 'Successful Response', tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None)-
Post route decorator with POST
methodExamples
Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator
from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.post("/post-call") def simple_post(): post_data: dict = app.current_event.json_body return {"message": post_data["value"]} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context)Expand source code
def post( self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION, tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None, ): """Post route decorator with POST `method` Examples -------- Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator ```python from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.post("/post-call") def simple_post(): post_data: dict = app.current_event.json_body return {"message": post_data["value"]} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context) ``` """ return self.route( rule, "POST", cors, compress, cache_control, summary, description, responses, response_description, tags, operation_id, include_in_schema, middlewares, ) def put(self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = 'Successful Response', tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None)-
Put route decorator with PUT
methodExamples
Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator
from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.put("/put-call") def simple_put(): put_data: dict = app.current_event.json_body return {"message": put_data["value"]} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context)Expand source code
def put( self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION, tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None, ): """Put route decorator with PUT `method` Examples -------- Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator ```python from aws_lambda_powertools import Tracer from aws_lambda_powertools.event_handler import APIGatewayRestResolver tracer = Tracer() app = APIGatewayRestResolver() @app.put("/put-call") def simple_put(): put_data: dict = app.current_event.json_body return {"message": put_data["value"]} @tracer.capture_lambda_handler def lambda_handler(event, context): return app.resolve(event, context) ``` """ return self.route( rule, "PUT", cors, compress, cache_control, summary, description, responses, response_description, tags, operation_id, include_in_schema, middlewares, ) def route(self, rule: str, method: Any, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = 'Successful Response', tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None)-
Expand source code
@abstractmethod def route( self, rule: str, method: Any, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION, tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None, ): raise NotImplementedError() def use(self, middlewares: List[Callable[..., Response]]) ‑> None-
Add one or more global middlewares that run before/after route specific middleware.
NOTE: Middlewares are called in insertion order.
Parameters
middlewares:List[Callable[…, Response]]- List of global middlewares to be used
Examples
Add middlewares to be used for every request processed by the Router.
from aws_lambda_powertools import Logger from aws_lambda_powertools.event_handler import APIGatewayRestResolver, Response from aws_lambda_powertools.event_handler.middlewares import NextMiddleware logger = Logger() app = APIGatewayRestResolver() def log_request_response(app: APIGatewayRestResolver, next_middleware: NextMiddleware) -> Response: logger.info("Incoming request", path=app.current_event.path, request=app.current_event.raw_event) result = next_middleware(app) logger.info("Response received", response=result.__dict__) return result app.use(middlewares=[log_request_response]) def lambda_handler(event, context): return app.resolve(event, context)Expand source code
def use(self, middlewares: List[Callable[..., Response]]) -> None: """ Add one or more global middlewares that run before/after route specific middleware. NOTE: Middlewares are called in insertion order. Parameters ---------- middlewares: List[Callable[..., Response]] List of global middlewares to be used Examples -------- Add middlewares to be used for every request processed by the Router. ```python from aws_lambda_powertools import Logger from aws_lambda_powertools.event_handler import APIGatewayRestResolver, Response from aws_lambda_powertools.event_handler.middlewares import NextMiddleware logger = Logger() app = APIGatewayRestResolver() def log_request_response(app: APIGatewayRestResolver, next_middleware: NextMiddleware) -> Response: logger.info("Incoming request", path=app.current_event.path, request=app.current_event.raw_event) result = next_middleware(app) logger.info("Response received", response=result.__dict__) return result app.use(middlewares=[log_request_response]) def lambda_handler(event, context): return app.resolve(event, context) ``` """ self._router_middlewares = self._router_middlewares + middlewares
class CORSConfig (allow_origin: str = '*', extra_origins: Optional[List[str]] = None, allow_headers: Optional[List[str]] = None, expose_headers: Optional[List[str]] = None, max_age: Optional[int] = None, allow_credentials: bool = False)-
CORS Config
Examples
Simple cors example using the default permissive cors, not this should only be used during early prototyping
from aws_lambda_powertools.event_handler import APIGatewayRestResolver app = APIGatewayRestResolver() @app.get("/my/path", cors=True) def with_cors(): return {"message": "Foo"}Using a custom CORSConfig where
with_corsused the custom provided CORSConfig andwithout_corsdo not include any cors headers.from aws_lambda_powertools.event_handler.api_gateway import ( APIGatewayRestResolver, CORSConfig ) cors_config = CORSConfig( allow_origin="https://wwww.example.com/", extra_origins=["https://dev.example.com/"], expose_headers=["x-exposed-response-header"], allow_headers=["x-custom-request-header"], max_age=100, allow_credentials=True, ) app = APIGatewayRestResolver(cors=cors_config) @app.get("/my/path") def with_cors(): return {"message": "Foo"} @app.get("/another-one", cors=False) def without_cors(): return {"message": "Foo"}Parameters
allow_origin:str- The value of the
Access-Control-Allow-Originto send in the response. Defaults to "*", but should only be used during development. extra_origins:Optional[List[str]]- The list of additional allowed origins.
allow_headers:Optional[List[str]]- The list of additional allowed headers. This list is added to list of
built-in allowed headers:
Authorization,Content-Type,X-Amz-Date,X-Api-Key,X-Amz-Security-Token. expose_headers:Optional[List[str]]- A list of values to return for the Access-Control-Expose-Headers
max_age:Optional[int]- The value for the
Access-Control-Max-Age allow_credentials:bool- A boolean value that sets the value of
Access-Control-Allow-Credentials
Expand source code
class CORSConfig: """CORS Config Examples -------- Simple cors example using the default permissive cors, not this should only be used during early prototyping ```python from aws_lambda_powertools.event_handler import APIGatewayRestResolver app = APIGatewayRestResolver() @app.get("/my/path", cors=True) def with_cors(): return {"message": "Foo"} ``` Using a custom CORSConfig where `with_cors` used the custom provided CORSConfig and `without_cors` do not include any cors headers. ```python from aws_lambda_powertools.event_handler.api_gateway import ( APIGatewayRestResolver, CORSConfig ) cors_config = CORSConfig( allow_origin="https://wwww.example.com/", extra_origins=["https://dev.example.com/"], expose_headers=["x-exposed-response-header"], allow_headers=["x-custom-request-header"], max_age=100, allow_credentials=True, ) app = APIGatewayRestResolver(cors=cors_config) @app.get("/my/path") def with_cors(): return {"message": "Foo"} @app.get("/another-one", cors=False) def without_cors(): return {"message": "Foo"} ``` """ _REQUIRED_HEADERS = ["Authorization", "Content-Type", "X-Amz-Date", "X-Api-Key", "X-Amz-Security-Token"] def __init__( self, allow_origin: str = "*", extra_origins: Optional[List[str]] = None, allow_headers: Optional[List[str]] = None, expose_headers: Optional[List[str]] = None, max_age: Optional[int] = None, allow_credentials: bool = False, ): """ Parameters ---------- allow_origin: str The value of the `Access-Control-Allow-Origin` to send in the response. Defaults to "*", but should only be used during development. extra_origins: Optional[List[str]] The list of additional allowed origins. allow_headers: Optional[List[str]] The list of additional allowed headers. This list is added to list of built-in allowed headers: `Authorization`, `Content-Type`, `X-Amz-Date`, `X-Api-Key`, `X-Amz-Security-Token`. expose_headers: Optional[List[str]] A list of values to return for the Access-Control-Expose-Headers max_age: Optional[int] The value for the `Access-Control-Max-Age` allow_credentials: bool A boolean value that sets the value of `Access-Control-Allow-Credentials` """ self._allowed_origins = [allow_origin] if extra_origins: self._allowed_origins.extend(extra_origins) self.allow_headers = set(self._REQUIRED_HEADERS + (allow_headers or [])) self.expose_headers = expose_headers or [] self.max_age = max_age self.allow_credentials = allow_credentials def to_dict(self, origin: Optional[str]) -> Dict[str, str]: """Builds the configured Access-Control http headers""" # If there's no Origin, don't add any CORS headers if not origin: return {} # If the origin doesn't match any of the allowed origins, and we don't allow all origins ("*"), # don't add any CORS headers if origin not in self._allowed_origins and "*" not in self._allowed_origins: return {} # The origin matched an allowed origin, so return the CORS headers headers: Dict[str, str] = { "Access-Control-Allow-Origin": origin, "Access-Control-Allow-Headers": ",".join(sorted(self.allow_headers)), } if self.expose_headers: headers["Access-Control-Expose-Headers"] = ",".join(self.expose_headers) if self.max_age is not None: headers["Access-Control-Max-Age"] = str(self.max_age) if self.allow_credentials is True: headers["Access-Control-Allow-Credentials"] = "true" return headersMethods
def to_dict(self, origin: Optional[str]) ‑> Dict[str, str]-
Builds the configured Access-Control http headers
Expand source code
def to_dict(self, origin: Optional[str]) -> Dict[str, str]: """Builds the configured Access-Control http headers""" # If there's no Origin, don't add any CORS headers if not origin: return {} # If the origin doesn't match any of the allowed origins, and we don't allow all origins ("*"), # don't add any CORS headers if origin not in self._allowed_origins and "*" not in self._allowed_origins: return {} # The origin matched an allowed origin, so return the CORS headers headers: Dict[str, str] = { "Access-Control-Allow-Origin": origin, "Access-Control-Allow-Headers": ",".join(sorted(self.allow_headers)), } if self.expose_headers: headers["Access-Control-Expose-Headers"] = ",".join(self.expose_headers) if self.max_age is not None: headers["Access-Control-Max-Age"] = str(self.max_age) if self.allow_credentials is True: headers["Access-Control-Allow-Credentials"] = "true" return headers
class MiddlewareFrame (current_middleware: Callable[..., Any], next_middleware: Callable[..., Any])-
Creates a Middle Stack Wrapper instance to be used as a "Frame" in the overall stack of middleware functions. Each instance contains the current middleware and the next middleware function to be called in the stack.
In this way the middleware stack is constructed in a recursive fashion, with each middleware calling the next as a simple function call. The actual Python call-stack will contain each MiddlewareStackWrapper "Frame", meaning any Middleware function can cause the entire Middleware call chain to be exited early (short-circuited) by raising an exception or by simply returning early with a custom Response. The decision to short-circuit the middleware chain is at the user's discretion but instantly available due to the Wrapped nature of the callable constructs in the Middleware stack and each Middleware function having complete control over whether the "Next" handler in the stack is called or not.
Parameters
current_middleware:Callable- The current middleware function to be called as a request is processed.
next_middleware:Callable- The next middleware in the middleware stack.
Expand source code
class MiddlewareFrame: """ Creates a Middle Stack Wrapper instance to be used as a "Frame" in the overall stack of middleware functions. Each instance contains the current middleware and the next middleware function to be called in the stack. In this way the middleware stack is constructed in a recursive fashion, with each middleware calling the next as a simple function call. The actual Python call-stack will contain each MiddlewareStackWrapper "Frame", meaning any Middleware function can cause the entire Middleware call chain to be exited early (short-circuited) by raising an exception or by simply returning early with a custom Response. The decision to short-circuit the middleware chain is at the user's discretion but instantly available due to the Wrapped nature of the callable constructs in the Middleware stack and each Middleware function having complete control over whether the "Next" handler in the stack is called or not. Parameters ---------- current_middleware : Callable The current middleware function to be called as a request is processed. next_middleware : Callable The next middleware in the middleware stack. """ def __init__( self, current_middleware: Callable[..., Any], next_middleware: Callable[..., Any], ) -> None: self.current_middleware: Callable[..., Any] = current_middleware self.next_middleware: Callable[..., Any] = next_middleware self._next_middleware_name = next_middleware.__name__ @property def __name__(self) -> str: # noqa: A003 """Current middleware name It ensures backward compatibility with view functions being callable. This improves debugging since we need both current and next middlewares/callable names. """ return self.current_middleware.__name__ def __str__(self) -> str: """Identify current middleware identity and call chain for debugging purposes.""" middleware_name = self.__name__ return f"[{middleware_name}] next call chain is {middleware_name} -> {self._next_middleware_name}" def __call__(self, app: "ApiGatewayResolver") -> Union[Dict, Tuple, Response]: """ Call the middleware Frame to process the request. Parameters ---------- app: BaseRouter The router instance Returns ------- Union[Dict, Tuple, Response] (tech-debt for backward compatibility). The response type should be a Response object in all cases excepting when the original API route handler is called which will return one of 3 outputs. """ # Do debug printing and push processed stack frame AFTER calling middleware # else the stack frame text of `current calling next` is confusing. logger.debug("MiddlewareFrame: %s", self) app._push_processed_stack_frame(str(self)) return self.current_middleware(app, self.next_middleware) class ProxyEventType (*args, **kwds)-
An enumerations of the supported proxy event types.
Expand source code
class ProxyEventType(Enum): """An enumerations of the supported proxy event types.""" APIGatewayProxyEvent = "APIGatewayProxyEvent" APIGatewayProxyEventV2 = "APIGatewayProxyEventV2" ALBEvent = "ALBEvent" BedrockAgentEvent = "BedrockAgentEvent" VPCLatticeEvent = "VPCLatticeEvent" VPCLatticeEventV2 = "VPCLatticeEventV2" LambdaFunctionUrlEvent = "LambdaFunctionUrlEvent"Ancestors
- enum.Enum
Class variables
var ALBEventvar APIGatewayProxyEventvar APIGatewayProxyEventV2var BedrockAgentEventvar LambdaFunctionUrlEventvar VPCLatticeEventvar VPCLatticeEventV2
class Response (status_code: int, content_type: Optional[str] = None, body: Any = None, headers: Optional[Dict[str, Union[str, List[str]]]] = None, cookies: Optional[List[Cookie]] = None, compress: Optional[bool] = None)-
Response data class that provides greater control over what is returned from the proxy event
Parameters
status_code:int- Http status code, example 200
content_type:str- Optionally set the Content-Type header, example "application/json". Note this will be merged into any provided http headers
body:Union[str, bytes, None]- Optionally set the response body. Note: bytes body will be automatically base64 encoded
headers:dict[str, Union[str, List[str]]]- Optionally set specific http headers. Setting "Content-Type" here would override the
content_typevalue. cookies:list[Cookie]- Optionally set cookies.
Expand source code
class Response: """Response data class that provides greater control over what is returned from the proxy event""" def __init__( self, status_code: int, content_type: Optional[str] = None, body: Any = None, headers: Optional[Dict[str, Union[str, List[str]]]] = None, cookies: Optional[List[Cookie]] = None, compress: Optional[bool] = None, ): """ Parameters ---------- status_code: int Http status code, example 200 content_type: str Optionally set the Content-Type header, example "application/json". Note this will be merged into any provided http headers body: Union[str, bytes, None] Optionally set the response body. Note: bytes body will be automatically base64 encoded headers: dict[str, Union[str, List[str]]] Optionally set specific http headers. Setting "Content-Type" here would override the `content_type` value. cookies: list[Cookie] Optionally set cookies. """ self.status_code = status_code self.body = body self.base64_encoded = False self.headers: Dict[str, Union[str, List[str]]] = headers if headers else {} self.cookies = cookies or [] self.compress = compress self.content_type = content_type if content_type: self.headers.setdefault("Content-Type", content_type) def is_json(self) -> bool: """ Returns True if the response is JSON, based on the Content-Type. """ content_type = self.headers.get("Content-Type", "") if isinstance(content_type, list): content_type = content_type[0] return content_type.startswith("application/json")Methods
def is_json(self) ‑> bool-
Returns True if the response is JSON, based on the Content-Type.
Expand source code
def is_json(self) -> bool: """ Returns True if the response is JSON, based on the Content-Type. """ content_type = self.headers.get("Content-Type", "") if isinstance(content_type, list): content_type = content_type[0] return content_type.startswith("application/json")
class ResponseBuilder (response: Response, route: Optional[Route] = None)-
Internally used Response builder
Expand source code
class ResponseBuilder(Generic[ResponseEventT]): """Internally used Response builder""" def __init__(self, response: Response, route: Optional[Route] = None): self.response = response self.route = route def _add_cors(self, event: ResponseEventT, cors: CORSConfig): """Update headers to include the configured Access-Control headers""" self.response.headers.update(cors.to_dict(event.get_header_value("Origin"))) def _add_cache_control(self, cache_control: str): """Set the specified cache control headers for 200 http responses. For non-200 `no-cache` is used.""" cache_control = cache_control if self.response.status_code == 200 else "no-cache" self.response.headers["Cache-Control"] = cache_control @staticmethod def _has_compression_enabled( route_compression: bool, response_compression: Optional[bool], event: ResponseEventT, ) -> bool: """ Checks if compression is enabled. NOTE: Response compression takes precedence. Parameters ---------- route_compression: bool, optional A boolean indicating whether compression is enabled or not in the route setting. response_compression: bool, optional A boolean indicating whether compression is enabled or not in the response setting. event: ResponseEventT The event object containing the request details. Returns ------- bool True if compression is enabled and the "gzip" encoding is accepted, False otherwise. """ encoding: str = event.get_header_value( name="accept-encoding", default_value="", case_sensitive=False, ) # noqa: E501 if "gzip" in encoding: if response_compression is not None: return response_compression # e.g., Response(compress=False/True)) if route_compression: return True # e.g., @app.get(compress=True) return False def _compress(self): """Compress the response body, but only if `Accept-Encoding` headers includes gzip.""" self.response.headers["Content-Encoding"] = "gzip" if isinstance(self.response.body, str): logger.debug("Converting string response to bytes before compressing it") self.response.body = bytes(self.response.body, "utf-8") gzip = zlib.compressobj(9, zlib.DEFLATED, zlib.MAX_WBITS | 16) self.response.body = gzip.compress(self.response.body) + gzip.flush() def _route(self, event: ResponseEventT, cors: Optional[CORSConfig]): """Optionally handle any of the route's configure response handling""" if self.route is None: return if self.route.cors: self._add_cors(event, cors or CORSConfig()) if self.route.cache_control: self._add_cache_control(self.route.cache_control) if self._has_compression_enabled( route_compression=self.route.compress, response_compression=self.response.compress, event=event, ): self._compress() def build(self, event: ResponseEventT, cors: Optional[CORSConfig] = None) -> Dict[str, Any]: """Build the full response dict to be returned by the lambda""" self._route(event, cors) if isinstance(self.response.body, bytes): logger.debug("Encoding bytes response with base64") self.response.base64_encoded = True self.response.body = base64.b64encode(self.response.body).decode() return { "statusCode": self.response.status_code, "body": self.response.body, "isBase64Encoded": self.response.base64_encoded, **event.header_serializer().serialize(headers=self.response.headers, cookies=self.response.cookies), }Ancestors
- typing.Generic
Subclasses
Methods
def build(self, event: ~ResponseEventT, cors: Optional[CORSConfig] = None) ‑> Dict[str, Any]-
Build the full response dict to be returned by the lambda
Expand source code
def build(self, event: ResponseEventT, cors: Optional[CORSConfig] = None) -> Dict[str, Any]: """Build the full response dict to be returned by the lambda""" self._route(event, cors) if isinstance(self.response.body, bytes): logger.debug("Encoding bytes response with base64") self.response.base64_encoded = True self.response.body = base64.b64encode(self.response.body).decode() return { "statusCode": self.response.status_code, "body": self.response.body, "isBase64Encoded": self.response.base64_encoded, **event.header_serializer().serialize(headers=self.response.headers, cookies=self.response.cookies), }
class Route (method: str, path: str, rule: Pattern, func: Callable, cors: bool, compress: bool, cache_control: Optional[str], summary: Optional[str], description: Optional[str], responses: Optional[Dict[int, Dict[str, Any]]], response_description: Optional[str], tags: Optional[List[str]], operation_id: Optional[str], include_in_schema: bool, middlewares: Optional[List[Callable[..., Response]]])-
Internally used Route Configuration
Parameters
method:str- The HTTP method, example "GET"
path:str- The path of the route
rule:Pattern- The route rule, example "/my/path"
func:Callable- The route handler function
cors:bool- Whether or not to enable CORS for this route
compress:bool- Whether or not to enable gzip compression for this route
cache_control:Optional[str]- The cache control header value, example "max-age=3600"
summary:Optional[str]- The OpenAPI summary for this route
description:Optional[str]- The OpenAPI description for this route
responses:Optional[Dict[int, Dict[str, Any]]]- The OpenAPI responses for this route
response_description:Optional[str]- The OpenAPI response description for this route
tags:Optional[List[str]]- The list of OpenAPI tags to be used for this route
operation_id:Optional[str]- The OpenAPI operationId for this route
include_in_schema:bool- Whether or not to include this route in the OpenAPI schema
middlewares:Optional[List[Callable[…, Response]]]- The list of route middlewares to be called in order.
Expand source code
class Route: """Internally used Route Configuration""" def __init__( self, method: str, path: str, rule: Pattern, func: Callable, cors: bool, compress: bool, cache_control: Optional[str], summary: Optional[str], description: Optional[str], responses: Optional[Dict[int, Dict[str, Any]]], response_description: Optional[str], tags: Optional[List[str]], operation_id: Optional[str], include_in_schema: bool, middlewares: Optional[List[Callable[..., Response]]], ): """ Parameters ---------- method: str The HTTP method, example "GET" path: str The path of the route rule: Pattern The route rule, example "/my/path" func: Callable The route handler function cors: bool Whether or not to enable CORS for this route compress: bool Whether or not to enable gzip compression for this route cache_control: Optional[str] The cache control header value, example "max-age=3600" summary: Optional[str] The OpenAPI summary for this route description: Optional[str] The OpenAPI description for this route responses: Optional[Dict[int, Dict[str, Any]]] The OpenAPI responses for this route response_description: Optional[str] The OpenAPI response description for this route tags: Optional[List[str]] The list of OpenAPI tags to be used for this route operation_id: Optional[str] The OpenAPI operationId for this route include_in_schema: bool Whether or not to include this route in the OpenAPI schema middlewares: Optional[List[Callable[..., Response]]] The list of route middlewares to be called in order. """ self.method = method.upper() self.path = "/" if path.strip() == "" else path self.rule = rule self.func = func self._middleware_stack = func self.cors = cors self.compress = compress self.cache_control = cache_control self.summary = summary self.description = description self.responses = responses self.response_description = response_description self.tags = tags or [] self.include_in_schema = include_in_schema self.middlewares = middlewares or [] self.operation_id = operation_id or self._generate_operation_id() # _middleware_stack_built is used to ensure the middleware stack is only built once. self._middleware_stack_built = False # _dependant is used to cache the dependant model for the handler function self._dependant: Optional["Dependant"] = None # _body_field is used to cache the dependant model for the body field self._body_field: Optional["ModelField"] = None def __call__( self, router_middlewares: List[Callable], app: "ApiGatewayResolver", route_arguments: Dict[str, str], ) -> Union[Dict, Tuple, Response]: """Calling the Router class instance will trigger the following actions: 1. If Route Middleware stack has not been built, build it 2. Call the Route Middleware stack wrapping the original function handler with the app and route arguments. Parameters ---------- router_middlewares: List[Callable] The list of Router Middlewares (assigned to ALL routes) app: "ApiGatewayResolver" The ApiGatewayResolver instance to pass into the middleware stack route_arguments: Dict[str, str] The route arguments to pass to the app function (extracted from the Api Gateway Lambda Message structure from AWS) Returns ------- Union[Dict, Tuple, Response] API Response object in ALL cases, except when the original API route handler is called which may also return a Dict, Tuple, or Response. """ # Save CPU cycles by building middleware stack once if not self._middleware_stack_built: self._build_middleware_stack(router_middlewares=router_middlewares) # If debug is turned on then output the middleware stack to the console if app._debug: print(f"\nProcessing Route:::{self.func.__name__} ({app.context['_path']})") # Collect ALL middleware for debug printing - include internal _registered_api_adapter all_middlewares = router_middlewares + self.middlewares + [_registered_api_adapter] print("\nMiddleware Stack:") print("=================") print("\n".join(getattr(item, "__name__", "Unknown") for item in all_middlewares)) print("=================") # Add Route Arguments to app context app.append_context(_route_args=route_arguments) # Call the Middleware Wrapped _call_stack function handler with the app return self._middleware_stack(app) def _build_middleware_stack(self, router_middlewares: List[Callable[..., Any]]) -> None: """ Builds the middleware stack for the handler by wrapping each handler in an instance of MiddlewareWrapper which is used to contain the state of each middleware step. Middleware is represented by a standard Python Callable construct. Any Middleware handler wanting to short-circuit the middlware call chain can raise an exception to force the Python call stack created by the handler call-chain to naturally un-wind. This becomes a simple concept for developers to understand and reason with - no additional gymanstics other than plain old try ... except. Notes ----- The Route Middleware stack is processed in reverse order. This is so the stack of middleware handlers is applied in the order of being added to the handler. """ all_middlewares = router_middlewares + self.middlewares logger.debug(f"Building middleware stack: {all_middlewares}") # IMPORTANT: # this must be the last middleware in the stack (tech debt for backward # compatibility purposes) # # This adapter will: # 1. Call the registered API passing only the expected route arguments extracted from the path # and not the middleware. # 2. Adapt the response type of the route handler (Union[Dict, Tuple, Response]) # and normalise into a Response object so middleware will always have a constant signature all_middlewares.append(_registered_api_adapter) # Wrap the original route handler function in the middleware handlers # using the MiddlewareWrapper class callable construct in reverse order to # ensure middleware is applied in the order the user defined. # # Start with the route function and wrap from last to the first Middleware handler. for handler in reversed(all_middlewares): self._middleware_stack = MiddlewareFrame(current_middleware=handler, next_middleware=self._middleware_stack) self._middleware_stack_built = True @property def dependant(self) -> "Dependant": if self._dependant is None: from aws_lambda_powertools.event_handler.openapi.dependant import get_dependant self._dependant = get_dependant(path=self.path, call=self.func) return self._dependant @property def body_field(self) -> Optional["ModelField"]: if self._body_field is None: from aws_lambda_powertools.event_handler.openapi.dependant import get_body_field self._body_field = get_body_field(dependant=self.dependant, name=self.operation_id) return self._body_field def _get_openapi_path( self, *, dependant: "Dependant", operation_ids: Set[str], model_name_map: Dict["TypeModelOrEnum", str], field_mapping: Dict[Tuple["ModelField", Literal["validation", "serialization"]], "JsonSchemaValue"], ) -> Tuple[Dict[str, Any], Dict[str, Any]]: """ Returns the OpenAPI path and definitions for the route. """ from aws_lambda_powertools.event_handler.openapi.dependant import get_flat_params path = {} definitions: Dict[str, Any] = {} # Gather all the route parameters operation = self._openapi_operation_metadata(operation_ids=operation_ids) parameters: List[Dict[str, Any]] = [] all_route_params = get_flat_params(dependant) operation_params = self._openapi_operation_parameters( all_route_params=all_route_params, model_name_map=model_name_map, field_mapping=field_mapping, ) parameters.extend(operation_params) # Add the parameters to the OpenAPI operation if parameters: all_parameters = {(param["in"], param["name"]): param for param in parameters} required_parameters = {(param["in"], param["name"]): param for param in parameters if param.get("required")} all_parameters.update(required_parameters) operation["parameters"] = list(all_parameters.values()) # Add the request body to the OpenAPI operation, if applicable if self.method.upper() in METHODS_WITH_BODY: request_body_oai = self._openapi_operation_request_body( body_field=self.body_field, model_name_map=model_name_map, field_mapping=field_mapping, ) if request_body_oai: operation["requestBody"] = request_body_oai # Add the response to the OpenAPI operation if self.responses: # If the user supplied responses, we use them and don't set a default 200 response operation["responses"] = self.responses else: # Set the default 200 response responses = operation.setdefault("responses", self.responses or {}) success_response = responses.setdefault(200, {}) success_response["description"] = self.response_description or _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION success_response["content"] = {"application/json": {"schema": {}}} json_response = success_response["content"].setdefault("application/json", {}) # Add the response schema to the OpenAPI 200 response json_response.update( self._openapi_operation_return( param=dependant.return_param, model_name_map=model_name_map, field_mapping=field_mapping, ), ) # Add validation failure response (422) operation["responses"][422] = { "description": "Validation Error", "content": { "application/json": { "schema": {"$ref": COMPONENT_REF_PREFIX + "HTTPValidationError"}, }, }, } # Add the validation error schema to the definitions, but only if it hasn't been added yet if "ValidationError" not in definitions: definitions.update( { "ValidationError": validation_error_definition, "HTTPValidationError": validation_error_response_definition, }, ) path[self.method.lower()] = operation # Generate the response schema return path, definitions def _openapi_operation_summary(self) -> str: """ Returns the OpenAPI operation summary. If the user has not provided a summary, we generate one based on the route path and method. """ return self.summary or f"{self.method.upper()} {self.path}" def _openapi_operation_metadata(self, operation_ids: Set[str]) -> Dict[str, Any]: """ Returns the OpenAPI operation metadata. If the user has not provided a description, we generate one based on the route path and method. """ operation: Dict[str, Any] = {} # Ensure tags is added to the operation if self.tags: operation["tags"] = [{"name": tag for tag in self.tags}] # Ensure summary is added to the operation operation["summary"] = self._openapi_operation_summary() # Ensure description is added to the operation if self.description: operation["description"] = self.description # Ensure operationId is unique if self.operation_id in operation_ids: message = f"Duplicate Operation ID {self.operation_id} for function {self.func.__name__}" file_name = getattr(self.func, "__globals__", {}).get("__file__") if file_name: message += f" in {file_name}" warnings.warn(message, stacklevel=1) # Adds the operation operation_ids.add(self.operation_id) operation["operationId"] = self.operation_id return operation @staticmethod def _openapi_operation_request_body( *, body_field: Optional["ModelField"], model_name_map: Dict["TypeModelOrEnum", str], field_mapping: Dict[Tuple["ModelField", Literal["validation", "serialization"]], "JsonSchemaValue"], ) -> Optional[Dict[str, Any]]: """ Returns the OpenAPI operation request body. """ from aws_lambda_powertools.event_handler.openapi.compat import ModelField, get_schema_from_model_field from aws_lambda_powertools.event_handler.openapi.params import Body # Check that there is a body field and it's a Pydantic's model field if not body_field: return None if not isinstance(body_field, ModelField): raise AssertionError(f"Expected ModelField, got {body_field}") # Generate the request body schema body_schema = get_schema_from_model_field( field=body_field, model_name_map=model_name_map, field_mapping=field_mapping, ) field_info = cast(Body, body_field.field_info) request_media_type = field_info.media_type required = body_field.required request_body_oai: Dict[str, Any] = {} if required: request_body_oai["required"] = required # Generate the request body media type request_media_content: Dict[str, Any] = {"schema": body_schema} request_body_oai["content"] = {request_media_type: request_media_content} return request_body_oai @staticmethod def _openapi_operation_parameters( *, all_route_params: Sequence["ModelField"], model_name_map: Dict["TypeModelOrEnum", str], field_mapping: Dict[ Tuple["ModelField", Literal["validation", "serialization"]], "JsonSchemaValue", ], ) -> List[Dict[str, Any]]: """ Returns the OpenAPI operation parameters. """ from aws_lambda_powertools.event_handler.openapi.compat import ( get_schema_from_model_field, ) from aws_lambda_powertools.event_handler.openapi.params import Param parameters = [] for param in all_route_params: field_info = param.field_info field_info = cast(Param, field_info) if not field_info.include_in_schema: continue param_schema = get_schema_from_model_field( field=param, model_name_map=model_name_map, field_mapping=field_mapping, ) parameter = { "name": param.alias, "in": field_info.in_.value, "required": param.required, "schema": param_schema, } if field_info.description: parameter["description"] = field_info.description if field_info.deprecated: parameter["deprecated"] = field_info.deprecated parameters.append(parameter) return parameters @staticmethod def _openapi_operation_return( *, param: Optional["ModelField"], model_name_map: Dict["TypeModelOrEnum", str], field_mapping: Dict[ Tuple["ModelField", Literal["validation", "serialization"]], "JsonSchemaValue", ], ) -> Dict[str, Any]: """ Returns the OpenAPI operation return. """ if param is None: return {} from aws_lambda_powertools.event_handler.openapi.compat import ( get_schema_from_model_field, ) return_schema = get_schema_from_model_field( field=param, model_name_map=model_name_map, field_mapping=field_mapping, ) return {"schema": return_schema} def _generate_operation_id(self) -> str: operation_id = self.func.__name__ + self.path operation_id = re.sub(r"\W", "_", operation_id) operation_id = operation_id + "_" + self.method.lower() return operation_idInstance variables
var body_field : Optional[ModelField]-
Expand source code
@property def body_field(self) -> Optional["ModelField"]: if self._body_field is None: from aws_lambda_powertools.event_handler.openapi.dependant import get_body_field self._body_field = get_body_field(dependant=self.dependant, name=self.operation_id) return self._body_field var dependant : Dependant-
Expand source code
@property def dependant(self) -> "Dependant": if self._dependant is None: from aws_lambda_powertools.event_handler.openapi.dependant import get_dependant self._dependant = get_dependant(path=self.path, call=self.func) return self._dependant
class Router-
Router helper class to allow splitting ApiGatewayResolver into multiple files
Expand source code
class Router(BaseRouter): """Router helper class to allow splitting ApiGatewayResolver into multiple files""" def __init__(self): self._routes: Dict[tuple, Callable] = {} self._routes_with_middleware: Dict[tuple, List[Callable]] = {} self.api_resolver: Optional[BaseRouter] = None self.context = {} # early init as customers might add context before event resolution def route( self, rule: str, method: Union[str, Union[List[str], Tuple[str]]], cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: Optional[str] = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION, tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None, ): def register_route(func: Callable): # Convert methods to tuple. It needs to be hashable as its part of the self._routes dict key methods = (method,) if isinstance(method, str) else tuple(method) route_key = ( rule, methods, cors, compress, cache_control, summary, description, responses, response_description, tags, operation_id, include_in_schema, ) # Collate Middleware for routes if middlewares is not None: for handler in middlewares: if self._routes_with_middleware.get(route_key) is None: self._routes_with_middleware[route_key] = [handler] else: self._routes_with_middleware[route_key].append(handler) else: self._routes_with_middleware[route_key] = [] self._routes[route_key] = func return func return register_routeAncestors
- BaseRouter
- abc.ABC
Subclasses
Methods
def route(self, rule: str, method: Union[str, List[str], Tuple[str]], cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: Optional[str] = 'Successful Response', tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None)-
Expand source code
def route( self, rule: str, method: Union[str, Union[List[str], Tuple[str]]], cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, summary: Optional[str] = None, description: Optional[str] = None, responses: Optional[Dict[int, Dict[str, Any]]] = None, response_description: Optional[str] = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION, tags: Optional[List[str]] = None, operation_id: Optional[str] = None, include_in_schema: bool = True, middlewares: Optional[List[Callable[..., Any]]] = None, ): def register_route(func: Callable): # Convert methods to tuple. It needs to be hashable as its part of the self._routes dict key methods = (method,) if isinstance(method, str) else tuple(method) route_key = ( rule, methods, cors, compress, cache_control, summary, description, responses, response_description, tags, operation_id, include_in_schema, ) # Collate Middleware for routes if middlewares is not None: for handler in middlewares: if self._routes_with_middleware.get(route_key) is None: self._routes_with_middleware[route_key] = [handler] else: self._routes_with_middleware[route_key].append(handler) else: self._routes_with_middleware[route_key] = [] self._routes[route_key] = func return func return register_route
Inherited members