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 typing import (
Any,
Callable,
Dict,
List,
Match,
Optional,
Pattern,
Set,
Tuple,
Type,
Union,
)
from aws_lambda_powertools.event_handler import content_types
from aws_lambda_powertools.event_handler.exceptions import NotFoundError, ServiceError
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.utilities.data_classes import (
ALBEvent,
APIGatewayProxyEvent,
APIGatewayProxyEventV2,
LambdaFunctionUrlEvent,
)
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 = "%<> \[\]{}|^" # noqa: W605
_NAMED_GROUP_BOUNDARY_PATTERN = rf"(?P\1[{_SAFE_URI}{_UNSAFE_URI}\\w]+)"
_ROUTE_REGEX = "^{}$"
class ProxyEventType(Enum):
"""An enumerations of the supported proxy event types."""
APIGatewayProxyEvent = "APIGatewayProxyEvent"
APIGatewayProxyEventV2 = "APIGatewayProxyEventV2"
ALBEvent = "ALBEvent"
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: Union[str, bytes, None] = None,
headers: Optional[Dict[str, Union[str, List[str]]]] = None,
cookies: Optional[List[Cookie]] = 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 []
if content_type:
self.headers.setdefault("Content-Type", content_type)
class Route:
"""Internally used Route Configuration"""
def __init__(
self, method: str, rule: Pattern, func: Callable, cors: bool, compress: bool, cache_control: Optional[str]
):
self.method = method.upper()
self.rule = rule
self.func = func
self.cors = cors
self.compress = compress
self.cache_control = cache_control
class ResponseBuilder:
"""Internally used Response builder"""
def __init__(self, response: Response, route: Optional[Route] = None):
self.response = response
self.route = route
def _add_cors(self, event: BaseProxyEvent, 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
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: BaseProxyEvent, 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.route.compress and "gzip" in (event.get_header_value("accept-encoding", "") or ""):
self._compress()
def build(self, event: BaseProxyEvent, 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
@abstractmethod
def route(
self,
rule: str,
method: Any,
cors: Optional[bool] = None,
compress: bool = False,
cache_control: Optional[str] = None,
):
raise NotImplementedError()
def get(self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = 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)
def post(self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = 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)
def put(self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = 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)
def delete(
self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = 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)
def patch(
self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = 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)
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 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[str]] = None,
):
"""
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[str], 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.
"""
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._strip_prefixes = strip_prefixes
self.context: Dict = {} # early init as customers might add context before event resolution
# Allow for a custom serializer or a concise json serialization
self._serializer = serializer or partial(json.dumps, separators=(",", ":"), cls=Encoder)
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,
):
"""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))}")
if cors is None:
cors_enabled = self._cors_enabled
else:
cors_enabled = cors
for item in methods:
_route = Route(item, self._compile_regex(rule), func, cors_enabled, compress, cache_control)
# 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)
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)
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)
self.clear_context()
return response
def __call__(self, event, context) -> Any:
return self.resolve(event, context)
@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:
"""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.LambdaFunctionUrlEvent:
logger.debug("Converting event to Lambda Function URL contract")
return LambdaFunctionUrlEvent(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")
return self._call_route(route, match_results.groupdict()) # 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 path == prefix:
return "/"
if self._path_starts_with(path, prefix):
return path[len(prefix) :]
return path
@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 ResponseBuilder(handler(NotFoundError()))
return ResponseBuilder(
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, args: Dict[str, str]) -> ResponseBuilder:
"""Actually call the matching route with any provided keyword arguments."""
try:
return ResponseBuilder(self._to_response(route.func(**args)), route)
except Exception as exc:
response_builder = self._call_exception_handler(exc, route)
if response_builder:
return response_builder
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 ResponseBuilder(
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 ResponseBuilder(handler(exp), route)
except ServiceError as service_error:
exp = service_error
if isinstance(exp, ServiceError):
return ResponseBuilder(
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
# Merge app and router context
self.context.update(**router.context)
# use pointer to allow context clearance after event is processed e.g., resolve(evt, ctx)
router.context = self.context
for route, func in router._routes.items():
if prefix:
rule = route[0]
rule = prefix if rule == "/" else f"{prefix}{rule}"
route = (rule, *route[1:])
self.route(*route)(func)
class Router(BaseRouter):
"""Router helper class to allow splitting ApiGatewayResolver into multiple files"""
def __init__(self):
self._routes: Dict[tuple, 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,
):
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)
self._routes[(rule, methods, cors, compress, cache_control)] = 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[str]] = None,
):
"""Amazon API Gateway REST and HTTP API v1 payload resolver"""
super().__init__(ProxyEventType.APIGatewayProxyEvent, cors, debug, serializer, strip_prefixes)
# 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,
):
# NOTE: see #1552 for more context.
return super().route(rule.rstrip("/"), method, cors, compress, cache_control)
# 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[str]] = None,
):
"""Amazon API Gateway HTTP API v2 payload resolver"""
super().__init__(ProxyEventType.APIGatewayProxyEventV2, cors, debug, serializer, strip_prefixes)
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[str]] = None,
):
"""Amazon Application Load Balancer (ALB) resolver"""
super().__init__(ProxyEventType.ALBEvent, cors, debug, serializer, strip_prefixes)
Classes
class ALBResolver (cors: Optional[CORSConfig] = None, debug: Optional[bool] = None, serializer: Optional[Callable[[Dict], str]] = None, strip_prefixes: Optional[List[str]] = None)
-
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[str]] = None, ): """Amazon Application Load Balancer (ALB) resolver""" super().__init__(ProxyEventType.ALBEvent, cors, debug, serializer, strip_prefixes)
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[str]] = None)
-
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[str]] = None, ): """Amazon API Gateway HTTP API v2 payload resolver""" super().__init__(ProxyEventType.APIGatewayProxyEventV2, cors, debug, serializer, strip_prefixes)
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[str]] = None)
-
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[str]] = None, ): """Amazon API Gateway REST and HTTP API v1 payload resolver""" super().__init__(ProxyEventType.APIGatewayProxyEvent, cors, debug, serializer, strip_prefixes) # 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, ): # NOTE: see #1552 for more context. return super().route(rule.rstrip("/"), method, cors, compress, cache_control) # 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[str]] = None)
-
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
obj
to a JSON formattedstr
, by default json.dumps strip_prefixes
:List[str]
, 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.
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[str]] = None, ): """ 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[str], 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. """ 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._strip_prefixes = strip_prefixes self.context: Dict = {} # early init as customers might add context before event resolution # Allow for a custom serializer or a concise json serialization self._serializer = serializer or partial(json.dumps, separators=(",", ":"), cls=Encoder) 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, ): """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))}") if cors is None: cors_enabled = self._cors_enabled else: cors_enabled = cors for item in methods: _route = Route(item, self._compile_regex(rule), func, cors_enabled, compress, cache_control) # 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) 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) 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) self.clear_context() return response def __call__(self, event, context) -> Any: return self.resolve(event, context) @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: """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.LambdaFunctionUrlEvent: logger.debug("Converting event to Lambda Function URL contract") return LambdaFunctionUrlEvent(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") return self._call_route(route, match_results.groupdict()) # 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 path == prefix: return "/" if self._path_starts_with(path, prefix): return path[len(prefix) :] return path @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 ResponseBuilder(handler(NotFoundError())) return ResponseBuilder( 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, args: Dict[str, str]) -> ResponseBuilder: """Actually call the matching route with any provided keyword arguments.""" try: return ResponseBuilder(self._to_response(route.func(**args)), route) except Exception as exc: response_builder = self._call_exception_handler(exc, route) if response_builder: return response_builder 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 ResponseBuilder( 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 ResponseBuilder(handler(exp), route) except ServiceError as service_error: exp = service_error if isinstance(exp, ServiceError): return ResponseBuilder( 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 # Merge app and router context self.context.update(**router.context) # use pointer to allow context clearance after event is processed e.g., resolve(evt, ctx) router.context = self.context for route, func in router._routes.items(): if prefix: rule = route[0] rule = prefix if rule == "/" else f"{prefix}{rule}" route = (rule, *route[1:]) self.route(*route)(func)
Ancestors
- BaseRouter
- abc.ABC
Subclasses
Methods
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 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 # Merge app and router context self.context.update(**router.context) # use pointer to allow context clearance after event is processed e.g., resolve(evt, ctx) router.context = self.context for route, func in router._routes.items(): if prefix: rule = route[0] rule = prefix if rule == "/" else f"{prefix}{rule}" route = (rule, *route[1:]) self.route(*route)(func)
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) 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)
-
Route decorator includes parameter
method
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, ): """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))}") if cors is None: cors_enabled = self._cors_enabled else: cors_enabled = cors for item in methods: _route = Route(item, self._compile_regex(rule), func, cors_enabled, compress, cache_control) # 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) 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) 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 @abstractmethod def route( self, rule: str, method: Any, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, ): raise NotImplementedError() def get(self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = 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) def post(self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = 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) def put(self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = 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) def delete( self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = 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) def patch( self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = 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) 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 : dict
var current_event : BaseProxyEvent
var lambda_context : LambdaContext
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)
-
Delete route decorator with DELETE
method
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.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 ): """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)
def get(self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None)
-
Get route decorator with GET
method
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"} @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): """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)
def patch(self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None)
-
Patch route decorator with PATCH
method
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.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 ): """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)
def post(self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None)
-
Post route decorator with POST
method
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.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): """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)
def put(self, rule: str, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None)
-
Put route decorator with PUT
method
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.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): """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)
def route(self, rule: str, method: Any, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None)
-
Expand source code
@abstractmethod def route( self, rule: str, method: Any, cors: Optional[bool] = None, compress: bool = False, cache_control: Optional[str] = None, ): raise NotImplementedError()
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_cors
used the custom provided CORSConfig andwithout_cors
do 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-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
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 headers
Methods
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 ProxyEventType (value, names=None, *, module=None, qualname=None, type=None, start=1)
-
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" LambdaFunctionUrlEvent = "LambdaFunctionUrlEvent"
Ancestors
- enum.Enum
Class variables
var ALBEvent
var APIGatewayProxyEvent
var APIGatewayProxyEventV2
var LambdaFunctionUrlEvent
class Response (status_code: int, content_type: Optional[str] = None, body: Union[str, bytes, ForwardRef(None)] = None, headers: Optional[Dict[str, Union[str, List[str]]]] = None, cookies: Optional[List[Cookie]] = 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_type
value. 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: Union[str, bytes, None] = None, headers: Optional[Dict[str, Union[str, List[str]]]] = None, cookies: Optional[List[Cookie]] = 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 [] if content_type: self.headers.setdefault("Content-Type", content_type)
class ResponseBuilder (response: Response, route: Optional[Route] = None)
-
Internally used Response builder
Expand source code
class ResponseBuilder: """Internally used Response builder""" def __init__(self, response: Response, route: Optional[Route] = None): self.response = response self.route = route def _add_cors(self, event: BaseProxyEvent, 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 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: BaseProxyEvent, 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.route.compress and "gzip" in (event.get_header_value("accept-encoding", "") or ""): self._compress() def build(self, event: BaseProxyEvent, 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), }
Methods
def build(self, event: BaseProxyEvent, 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: BaseProxyEvent, 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, rule: Pattern, func: Callable, cors: bool, compress: bool, cache_control: Optional[str])
-
Internally used Route Configuration
Expand source code
class Route: """Internally used Route Configuration""" def __init__( self, method: str, rule: Pattern, func: Callable, cors: bool, compress: bool, cache_control: Optional[str] ): self.method = method.upper() self.rule = rule self.func = func self.cors = cors self.compress = compress self.cache_control = cache_control
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.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, ): 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) self._routes[(rule, methods, cors, compress, cache_control)] = func return func return register_route
Ancestors
- 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)
-
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, ): 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) self._routes[(rule, methods, cors, compress, cache_control)] = func return func return register_route
Inherited members