template.yml

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
# https://github.com/aws/serverless-application-model/blob/master/versions/2016-10-31.md

Description: >
  Address API infrastructure. R53, Cert, LambdaFunction, DynamoTable, Scheduled EventRule.

Parameters:
  AppName:
    Type: String
    Default: "AddressPrediction"
  DomainName:
    Type: String
    Default: "address-api.infocruncher.com"
  HostedZoneName:
    Type: String
    Default: "infocruncher.com."
  FunctionName:
    Type: String
    Default: "AddressPredictionInferenceFunction"
  TableName:
    Type: String
    Default: "AddressPredictionInferenceFunctionUsage"

Globals:
  Function:
    Timeout: 25
    MemorySize: 1769  # 1769 = 1 vCPU
    ReservedConcurrentExecutions: 20
    Environment:
      Variables:
        TABLE_NAME: !Ref TableName

Resources:
  InferenceApiCertificate:
    Type: AWS::CertificateManager::Certificate
    Properties:
      DomainName: !Ref DomainName
      ValidationMethod: DNS

  InferenceApi:
    Type: AWS::Serverless::Api
    Properties:
      Name: !Ref DomainName
      StageName: Prod
      TracingEnabled: true
      # EndpointConfiguration: REGIONAL
      Cors:  # https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/sam-property-api-corsconfiguration.html
        AllowMethods: "'POST, GET'"
        AllowHeaders: "'X-Forwarded-For'"
        AllowOrigin: "'*'"
        MaxAge: "'600'"
        # AllowCredentials: true
      Domain:
        DomainName: !Ref DomainName
        CertificateArn: !Ref InferenceApiCertificate
        Route53:
          HostedZoneName: !Ref HostedZoneName
      Tags:
        App: !Ref AppName

  InferenceFunction:
    # https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/sam-resource-function.html
    # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
    Type: AWS::Serverless::Function
    Properties:
      PackageType: Image
      FunctionName: !Ref FunctionName
      Description: !Join
        - ""
        - - "Function for "
          - !Ref DomainName
      Tags:
        App: !Ref AppName
      Policies:
        DynamoDBWritePolicy:
          TableName: !Ref InferenceTable
      Events:
        Inference:
          # https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/sam-property-function-api.html
          # More info about API Event Source: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#api
          Type: Api
          Properties:
            RestApiId: !Ref InferenceApi
            Path: /predict
            Method: post
        ScheduledEvent:
          # https://github.com/aws/serverless-application-model/blob/master/versions/2016-10-31.md#schedule
          # https://docs.aws.amazon.com/AmazonCloudWatch/latest/events/ScheduledEvents.html
          Type: Schedule
          Properties:
            Name: !Join
              - ""
              - - !Ref AppName
                - "ScheduleEvent"
            Schedule: cron(0/15 * * * ? *)  # (0/15 * * * ? *) is every 15 mins.
            Description: !Join
              - ""
              - - !Ref FunctionName
                - "Function Keep Warm Schedule"
            Enabled: True
    Metadata:
      Dockerfile: Dockerfile
      DockerContext: ./app
      DockerTag: python3.7-v1

  InferenceTable:
    # https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/sam-resource-simpletable.html
    Type: AWS::Serverless::SimpleTable
    Properties:
      PrimaryKey:
        Name: requestId
        Type: String
      TableName: !Ref TableName
      Tags:
        App: !Ref AppName

Outputs:
  # ServerlessRestApi is an implicit API created out of Events key under Serverless::Function
  # Find out more about other implicit resources you can reference within SAM
  # https://github.com/awslabs/serverless-application-model/blob/master/docs/internals/generated_resources.rst#api
  InferenceApiUrl:
    Description: "API Gateway endpoint URL for Prod stage for Inference function"
    Value: !Sub "https://${InferenceApi}.execute-api.${AWS::Region}.amazonaws.com/Prod/predict/"
  InferenceApiId:
    Description: 'API Gateway ARN for InferenceApi'
    Value: !Ref InferenceApi
  BasicAWSApiGatewayRootResourceId:
    Description: 'API Gateway RootResourceId for InferenceApi'
    Value: !GetAtt InferenceApi.RootResourceId
  InferenceFunction:
    Description: "Inference Lambda Function ARN"
    Value: !GetAtt InferenceFunction.Arn
  TableName:
    Description: "Dynamo Table ARN"
    Value: !GetAtt InferenceTable.Arn