AWS Lambda Power Tools

AWS Lambda Powertools Python

AWS Lambda Powertools is great tool! If you haven’t used it yet have a look! serverless-builder integrates with it in few places

Enable it

from serverless.integration.powertools import Powertools

service.enable(Powertools())

Automatically sets ENV variables

It will set POWERTOOLS_SERVICE_NAME and POWERTOOLS_LOGGER_LOG_EVENT ENV variables.

Creates idempotency DynamoDB table

To be able to use idempotency you need to create separated DynamoDB table for your service.

with_idempotency function allows you to create both, dynamodb table, and set correct IAM permissions for it.

You can use it for any lambda function.

# example of use with `http_get`
service.builder.function.http_get(
    "test-list", 
    "List all tests", 
    "/"
).with_idempotency()

It will generate following YAML

service: service-name
provider:
...
  iam:
    role:
      statements:
      - Sid: ServiceNameTestListIdempotencyFullAccess
        Effect: Allow
        Action:
        - dynamodb:BatchGetItem
        - dynamodb:GetItem
        - dynamodb:Query
        - dynamodb:Scan
        - dynamodb:BatchWriteItem
        - dynamodb:DeleteItem
        - dynamodb:UpdateItem
        - dynamodb:PutItem
        Resource:
        - Fn::GetAtt:
          - ServiceNameTestListIdempotency
          - Arn
      name: ${self:service}-${sls:stage}-${aws:region}-service

functions:
  TestList:
    name: service-name-${sls:stage}-test-list
    description: List all tests
    handler: service_name.test-list.handler
    events:
    - http:
        path: /
        method: GET
    environment:
      IDEMPOTENCY_TABLE:
        Ref: ServiceNameTestListIdempotency

resources:
...
    ServiceNameTestListIdempotency:
      Properties:
        TableName: ServiceName${sls:stage}TestListIdempotency
        BillingMode: PAY_PER_REQUEST
        AttributeDefinitions:
        - AttributeName: id
          AttributeType: S
        KeySchema:
        - AttributeName: id
          KeyType: HASH
        TimeToLiveSpecification:
          AttributeName: expiration
          Enabled: true
        PointInTimeRecoverySpecification:
          PointInTimeRecoveryEnabled: true
      Type: AWS::DynamoDB::Table
      DeletionPolicy: Retain

Info: You can use it without enabling integration

Running service.enable(Powertools()) is not required but highly recommended

Warning: You still need to setup your lambda to use idempotency

You still need to follow idempotency configuration for your lambda to use this table