Introduction

Integrating API Gateway with AWS Lambda is a crucial step in developing back-end applications using Python. This integration allows developers to create, deploy, and manage APIs with a fully managed feature set. To automate deployments, we can use AWS SAM (AWS Serverless Application Model) or the Serverless Framework.

API Gateway and AWS Lambda

API Gateway is a service that allows developers to create, publish, maintain, monitor, and secure APIs at any scale. It acts as a "gateway" to applications, allowing users to access the resources they need.

AWS Lambda, on the other hand, is a service that lets you run code without provisioning or managing servers. You can run your code in response to events, such as changes to data in an Amazon S3 bucket or an update to an Amazon DynamoDB table.

AWS SAM (AWS Serverless Application Model)

AWS SAM is a serverless application model that allows developers to define their applications in a simple and concise way. It is an extension to AWS CloudFormation that provides a simplified syntax for expressing AWS Lambda functions, Amazon API Gateway APIs, Amazon DynamoDB tables, and other resources.

Serverless Framework

The Serverless Framework is an open source tool that facilitates the development and deployment of serverless applications. It provides an easy way to define the resources your application needs and group them together into a service. It then automates the deployment of those resources to the cloud.

Integrating API Gateway with AWS Lambda

To integrate API Gateway with AWS Lambda, you need to configure a Lambda function that will be invoked whenever a request is made to your API. You then need to configure API Gateway to forward requests to this Lambda function.

Using AWS SAM

With AWS SAM, you can define your Lambda function and API in a single template file. AWS SAM will then create the necessary resources and configure the integration for you. Here is an example of how you can do this:

Resources:
  MyLambdaFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: index.handler
      Runtime: python3.7
      Events:
        MyApi:
          Type: API
          Properties:
            Path: /myapi
            Method: get

This example defines a Lambda function called "MyLambdaFunction" that is invoked when a GET request is made to "/myapi".

Using Serverless Framework

With the Serverless Framework, you can also define your Lambda function and your API in a single file. Here is an example:

service: my-service

providers:
  name: aws
  runtime: python3.7

functions:
  myFunction:
    handler: handler.myHandler
    events:
      - http:
          path: mypath
          method: get

This example defines a Lambda function called "myFunction" that is invoked when a GET request is made to "/mypath".

Conclusion

Integrating API Gateway with AWS Lambda is an essential part of developing back-end applications using Python. With AWS SAM or the Serverless Framework, you can automate deployments and simplify management of your applications.