Create REST API and its resources

To create a REST API, we need to do the following:

• Create REST API in API Gateway.
• Create Resources in created REST API.
• Configure Lambda Integration.

We can automate all the above things using the below script.

Serverless Config

Write the below content serverless.yml

service: api-gateway-lambda-rest-api

useDotenv: true

provider:
  name: aws
  stage: ${opt:stage, 'dev'}
  region: ap-south-1
  lambdaHashingVersion: 20201221
  logs:
    restApi: true
    level: INFO
  deploymentBucket:
    blockPublicAccess: true
    name: ${self:custom.config.CODE_DEPLOYMENT_BUCKET}
    maxPreviousDeploymentArtifacts: 3

custom:
  config:
    CODE_DEPLOYMENT_BUCKET: ${env:CODE_DEPLOYMENT_BUCKET}
    S3_BUCKET: ${env:S3_BUCKET}

functions:
  myfunction:
    name: ${self:service}-function-${self:provider.stage}
    handler: lambda_function.handler
    description: Sample application with API Gateway integration
    runtime: python3.9
    memorySize: 128
    timeout: 10
    events:
      - http:
          path: api/hello
          method: post
      - http:
          path: api/testApi
          method: get

Provider

In the provider, we configure cloud provider details like cloud provider name, region, logs config, etc.

Custom

In this section (not a default option, we can replace custom with any name) we gonna maintain any configuration variables required for this script.

CODE_DEPLOYMENT_BUCKET 

Cloudformation script generated based on our serverless script and application code (if any) will be stored in this bucket and it will then be used for deployment.

Note: Here we’ll not be creating a new bucket through this script, create an s3 bucket for the deployment bucket, if it does not exist already.

Pre-requisite: AWS

Amazon Web Services is a leading cloud provider which provides us with plenty of Paas, and Iaas, and services that we can use to build and deploy our applications. we going to build and Deploy a REST API with API Gateway which is integrated with AWS Lambda and expose GET and POST methods, here we going to use an open-source framework Serverless for deploying our API.