CloudFormation Stack

dynamicServerlessEnvironmentsStack.yaml

AWSTemplateFormatVersion: 2010-09-09
Parameters:
  stackID:
    Type: String
    AllowedPattern: '^[a-zA-Z0-9-]+$'
  DomainName:
    Type: String
    AllowedPattern: '.*'
  route53HostedZoneId:
    Type: String
    AllowedPattern: '^[a-zA-Z0-9]+[a-zA-Z0-9.]+$'
  CertificateArn:
    Type: String
    AllowedPattern: '^[a-zA-Z0-9]+[a-zA-Z0-9./:-]+$'
Resources:
  apiGateway:
    Type: 'AWS::ApiGateway::RestApi'
    Properties:
      Name: my-api
      Description: My API
      BinaryMediaTypes:
        - '*/*'
  apiGatewayDeployment:
    Type: 'AWS::ApiGateway::Deployment'
    DependsOn:
      - apiGatewayGETMethod
    Properties:
      RestApiId: !Ref apiGateway
      StageName: prod
  lambdaFunction:
    Type: 'AWS::Lambda::Function'
    Properties:
      Code:
        ZipFile: |
          def handler(event,context):
            return {
              'body': 'Hello there {0}'.format(event['requestContext']['identity']['sourceIp']),
              'headers': {
                'Content-Type': 'text/plain'
              },
              'statusCode': 200
            }
      Description: My function
      FunctionName: !Sub '${stackID}'
      Handler: prodserver.handler
      MemorySize: 128
      Role: !GetAtt lambdaIAMRole.Arn
      Runtime: nodejs12.x
      Timeout: 10
      Layers:
        - >-
          arn:aws:lambda:us-east-1:378688096774:layer:kerrpopovich2020-deps-layer:15
  lambdaApiGatewayInvoke:
    Type: 'AWS::Lambda::Permission'
    DependsOn:
      - apiGatewayLambdaResource
    Properties:
      Action: 'lambda:InvokeFunction'
      FunctionName: !GetAtt lambdaFunction.Arn
      Principal: apigateway.amazonaws.com
      SourceArn: !Sub 'arn:aws:execute-api:${AWS::Region}:${AWS::AccountId}:${apiGateway}/*/*/*'
  lambdaIAMRole:
    Type: 'AWS::IAM::Role'
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Action:
              - 'sts:AssumeRole'
            Effect: Allow
            Principal:
              Service:
                - lambda.amazonaws.com
      Policies:
        - PolicyDocument:
            Version: 2012-10-17
            Statement:
              - Action:
                  - 'logs:CreateLogGroup'
                  - 'logs:CreateLogStream'
                  - 'logs:PutLogEvents'
                Effect: Allow
                Resource:
                  - !Sub >-
                    arn:aws:logs:${AWS::Region}:${AWS::AccountId}:log-group:/aws/lambda/${stackID}:*
          PolicyName: lambda
  s3AccessIAMRole:
    Type: 'AWS::IAM::Role'
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Action:
              - 'sts:AssumeRole'
            Effect: Allow
            Principal:
              Service:
                - s3.amazonaws.com
                - apigateway.amazonaws.com
      Policies:
        - PolicyDocument:
            Version: 2012-10-17
            Statement:
              - Effect: Allow
                Action: '*'
                Resource: '*'
          PolicyName: s3
  lambdaLogGroup:
    Type: 'AWS::Logs::LogGroup'
    Properties:
      LogGroupName: !Sub '/aws/lambda/${stackID}'
      RetentionInDays: 90
  apiGatewayGETMethod:
    Type: 'AWS::ApiGateway::Method'
    Properties:
      AuthorizationType: NONE
      HttpMethod: GET
      Integration:
        IntegrationHttpMethod: POST
        Type: AWS_PROXY
        Uri: !Sub 
          - >-
            arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${lambdaArn}/invocations
          - lambdaArn: !GetAtt lambdaFunction.Arn
      ResourceId: !GetAtt apiGateway.RootResourceId
      RestApiId: !Ref apiGateway
  s3Bucket:
    Type: 'AWS::S3::Bucket'
    Properties:
      BucketName: !Ref stackID
  BucketPolicy:
    Type: AWS::S3::BucketPolicy
    Properties:
      PolicyDocument:
        Id: MyS3BucketPolicy
        Version: 2012-10-17
        Statement:
          - Sid: PublicReadForGetBucketObjects
            Effect: Allow
            Principal: '*'
            Action: 's3:GetObject'
            Resource: !Join 
              - ''
              - - 'arn:aws:s3:::'
                - !Ref s3Bucket
                - /*
      Bucket: !Ref s3Bucket
  apiGatewayAssetsResource:
    Type: 'AWS::ApiGateway::Resource'
    Properties:
      RestApiId: !Ref apiGateway
      ParentId: !GetAtt 
        - apiGateway
        - RootResourceId
      PathPart: assets
  apiGatewayAssetsItemsResource:
    Type: 'AWS::ApiGateway::Resource'
    Properties:
      RestApiId: !Ref apiGateway
      PathPart: '{item}'
      ParentId: !Ref apiGatewayAssetsResource
  OptionsMethod:
    Type: AWS::ApiGateway::Method
    Properties:
      AuthorizationType: NONE
      ResourceId: !Ref apiGatewayAssetsItemsResource
      RestApiId: !Ref apiGateway
      HttpMethod: OPTIONS
      Integration:
        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,OPTIONS'"
            method.response.header.Access-Control-Allow-Origin: "'*'"
          ResponseTemplates:
            application/json: ''
        PassthroughBehavior: WHEN_NO_MATCH
        RequestTemplates:
          application/json: '{"statusCode": 200}'
        Type: MOCK
      MethodResponses:
      - StatusCode: 200
        ResponseModels:
          application/json: 'Empty'
        ResponseParameters:
          method.response.header.Access-Control-Allow-Headers: false
          method.response.header.Access-Control-Allow-Methods: false
          method.response.header.Access-Control-Allow-Origin: false
  apiGatewayAssetsItemsResourceMethod:
    Type: 'AWS::ApiGateway::Method'
    Properties:
      ResourceId: !Ref apiGatewayAssetsItemsResource
      RestApiId: !Ref apiGateway
      AuthorizationType: NONE
      HttpMethod: GET
      RequestParameters:
        method.request.path.item: true
      Integration:
        Type: AWS
        Credentials: !GetAtt s3AccessIAMRole.Arn
        IntegrationHttpMethod: GET
        PassthroughBehavior: WHEN_NO_MATCH
        RequestParameters:
          integration.request.path.item: 'method.request.path.item'
        Uri: !Sub >-
          arn:aws:apigateway:${AWS::Region}:s3:path/${stackID}/{item}
        IntegrationResponses:
          - StatusCode: 200
            ResponseTemplates: {"application/json": "", "image/jpg": ""}
      MethodResponses:
        - StatusCode: 200
          ResponseModels: { "application/json": "Empty", "image/jpg": "Empty" }
  apiGatewayLambdaResource:
    Type: 'AWS::ApiGateway::Resource'
    Properties:
      RestApiId: !Ref apiGateway
      PathPart: '{proxy+}'
      ParentId: !GetAtt 
        - apiGateway
        - RootResourceId
  apiGatewayLambdaResourceMethod:
    Type: 'AWS::ApiGateway::Method'
    Properties:
      AuthorizationType: NONE
      RestApiId: !Ref apiGateway
      ResourceId: !Ref apiGatewayLambdaResource
      HttpMethod: ANY
      Integration:
        Type: AWS_PROXY
        IntegrationHttpMethod: POST
        Uri: !Sub 
          - >-
            arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${lambdaArn}/invocations
          - lambdaArn: !GetAtt lambdaFunction.Arn
      MethodResponses:
        - StatusCode: 200
          ResponseModels: { "application/json": "Empty" }
  domainNameResource:
    Type: 'AWS::ApiGateway::DomainName'
    Properties:
      CertificateArn: !Ref CertificateArn
      DomainName: !Ref DomainName
  basePathMapping:
    Type: 'AWS::ApiGateway::BasePathMapping'
    DependsOn:
      - apiGatewayDeployment
    Properties:
      DomainName: !Ref DomainName
      RestApiId: !Ref apiGateway
      Stage: prod
  domainRecordSet:
    Type: 'AWS::Route53::RecordSet'
    Properties:
      AliasTarget:
        DNSName: !GetAtt domainNameResource.DistributionDomainName
        HostedZoneId: !GetAtt domainNameResource.DistributionHostedZoneId
      Type: A
      HostedZoneId: !Ref route53HostedZoneId
      Name: !Ref DomainName
Outputs:
  apiGatewayInvokeURL:
    Value: !Sub >-
      https://${DomainName}
  lambdaArn:
    Value: !GetAtt lambdaFunction.Arn

Making it more flexible so this template can be used for multiple projects. Those previously hard-coded values are now parameters

The tld and subdomain parameters were only used in combination with each other. Replacing them with DomainName makes it possible to now have a url without a subdomain.