cloudformation.yaml

AWSTemplateFormatVersion: 2010-09-09
Description: >-
  AWS CloudFormation sample template that create a single Lambda function
  behind an API Gateway with CORS enabled
Resources:
  HelloLambda:
    Type: 'AWS::Lambda::Function'
    Properties:
      Code:
        ZipFile: !Join 
          - |+

          - - '''use strict'';'
            - ''
            - // Hello Lambda
            - 'exports.handler = (event, context, callback) => {'
            - '  console.log(''Event:'', JSON.stringify(event));'
            - '  const name = event.name || ''Cannot find name from input!'';'
            - '  const response = {message: `${name}!`};'
            - '  callback(null, response);'
            - '};'
      Description: A hello lambda api
      FunctionName: HelloLambda
      Handler: index.handler
      Role: !GetAtt 
        - LambdaExecutionRole
        - Arn
      Runtime: nodejs8.10
  LambdaExecutionRole:
    Type: 'AWS::IAM::Role'
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - lambda.amazonaws.com
            Action:
              - 'sts:AssumeRole'
      ManagedPolicyArns:
        - 'arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole'
  HelloCORSRestApi:
    Type: 'AWS::ApiGateway::RestApi'
    Properties:
      Name: Hello CORS API
      Description: API used for HelloLambda requests
      FailOnWarnings: true
  LambdaPermission:
    Type: 'AWS::Lambda::Permission'
    Properties:
      Action: 'lambda:invokeFunction'
      FunctionName: !GetAtt 
        - HelloLambda
        - Arn
      Principal: apigateway.amazonaws.com
      SourceArn: !Join 
        - ''
        - - 'arn:aws:execute-api:'
          - !Ref 'AWS::Region'
          - ':'
          - !Ref 'AWS::AccountId'
          - ':'
          - !Ref HelloCORSRestApi
          - /*
  ApiGatewayCloudWatchLogsRole:
    Type: 'AWS::IAM::Role'
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - apigateway.amazonaws.com
            Action:
              - 'sts:AssumeRole'
      Policies:
        - PolicyName: ApiGatewayLogsPolicy
          PolicyDocument:
            Version: 2012-10-17
            Statement:
              - Effect: Allow
                Action:
                  - 'logs:CreateLogGroup'
                  - 'logs:CreateLogStream'
                  - 'logs:DescribeLogGroups'
                  - 'logs:DescribeLogStreams'
                  - 'logs:PutLogEvents'
                  - 'logs:GetLogEvents'
                  - 'logs:FilterLogEvents'
                Resource: '*'
  ApiGatewayAccount:
    Type: 'AWS::ApiGateway::Account'
    Properties:
      CloudWatchRoleArn: !GetAtt 
        - ApiGatewayCloudWatchLogsRole
        - Arn
  HelloCORSRestApiStage:
    DependsOn:
      - ApiGatewayAccount
    Type: 'AWS::ApiGateway::Stage'
    Properties:
      DeploymentId: !Ref ApiDeployment
      MethodSettings:
        - DataTraceEnabled: true
          HttpMethod: '*'
          LoggingLevel: INFO
          ResourcePath: /*
      RestApiId: !Ref HelloCORSRestApi
      StageName: Prod
      Variables:
        Tom: Maslen-v4
  ApiDeployment:
    Type: 'AWS::ApiGateway::Deployment'
    DependsOn:
      - HelloCORSRestApiRequestGET
      - HelloCORSRestApiRequestPOST
    Properties:
      RestApiId: !Ref HelloCORSRestApi
      StageName: Dev
  HelloCORSRestApiResource:
    Type: 'AWS::ApiGateway::Resource'
    Properties:
      RestApiId: !Ref HelloCORSRestApi
      ParentId: !GetAtt 
        - HelloCORSRestApi
        - RootResourceId
      PathPart: hello
  HelloCORSRestApiRequestGET:
    DependsOn: LambdaPermission
    Type: 'AWS::ApiGateway::Method'
    Properties:
      AuthorizationType: NONE
      HttpMethod: GET
      Integration:
        Type: AWS
        IntegrationHttpMethod: POST
        Uri: !Join 
          - ''
          - - 'arn:aws:apigateway:'
            - !Ref 'AWS::Region'
            - ':lambda:path/2015-03-31/functions/'
            - !GetAtt 
              - HelloLambda
              - Arn
            - /invocations
        IntegrationResponses:
          - StatusCode: 200
            ResponseParameters:
                method.response.header.Access-Control-Allow-Headers: "'Content-Type,X-Amz-Date,Authorization,X-Api-Key,X-Amz-Security-Token'"
                method.response.header.Access-Control-Allow-Methods: "'GET,POST,PUT,DELETE,OPTIONS'"
                method.response.header.Access-Control-Allow-Origin: "'*'"          
        RequestTemplates:
          application/json: !Join 
            - ''
            - - |
              - |
                {
              - |
                  #foreach($param in $input.params().querystring.keySet())
                  "$param": "$util.escapeJavaScript($input.params().querystring.get($param))" #if($foreach.hasNext),#end
                  #end
              - |
                }
      ResourceId: !Ref HelloCORSRestApiResource
      RestApiId: !Ref HelloCORSRestApi
      MethodResponses:
        - StatusCode: 200
          ResponseParameters:
            method.response.header.Access-Control-Allow-Headers: true
            method.response.header.Access-Control-Allow-Methods: true
            method.response.header.Access-Control-Allow-Origin: true        
  HelloCORSRestApiRequestPOST:
    DependsOn: LambdaPermission
    Type: 'AWS::ApiGateway::Method'
    Properties:
      AuthorizationType: NONE
      HttpMethod: POST
      Integration:
        Type: AWS
        IntegrationHttpMethod: POST
        Uri: !Join 
          - ''
          - - 'arn:aws:apigateway:'
            - !Ref 'AWS::Region'
            - ':lambda:path/2015-03-31/functions/'
            - !GetAtt 
              - HelloLambda
              - Arn
            - /invocations
        IntegrationResponses:
          - StatusCode: 200
            ResponseTemplates:
              application/json: $input.json('$')
            ResponseParameters:
                method.response.header.Access-Control-Allow-Headers: "'Content-Type,X-Amz-Date,Authorization,X-Api-Key,X-Amz-Security-Token'"
                method.response.header.Access-Control-Allow-Methods: "'GET,POST,PUT,DELETE,OPTIONS'"
                method.response.header.Access-Control-Allow-Origin: "'*'"
        RequestTemplates:
          application/json: $input.json('$')
      RequestParameters:
        method.request.querystring.name: false
      ResourceId: !Ref HelloCORSRestApiResource
      RestApiId: !Ref HelloCORSRestApi
      MethodResponses:
        - ResponseParameters:
            method.response.header.Access-Control-Allow-Headers: true
            method.response.header.Access-Control-Allow-Methods: true
            method.response.header.Access-Control-Allow-Origin: true
          StatusCode: '200'
  RestApiCORSOptionMethod:
      Type: "AWS::ApiGateway::Method"
      Properties:
        ResourceId: !Ref HelloCORSRestApiResource
        RestApiId: !Ref HelloCORSRestApi
        AuthorizationType: NONE
        HttpMethod: OPTIONS
        Integration:
          Type: MOCK
          IntegrationResponses:
            - ResponseParameters:
                method.response.header.Access-Control-Allow-Headers: "'Content-Type,X-Amz-Date,Authorization,X-Api-Key,X-Amz-Security-Token'"
                method.response.header.Access-Control-Allow-Methods: "'GET,POST,PUT,DELETE,OPTIONS'"
                method.response.header.Access-Control-Allow-Origin: "'*'"
              ResponseTemplates:
                application/json: ''
              StatusCode: '200'
          PassthroughBehavior: NEVER
          RequestTemplates:
            application/json: '{"statusCode": 200}'
        MethodResponses:
          - ResponseModels:
              application/json: Empty
            ResponseParameters:
              method.response.header.Access-Control-Allow-Headers: true
              method.response.header.Access-Control-Allow-Methods: true
              method.response.header.Access-Control-Allow-Origin: true
            StatusCode: '200'

Outputs:
  RootUrl:
    Description: Root URL of the API gateway
    Value: !Join 
      - ''
      - - 'https://'
        - !Ref HelloCORSRestApi
        - .execute-api.
        - !Ref 'AWS::Region'
        - .amazonaws.com