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Powertools for AWS Lambda (Python) is a developer toolkit to implement Serverless best practices and increase developer velocity.

Tip

Powertools for AWS Lambda (Python) is also available for Java, TypeScript, and .NET

Support this project by becoming a reference customer, sharing your work, or using Layers/SAR

You can choose to support us in three ways:

1) Become a reference customer. This gives us permission to list your company in our documentation.

2) Share your work. Blog posts, video, sample projects you used Powertools!

3) Use Lambda Layers or SAR, if possible. This helps us understand who uses Powertools for AWS Lambda (Python) in a non-intrusive way, and helps us gain future investments for other Powertools for AWS Lambda languages.

When using Layers, you can add Powertools for AWS Lambda (Python) as a dev dependency (or as part of your virtual env) to not impact the development process.

Install

You can install Powertools for AWS Lambda (Python) using one of the following options:

• Lambda Layer (x86_64): arn:aws:lambda:{region}:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
• Lambda Layer (arm64): arn:aws:lambda:{region}:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
• Pip: pip install "aws-lambda-powertools"

Looking for Pip signed releases? Learn more about verifying signed builds

Using Pip? You might need to install additional dependencies.

Tracer, Validation and Parser require additional dependencies. If you prefer to install all of them, use pip install "aws-lambda-powertools[all]".

For example:

• Tracer: pip install "aws-lambda-powertools[tracer]"
• Validation: pip install "aws-lambda-powertools[validation]"
• Parser: pip install "aws-lambda-powertools[parser]"
• Tracer and Parser: pip install "aws-lambda-powertools[tracer,parser]"

Local development

Using Lambda Layer? Simply add "aws-lambda-powertools[all]" as a development dependency.

Powertools for AWS Lambda (Python) relies on the AWS SDK bundled in the Lambda runtime. This helps us achieve an optimal package size and initialization. However, when developing locally, you need to install AWS SDK as a development dependency (not as a production dependency):

• Pip: pip install "aws-lambda-powertools[aws-sdk]"
• Poetry: poetry add "aws-lambda-powertools[aws-sdk]" --group dev
• Pipenv: pipenv install --dev "aws-lambda-powertools[aws-sdk]"

Why is that necessary?

Powertools for AWS Lambda (Python) relies on the AWS SDK being available to use in the target runtime (AWS Lambda).

As a result, it affects your favorite IDE in terms of code auto-completion, or running your tests suite locally with no Lambda emulation such as AWS SAM CLI.

A word about dependency resolution

In this context, [aws-sdk] is an alias to the boto3 package. Due to dependency resolution, it'll either install:

• (A) the SDK version available in Lambda runtime
• (B) a more up-to-date version if another package you use also depends on boto3, for example Powertools for AWS Lambda (Python) Tracer

Lambda Layer

As of now, Container Image deployment (OCI) or inline Lambda functions do not support Lambda Layers.

Lambda Layer is a .zip file archive that can contain additional code, pre-packaged dependencies, data, or configuration files. Layers promote code sharing and separation of responsibilities so that you can iterate faster on writing business logic.

For our Layers, we compile and optimize all dependencies, and remove duplicate dependencies already available in the Lambda runtime to achieve the most optimal size.

You can include Powertools for AWS Lambda (Python) Lambda Layer using AWS Lambda Console, or your preferred deployment framework.

Note: Click to expand and copy any regional Lambda Layer ARN

x86_64arm64

Region	Layer ARN
af-south-1	arn:aws:lambda:af-south-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
ap-east-1	arn:aws:lambda:ap-east-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
ap-northeast-1	arn:aws:lambda:ap-northeast-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
ap-northeast-2	arn:aws:lambda:ap-northeast-2:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
ap-northeast-3	arn:aws:lambda:ap-northeast-3:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
ap-south-1	arn:aws:lambda:ap-south-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
ap-south-2	arn:aws:lambda:ap-south-2:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
ap-southeast-1	arn:aws:lambda:ap-southeast-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
ap-southeast-2	arn:aws:lambda:ap-southeast-2:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
ap-southeast-3	arn:aws:lambda:ap-southeast-3:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
ap-southeast-4	arn:aws:lambda:ap-southeast-4:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
ca-central-1	arn:aws:lambda:ca-central-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
ca-west-1	arn:aws:lambda:ca-west-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
eu-central-1	arn:aws:lambda:eu-central-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
eu-central-2	arn:aws:lambda:eu-central-2:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
eu-north-1	arn:aws:lambda:eu-north-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
eu-south-1	arn:aws:lambda:eu-south-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
eu-south-2	arn:aws:lambda:eu-south-2:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
eu-west-1	arn:aws:lambda:eu-west-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
eu-west-2	arn:aws:lambda:eu-west-2:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
eu-west-3	arn:aws:lambda:eu-west-3:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
il-central-1	arn:aws:lambda:il-central-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
me-central-1	arn:aws:lambda:me-central-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
me-south-1	arn:aws:lambda:me-south-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
sa-east-1	arn:aws:lambda:sa-east-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
us-east-1	arn:aws:lambda:us-east-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
us-east-2	arn:aws:lambda:us-east-2:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
us-west-1	arn:aws:lambda:us-west-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
us-west-2	arn:aws:lambda:us-west-2:017000801446:layer:AWSLambdaPowertoolsPythonV2:60

Region	Layer ARN
af-south-1	arn:aws:lambda:af-south-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
ap-east-1	arn:aws:lambda:ap-east-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
ap-northeast-1	arn:aws:lambda:ap-northeast-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
ap-northeast-2	arn:aws:lambda:ap-northeast-2:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
ap-northeast-3	arn:aws:lambda:ap-northeast-3:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
ap-south-1	arn:aws:lambda:ap-south-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
ap-south-2	arn:aws:lambda:ap-south-2:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
ap-southeast-1	arn:aws:lambda:ap-southeast-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
ap-southeast-2	arn:aws:lambda:ap-southeast-2:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
ap-southeast-3	arn:aws:lambda:ap-southeast-3:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
ca-central-1	arn:aws:lambda:ca-central-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
eu-central-1	arn:aws:lambda:eu-central-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
eu-central-2	arn:aws:lambda:eu-central-2:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
eu-north-1	arn:aws:lambda:eu-north-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
eu-south-1	arn:aws:lambda:eu-south-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
eu-south-2	arn:aws:lambda:eu-south-2:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
eu-west-1	arn:aws:lambda:eu-west-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
eu-west-2	arn:aws:lambda:eu-west-2:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
eu-west-3	arn:aws:lambda:eu-west-3:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
il-central-1	arn:aws:lambda:il-central-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
me-central-1	arn:aws:lambda:me-central-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
me-south-1	arn:aws:lambda:me-south-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
sa-east-1	arn:aws:lambda:sa-east-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
us-east-1	arn:aws:lambda:us-east-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
us-east-2	arn:aws:lambda:us-east-2:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
us-west-1	arn:aws:lambda:us-west-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
us-west-2	arn:aws:lambda:us-west-2:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60

Note: Click to expand and copy code snippets for popular frameworks

x86_64arm64

SAMServerless frameworkCDKTerraformPulumiAmplify

MyLambdaFunction:
    Type: AWS::Serverless::Function
    Properties:
        Layers:
            - !Sub arn:aws:lambda:${AWS::Region}:017000801446:layer:AWSLambdaPowertoolsPythonV2:60

functions:
    hello:
      handler: lambda_function.lambda_handler
      layers:
        - arn:aws:lambda:${aws:region}:017000801446:layer:AWSLambdaPowertoolsPythonV2:60

from aws_cdk import core, aws_lambda

class SampleApp(core.Construct):

    def __init__(self, scope: core.Construct, id_: str, env: core.Environment) -> None:
        super().__init__(scope, id_)

        powertools_layer = aws_lambda.LayerVersion.from_layer_version_arn(
            self,
            id="lambda-powertools",
            layer_version_arn=f"arn:aws:lambda:{env.region}:017000801446:layer:AWSLambdaPowertoolsPythonV2:60"
        )
        aws_lambda.Function(self,
            'sample-app-lambda',
            runtime=aws_lambda.Runtime.PYTHON_3_9,
            layers=[powertools_layer]
            # other props...
        )

terraform {
  required_version = "~> 1.0.5"
  required_providers {
    aws = "~> 3.50.0"
  }
}

provider "aws" {
  region  = "{region}"
}

resource "aws_iam_role" "iam_for_lambda" {
  name = "iam_for_lambda"

  assume_role_policy = <<EOF
    {
      "Version": "2012-10-17",
      "Statement": [
        {
          "Action": "sts:AssumeRole",
          "Principal": {
            "Service": "lambda.amazonaws.com"
          },
          "Effect": "Allow"
        }
      ]
    }
    EOF
  }

resource "aws_lambda_function" "test_lambda" {
  filename      = "lambda_function_payload.zip"
  function_name = "lambda_function_name"
  role          = aws_iam_role.iam_for_lambda.arn
  handler       = "index.test"
  runtime       = "python3.9"
  layers        = ["arn:aws:lambda:{region}:017000801446:layer:AWSLambdaPowertoolsPythonV2:60"]

  source_code_hash = filebase64sha256("lambda_function_payload.zip")
}

import json
import pulumi
import pulumi_aws as aws

role = aws.iam.Role("role",
    assume_role_policy=json.dumps({
    "Version": "2012-10-17",
    "Statement": [
        {
        "Action": "sts:AssumeRole",
        "Principal": {
            "Service": "lambda.amazonaws.com"
        },
        "Effect": "Allow"
        }
    ]
    }),
    managed_policy_arns=[aws.iam.ManagedPolicy.AWS_LAMBDA_BASIC_EXECUTION_ROLE]
)

lambda_function = aws.lambda_.Function("function",
    layers=[pulumi.Output.concat("arn:aws:lambda:",aws.get_region_output().name,":017000801446:layer:AWSLambdaPowertoolsPythonV2:11")],
    tracing_config={
        "mode": "Active"
    },
    runtime=aws.lambda_.Runtime.PYTHON3D9,
    handler="index.handler",
    role=role.arn,
    architectures=["x86_64"],
    code=pulumi.FileArchive("lambda_function_payload.zip")
)

# Create a new one with the layer
❯ amplify add function
? Select which capability you want to add: Lambda function (serverless function)
? Provide an AWS Lambda function name: <NAME-OF-FUNCTION>
? Choose the runtime that you want to use: Python
? Do you want to configure advanced settings? Yes
...
? Do you want to enable Lambda layers for this function? Yes
? Enter up to 5 existing Lambda layer ARNs (comma-separated): arn:aws:lambda:eu-central-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
❯ amplify push -y


# Updating an existing function and add the layer
❯ amplify update function
? Select the Lambda function you want to update test2
General information
- Name: <NAME-OF-FUNCTION>
? Which setting do you want to update? Lambda layers configuration
? Do you want to enable Lambda layers for this function? Yes
? Enter up to 5 existing Lambda layer ARNs (comma-separated): arn:aws:lambda:eu-central-1:017000801446:layer:AWSLambdaPowertoolsPythonV2:60
? Do you want to edit the local lambda function now? No

SAMServerless frameworkCDKTerraformPulumiAmplify

MyLambdaFunction:
    Type: AWS::Serverless::Function
    Properties:
        Architectures: [arm64]
        Layers:
            - !Sub arn:aws:lambda:${AWS::Region}:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60

functions:
    hello:
        handler: lambda_function.lambda_handler
        architecture: arm64
        layers:
        - arn:aws:lambda:${aws:region}:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60

from aws_cdk import core, aws_lambda

class SampleApp(core.Construct):

    def __init__(self, scope: core.Construct, id_: str, env: core.Environment) -> None:
        super().__init__(scope, id_)

        powertools_layer = aws_lambda.LayerVersion.from_layer_version_arn(
            self,
            id="lambda-powertools",
            layer_version_arn=f"arn:aws:lambda:{env.region}:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60"
        )
        aws_lambda.Function(self,
            'sample-app-lambda',
            runtime=aws_lambda.Runtime.PYTHON_3_9,
            architecture=aws_lambda.Architecture.ARM_64,
            layers=[powertools_layer]
            # other props...
        )

terraform {
  required_version = "~> 1.0.5"
  required_providers {
    aws = "~> 3.50.0"
  }
}

provider "aws" {
  region  = "{region}"
}

resource "aws_iam_role" "iam_for_lambda" {
  name = "iam_for_lambda"

  assume_role_policy = <<EOF
    {
      "Version": "2012-10-17",
      "Statement": [
        {
          "Action": "sts:AssumeRole",
          "Principal": {
            "Service": "lambda.amazonaws.com"
          },
          "Effect": "Allow"
        }
      ]
    }
    EOF
  }

resource "aws_lambda_function" "test_lambda" {
  filename      = "lambda_function_payload.zip"
  function_name = "lambda_function_name"
  role          = aws_iam_role.iam_for_lambda.arn
  handler       = "index.test"
  runtime       = "python3.9"
  layers        = ["arn:aws:lambda:{region}:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60"]
  architectures = ["arm64"]

  source_code_hash = filebase64sha256("lambda_function_payload.zip")
}

import json
import pulumi
import pulumi_aws as aws

role = aws.iam.Role("role",
    assume_role_policy=json.dumps({
    "Version": "2012-10-17",
    "Statement": [
        {
        "Action": "sts:AssumeRole",
        "Principal": {
            "Service": "lambda.amazonaws.com"
        },
        "Effect": "Allow"
        }
    ]
    }),
    managed_policy_arns=[aws.iam.ManagedPolicy.AWS_LAMBDA_BASIC_EXECUTION_ROLE]
)

lambda_function = aws.lambda_.Function("function",
    layers=[pulumi.Output.concat("arn:aws:lambda:",aws.get_region_output().name,":017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:11")],
    tracing_config={
        "mode": "Active"
    },
    runtime=aws.lambda_.Runtime.PYTHON3D9,
    handler="index.handler",
    role=role.arn,
    architectures=["arm64"],
    code=pulumi.FileArchive("lambda_function_payload.zip")
)

# Create a new one with the layer
❯ amplify add function
? Select which capability you want to add: Lambda function (serverless function)
? Provide an AWS Lambda function name: <NAME-OF-FUNCTION>
? Choose the runtime that you want to use: Python
? Do you want to configure advanced settings? Yes
...
? Do you want to enable Lambda layers for this function? Yes
? Enter up to 5 existing Lambda layer ARNs (comma-separated): arn:aws:lambda:eu-central-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
❯ amplify push -y


# Updating an existing function and add the layer
❯ amplify update function
? Select the Lambda function you want to update test2
General information
- Name: <NAME-OF-FUNCTION>
? Which setting do you want to update? Lambda layers configuration
? Do you want to enable Lambda layers for this function? Yes
? Enter up to 5 existing Lambda layer ARNs (comma-separated): arn:aws:lambda:eu-central-1:017000801446:layer:AWSLambdaPowertoolsPythonV2-Arm64:60
? Do you want to edit the local lambda function now? No

Want to inspect the contents of the Layer?

Change {region} to your AWS region, e.g. eu-west-1

aws lambda get-layer-version-by-arn --arn arn:aws:lambda:{region}:017000801446:layer:AWSLambdaPowertoolsPythonV2:60 --region {region}

The pre-signed URL to download this Lambda Layer will be within Location key.

SAR

Serverless Application Repository (SAR) App deploys a CloudFormation stack with a copy of our Lambda Layer in your AWS account and region.

Compared with the public Layer ARN option, SAR allows you to choose a semantic version and deploys a Layer in your target account.

App	ARN	Description
aws-lambda-powertools-python-layer	arn:aws:serverlessrepo:eu-west-1:057560766410:applications/aws-lambda-powertools-python-layer	Contains all extra dependencies (e.g: pydantic).
aws-lambda-powertools-python-layer-arm64	arn:aws:serverlessrepo:eu-west-1:057560766410:applications/aws-lambda-powertools-python-layer-arm64	Contains all extra dependencies (e.g: pydantic). For arm64 functions.

Click to expand and copy SAR code snippets for popular frameworks

You can create a shared Lambda Layers stack and make this along with other account level layers stack.

SAMServerless frameworkCDKTerraform

AwsLambdaPowertoolsPythonLayer:
    Type: AWS::Serverless::Application
    Properties:
        Location:
            ApplicationId: arn:aws:serverlessrepo:eu-west-1:057560766410:applications/aws-lambda-powertools-python-layer
            SemanticVersion: 2.0.0 # change to latest semantic version available in SAR

MyLambdaFunction:
    Type: AWS::Serverless::Function
    Properties:
        Layers:
            # fetch Layer ARN from SAR App stack output
            - !GetAtt AwsLambdaPowertoolsPythonLayer.Outputs.LayerVersionArn

functions:
    main:
    handler: lambda_function.lambda_handler
    layers:
        - !GetAtt AwsLambdaPowertoolsPythonLayer.Outputs.LayerVersionArn

resources:
    Transform: AWS::Serverless-2016-10-31
    Resources:****
    AwsLambdaPowertoolsPythonLayer:
        Type: AWS::Serverless::Application
        Properties:
            Location:
                ApplicationId: arn:aws:serverlessrepo:eu-west-1:057560766410:applications/aws-lambda-powertools-python-layer
                # Find latest from github.com/aws-powertools/powertools-lambda-python/releases
                SemanticVersion: 2.0.0

from aws_cdk import core, aws_sam as sam, aws_lambda

POWERTOOLS_BASE_NAME = 'AWSLambdaPowertools'
# Find latest from github.com/aws-powertools/powertools-lambda-python/releases
POWERTOOLS_VER = '2.0.0'
POWERTOOLS_ARN = 'arn:aws:serverlessrepo:eu-west-1:057560766410:applications/aws-lambda-powertools-python-layer'

class SampleApp(core.Construct):

    def __init__(self, scope: core.Construct, id_: str) -> None:
        super().__init__(scope, id_)

        # Launches SAR App as CloudFormation nested stack and return Lambda Layer
        powertools_app = sam.CfnApplication(self,
            f'{POWERTOOLS_BASE_NAME}Application',
            location={
                'applicationId': POWERTOOLS_ARN,
                'semanticVersion': POWERTOOLS_VER
            },
        )

        powertools_layer_arn = powertools_app.get_att("Outputs.LayerVersionArn").to_string()
        powertools_layer_version = aws_lambda.LayerVersion.from_layer_version_arn(self, f'{POWERTOOLS_BASE_NAME}', powertools_layer_arn)

        aws_lambda.Function(self,
            'sample-app-lambda',
            runtime=aws_lambda.Runtime.PYTHON_3_8,
            function_name='sample-lambda',
            code=aws_lambda.Code.asset('./src'),
            handler='app.handler',
            layers: [powertools_layer_version]
        )

Credits to Dani Comnea for providing the Terraform equivalent.

terraform {
  required_version = "~> 0.13"
  required_providers {
    aws = "~> 3.50.0"
  }
}

provider "aws" {
  region  = "us-east-1"
}

resource "aws_serverlessapplicationrepository_cloudformation_stack" "deploy_sar_stack" {
  name = "aws-lambda-powertools-python-layer"

  application_id   = data.aws_serverlessapplicationrepository_application.sar_app.application_id
  semantic_version = data.aws_serverlessapplicationrepository_application.sar_app.semantic_version
  capabilities = [
    "CAPABILITY_IAM",
    "CAPABILITY_NAMED_IAM"
  ]
}

data "aws_serverlessapplicationrepository_application" "sar_app" {
  application_id   = "arn:aws:serverlessrepo:eu-west-1:057560766410:applications/aws-lambda-powertools-python-layer"
  semantic_version = var.aws_powertools_version
}

variable "aws_powertools_version" {
  type        = string
  default     = "2.0.0"
  description = "The Powertools for AWS Lambda (Python) release version"
}

output "deployed_powertools_sar_version" {
  value = data.aws_serverlessapplicationrepository_application.sar_app.semantic_version
}

# Fetch Powertools for AWS Lambda (Python) Layer ARN from deployed SAR App
output "aws_lambda_powertools_layer_arn" {
  value = aws_serverlessapplicationrepository_cloudformation_stack.deploy_sar_stack.outputs.LayerVersionArn
}

Example: Least-privileged IAM permissions to deploy Layer

Credits to mwarkentin for providing the scoped down IAM permissions.

The region and the account id for CloudFormationTransform and GetCfnTemplate are fixed.

template.yml

AWSTemplateFormatVersion: "2010-09-09"
Resources:
    PowertoolsLayerIamRole:
    Type: "AWS::IAM::Role"
    Properties:
        AssumeRolePolicyDocument:
        Version: "2012-10-17"
        Statement:
            - Effect: "Allow"
            Principal:
                Service:
                - "cloudformation.amazonaws.com"
            Action:
                - "sts:AssumeRole"
        Path: "/"
    PowertoolsLayerIamPolicy:
    Type: "AWS::IAM::Policy"
    Properties:
        PolicyName: PowertoolsLambdaLayerPolicy
        PolicyDocument:
        Version: "2012-10-17"
        Statement:
            - Sid: CloudFormationTransform
            Effect: Allow
            Action: cloudformation:CreateChangeSet
            Resource:
                - arn:aws:cloudformation:us-east-1:aws:transform/Serverless-2016-10-31
            - Sid: GetCfnTemplate
            Effect: Allow
            Action:
                - serverlessrepo:CreateCloudFormationTemplate
                - serverlessrepo:GetCloudFormationTemplate
            Resource:
                # this is arn of the Powertools for AWS Lambda (Python) SAR app
                - arn:aws:serverlessrepo:eu-west-1:057560766410:applications/aws-lambda-powertools-python-layer
            - Sid: S3AccessLayer
            Effect: Allow
            Action:
                - s3:GetObject
            Resource:
                # AWS publishes to an external S3 bucket locked down to your account ID
                # The below example is us publishing Powertools for AWS Lambda (Python)
                # Bucket: awsserverlessrepo-changesets-plntc6bfnfj
                # Key: *****/arn:aws:serverlessrepo:eu-west-1:057560766410:applications-aws-lambda-powertools-python-layer-versions-1.10.2/aeeccf50-****-****-****-*********
                - arn:aws:s3:::awsserverlessrepo-changesets-*/*
            - Sid: GetLayerVersion
            Effect: Allow
            Action:
                - lambda:PublishLayerVersion
                - lambda:GetLayerVersion
            Resource:
                - !Sub arn:aws:lambda:${AWS::Region}:${AWS::AccountId}:layer:aws-lambda-powertools-python-layer*
        Roles:
        - Ref: "PowertoolsLayerIamRole"

Click to expand and copy an AWS CLI command to list all versions available in SAR

You can fetch available versions via SAR ListApplicationVersions API:

aws serverlessrepo list-application-versions \
    --application-id arn:aws:serverlessrepo:eu-west-1:057560766410:applications/aws-lambda-powertools-python-layer

Quick getting started

sam init --app-template hello-world-powertools-python --name sam-app --package-type Zip --runtime python3.11 --no-tracing

Features

Core utilities such as Tracing, Logging, Metrics, and Event Handler will be available across all Powertools for AWS Lambda languages. Additional utilities are subjective to each language ecosystem and customer demand.

Utility	Description
Tracing	Decorators and utilities to trace Lambda function handlers, and both synchronous and asynchronous functions
Logger	Structured logging made easier, and decorator to enrich structured logging with key Lambda context details
Metrics	Custom Metrics created asynchronously via CloudWatch Embedded Metric Format (EMF)
Event handler: AppSync	AppSync event handler for Lambda Direct Resolver and Amplify GraphQL Transformer function
Event handler: API Gateway, ALB and Lambda Function URL	Amazon API Gateway REST/HTTP API and ALB event handler for Lambda functions invoked using Proxy integration, and Lambda Function URL
Middleware factory	Decorator factory to create your own middleware to run logic before, and after each Lambda invocation
Parameters	Retrieve parameter values from AWS Systems Manager Parameter Store, AWS Secrets Manager, or Amazon DynamoDB, and cache them for a specific amount of time
Batch processing	Handle partial failures for AWS SQS batch processing
Typing	Static typing classes to speedup development in your IDE
Validation	JSON Schema validator for inbound events and responses
Event source data classes	Data classes describing the schema of common Lambda event triggers
Parser	Data parsing and deep validation using Pydantic
Idempotency	Idempotent Lambda handler
Feature Flags	A simple rule engine to evaluate when one or multiple features should be enabled depending on the input
Streaming	Streams datasets larger than the available memory as streaming data.

Environment variables

Info

Explicit parameters take precedence over environment variables

Environment variable	Description	Utility	Default
POWERTOOLS_SERVICE_NAME	Sets service name used for tracing namespace, metrics dimension and structured logging	All	"service_undefined"
POWERTOOLS_METRICS_NAMESPACE	Sets namespace used for metrics	Metrics	None
POWERTOOLS_TRACE_DISABLED	Explicitly disables tracing	Tracing	false
POWERTOOLS_TRACER_CAPTURE_RESPONSE	Captures Lambda or method return as metadata.	Tracing	true
POWERTOOLS_TRACER_CAPTURE_ERROR	Captures Lambda or method exception as metadata.	Tracing	true
POWERTOOLS_TRACE_MIDDLEWARES	Creates sub-segment for each custom middleware	Middleware factory	false
POWERTOOLS_LOGGER_LOG_EVENT	Logs incoming event	Logging	false
POWERTOOLS_LOGGER_SAMPLE_RATE	Debug log sampling	Logging	0
POWERTOOLS_LOG_DEDUPLICATION_DISABLED	Disables log deduplication filter protection to use Pytest Live Log feature	Logging	false
POWERTOOLS_PARAMETERS_MAX_AGE	Adjust how long values are kept in cache (in seconds)	Parameters	5
POWERTOOLS_PARAMETERS_SSM_DECRYPT	Sets whether to decrypt or not values retrieved from AWS SSM Parameters Store	Parameters	false
POWERTOOLS_DEV	Increases verbosity across utilities	Multiple; see POWERTOOLS_DEV effect below	false
POWERTOOLS_LOG_LEVEL	Sets logging level	Logging	INFO

Optimizing for non-production environments

Whether you're prototyping locally or against a non-production environment, you can use POWERTOOLS_DEV to increase verbosity across multiple utilities.

Info

We will emit a warning when POWERTOOLS_DEV is enabled to help you detect misuse in production environments.

When POWERTOOLS_DEV is set to a truthy value (1, true), it'll have the following effects:

Utility	Effect
Logger	Increase JSON indentation to 4. This will ease local debugging when running functions locally under emulators or direct calls while not affecting unit tests
Event Handler	Enable full traceback errors in the response, indent request/responses, and CORS in dev mode (*).
Tracer	Future-proof safety to disables tracing operations in non-Lambda environments. This already happens automatically in the Tracer utility.

Debug mode

As a best practice for libraries, Powertools module logging statements are suppressed.

When necessary, you can use POWERTOOLS_DEBUG environment variable to enable debugging. This will provide additional information on every internal operation.

How to support Powertools for AWS Lambda (Python)?

Becoming a reference customer

Knowing which companies are using this library is important to help prioritize the project internally. If your company is using Powertools for AWS Lambda (Python), you can request to have your name and logo added to the README file by raising a Support Powertools for AWS Lambda (Python) (become a reference) issue.

The following companies, among others, use Powertools:

• Capital One
• CPQi (Exadel Financial Services)
• CloudZero
• CyberArk
• globaldatanet
• IMS
• Jit Security
• Propellor.ai
• TopSport
• Transformity
• Trek10
• Vertex Pharmaceuticals

Sharing your work

Share what you did with Powertools for AWS Lambda (Python) 💞💞. Blog post, workshops, presentation, sample apps and others. Check out what the community has already shared about Powertools for AWS Lambda (Python) here.

Using Lambda Layer or SAR

This helps us understand who uses Powertools for AWS Lambda (Python) in a non-intrusive way, and helps us gain future investments for other Powertools for AWS Lambda languages. When using Layers, you can add Powertools for AWS Lambda (Python) as a dev dependency (or as part of your virtual env) to not impact the development process.

Tenets

These are our core principles to guide our decision making.

• AWS Lambda only. We optimise for AWS Lambda function environments and supported runtimes only. Utilities might work with web frameworks and non-Lambda environments, though they are not officially supported.
• Eases the adoption of best practices. The main priority of the utilities is to facilitate best practices adoption, as defined in the AWS Well-Architected Serverless Lens; all other functionality is optional.
• Keep it lean. Additional dependencies are carefully considered for security and ease of maintenance, and prevent negatively impacting startup time.
• We strive for backwards compatibility. New features and changes should keep backwards compatibility. If a breaking change cannot be avoided, the deprecation and migration process should be clearly defined.
• We work backwards from the community. We aim to strike a balance of what would work best for 80% of customers. Emerging practices are considered and discussed via Requests for Comment (RFCs)
• Progressive. Utilities are designed to be incrementally adoptable for customers at any stage of their Serverless journey. They follow language idioms and their community’s common practices.

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Last update: 2024-01-19