Request validation using serverless framework

Question

I am using serverless framework for the backend. How can I implement request validation? (do not want to write validation inside lambda functions).

Answer 1

Request validation using serverless

plugins:
  - serverless-python-requirements
  - serverless-wsgi
  - serverless-reqvalidator-plugin
  - serverless-aws-documentation
  
provider:
  name: aws
  runtime: python3.8
  region: us-east-1

functions:
  hello:
    handler: handler.hello
    events:
      - http:
          path: /
          method: get
  likes:
    handler: handler.likes
    events:
      - http:
          path: /likes
          method: get
          integration: lambda
          reqValidatorName: xMyRequestValidator
          request:
            passThrough: NEVER
            parameters:
              querystrings:
                userid: true
                activityid: true
            template:
              application/json: '{ "userid":"$input.params(''userid'')","activityid":"$input.params(''activityid'')"}'
          response:
            headers:
              Content-Type: "'application/json'"

custom:
  wsgi:
    app: handler.app
    pythonBin: python # Some systems with Python3 may require this
    packRequirements: false
  pythonRequirements:
    dockerizePip: non-linux
resources:
  Resources:
    xMyRequestValidator:  
      Type: "AWS::ApiGateway::RequestValidator"
      Properties:
        Name: 'my-req-validator'
        RestApiId: 
          Ref: ApiGatewayRestApi
        ValidateRequestBody: true
        ValidateRequestParameters: true