template.yml

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: >
  petit-lambda
  Petit URL Shortener backend for Lambda and API-Gateway
Parameters:
  ServiceBaseUrl:
    Description: Please provide the base url for your URL shortener
    Type: String
    AllowedPattern: ".+"
  NotFoundDestination:
    Description: >-
      Please provide a location to which users will be routed if the shortcode
      does not resolve to an address.
    Type: String
    AllowedPattern: ".+"
  Stage:
    Description: >-
      Please provide the name of the stage to be deployed in API Gateway. This
      could be a version "v1, v1.1, v2" or an environment "test, stage, prod"
      this will be appended to the end of each related resource's name as well.
    Type: String
    Default: "test"
  CrossOriginDomain:
    Description: >-
      Certain API Methods are allowed cross origin access, you can specify domain(s)
      that are allowed. This will default to '*' which will allow any domain.
    Type: String
    Default: "*"
  ApiBaseUrl:
    Description: >-
      Please provide the base url for the API. This may be the URL generated by
      API Gateway for the specified stage, or may be a custom domain. If this is
      not set, or is inaccurate, the "self" links returned in the payload will
      be incorrect.
    Type: String
    Default: "https://APINAME.execute-api.REGION.amazonaws.com/STAGE/"
  ArtifactsBucket:
    Description: >-
      You must provide the bucket name where the petit-api.yml file has been
      uploaded.
    Type: String
    AllowedPattern: ".+"
Resources:
  PetitDatabase:
    Type: AWS::DynamoDB::Table
    Properties:
      Tags:
        -
          Key: "ApplicationName"
          Value: "Petit URL Shortener"
      TableName: !Sub "Petit-${Stage}"
      AttributeDefinitions:
        -
          AttributeName: "shortcode"
          AttributeType: "S"
        -
          AttributeName: "destination"
          AttributeType: "S"
      KeySchema:
        -
          AttributeName: "shortcode"
          KeyType: "HASH"
      ProvisionedThroughput:
        ReadCapacityUnits: 1
        WriteCapacityUnits: 1
      GlobalSecondaryIndexes:
        -
          IndexName: "destinationIndex"
          KeySchema:
            -
              AttributeName: "destination"
              KeyType: "HASH"
          Projection:
              ProjectionType: "ALL"
          ProvisionedThroughput:
            ReadCapacityUnits: 1
            WriteCapacityUnits: 1
  PetitRedirector:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: !Sub "PetitRedirectorFunction-${Stage}"
      Description: >-
        URL shortener function that simply redirects traffic to destinations
        stored in dynamodb.
        (Note: You must connect this to your load balancer manually. SAM does
        not currently provide a way for an application load balancer to be
        specified as an event source.)
      Tags:
        ApplicationName: "Petit URL Shortener"
      CodeUri: "./redirector-app"
      Handler: index.handler
      Runtime: nodejs14.x
      MemorySize: 128
      Timeout: 3
      Policies:
        -
          DynamoDBReadPolicy:
            TableName: !Ref PetitDatabase
      Environment:
        Variables:
          NOT_FOUND_DESTINATION: !Ref NotFoundDestination
          TABLE_NAME: !Ref PetitDatabase
  PetitAPIFunction:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: !Sub "PetitAPIFunction-${Stage}"
      Description: >-
        URL shortener fucntion that provides an API for crud operations
      Tags:
        ApplicationName: "Petit URL Shortener"
      CodeUri: "./"
      Handler: lambda.handler
      Runtime: ruby2.7
      Environment: 
        Variables:
          DB_TABLE_NAME: !Ref PetitDatabase
          SERVICE_BASE_URL: !Ref ServiceBaseUrl
          API_BASE_URL: !Ref ApiBaseUrl
          CROSS_ORIGIN_DOMAIN: !Ref CrossOriginDomain
          APP_ENV: production
      MemorySize: 128
      Timeout: 30
      Policies:
        -
          DynamoDBCrudPolicy:
            TableName: !Ref PetitDatabase
  PetitAPI:
    Type: AWS::Serverless::Api
    Properties:
        Name: PetitAPI
        StageName: !Sub "${Stage}"
        DefinitionBody:
          Fn::Transform:
            Name: AWS::Include
            Parameters:
              Location: !Sub s3://${ArtifactsBucket}/petit-api.yml
        EndpointConfiguration: "EDGE"
  ConfigLambdaPermission:
    Type: "AWS::Lambda::Permission"
    DependsOn:
      - PetitAPIFunction
    Properties:
      Action: lambda:InvokeFunction
      FunctionName: !Ref PetitAPIFunction
      Principal: apigateway.amazonaws.com
Outputs:
   APIEndpoint:
     Description: API Endpoint URL
     Value: !Sub "https://${PetitAPI}.execute-api.${AWS::Region}.amazonaws.com/${Stage}/"