sam-template.yml

AWSTemplateFormatVersion: 2010-09-09
Transform: AWS::Serverless-2016-10-31
Description: >
  AWS Blueprint for SAM using NestJS and on-demand DynamoDB.  Single lambda serves entire API via proxy+.
  Supports CORS from ALL origins

Parameters:
  StageName:
    Type: String
    Description: The stage name, also the lambda alias
    Default: test
  DDBTableName:
    Type: String
    Description: DDB_TABLENAME env var
    Default: test-SingleTable
  SomeSecretInSSM:
    Type: "AWS::SSM::Parameter::Value<String>"
    Description: The SSM parameter key for some secret value
    Default: /stage/repo_name/branch/envs/SECRET_KEY

# More info about Globals: https://github.com/awslabs/serverless-application-model/blob/master/docs/globals.rst
Globals:
  Function:
    Runtime: nodejs10.x
    AutoPublishAlias: !Ref StageName
    DeploymentPreference:
      Type: AllAtOnce
    Timeout: 30
    MemorySize: 512
  Api: # https://alexharv074.github.io/2019/03/31/introduction-to-sam-part-iii-adding-a-proxy-endpoint-and-cors-configuration.html#cors-configuration
    Cors:
      AllowMethods: "'DELETE,GET,HEAD,OPTIONS,PATCH,POST,PUT'"
      AllowHeaders: "'Content-Type,X-Amz-Date,Authorization,X-Api-Key,X-Amz-Security-Token'"
      AllowOrigin: "'*'"
      MaxAge: "'600'"

    # Logging, Metrics, Throttling, and all other Stage settings
    MethodSettings: [{
        "LoggingLevel": "INFO",
        "MetricsEnabled": True,
        "DataTraceEnabled": True,

        # On all Paths & methods
        "ResourcePath": "/*",
        "HttpMethod": "*",
    }]  

Conditions:   
  NotStaging: !Not [!Equals [ !Ref StageName, staging ]]
  IsLocal: !Equals [ !Ref StageName, local ]
  #If resources are in a seperate file with naming convention [stage]--[repo]--[branch]--[eyecatcher]--r 
  #the following line would exist in said resources file
  #NotStaging: !Not [!Equals [ !Select [ "0", !Split [ '--', !Ref 'AWS::StackName' ] ], staging ]]

Resources:
  APIG:
    Type: AWS::Serverless::Api
    Properties:
      StageName: !Ref StageName
      Variables:
        Stage: !Ref StageName
#TODO: add Tags when supported https://github.com/awslabs/serverless-application-model/issues/384

  DDBTable: 
    Type: AWS::DynamoDB::Table
    # Staging uses prod table, so don't create if staging
    Condition: NotStaging
    Properties: 
      TableName: !Ref DDBTableName
      Tags: 
        - 
          Key: Stage
          Value: !Ref StageName
      BillingMode: PAY_PER_REQUEST
      AttributeDefinitions: 
        - 
          AttributeName: "PK"
          AttributeType: "S"
        - 
          AttributeName: "SK"
          AttributeType: "S"
        - 
          AttributeName: "GSI1PK"
          AttributeType: "S"
        - 
          AttributeName: "GSI1SK"
          AttributeType: "S"          
      KeySchema: 
        - 
          AttributeName: "PK"
          KeyType: "HASH"
        - 
          AttributeName: "SK"
          KeyType: "RANGE"
      GlobalSecondaryIndexes: 
        - 
          IndexName: "GSI1"
          KeySchema: 
            - 
              AttributeName: "GSI1PK"
              KeyType: "HASH"
            - 
              AttributeName: "GSI1SK"
              KeyType: "RANGE"              
          Projection: 
            ProjectionType: "ALL"      

  MonolithicFunction:
    # 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:
      FunctionName: !Sub "${AWS::StackName}--Monolithic"
      Handler: dist/apig-lambda.handler
      # CodeUri is replaced in buildspec.yml during codebuild, to limit zip size
      CodeUri: ./
      Description: !Sub "${StageName}: NestJS API"
      Tags: 
        Stage: !Ref StageName      
      Environment:
        Variables:
          # Keep these in sync with dotenv.example
          APP_STAGE: !Ref StageName
          DDB_TABLENAME: !Ref DDBTableName
          SECRET_KEY: !Ref SomeSecretInSSM
          ENV_TEST: 'hardcoded in sam-template.yml'

      Policies:
        - Version: '2012-10-17'
          Statement:
            - Effect: Allow
              Action:
                - "dynamodb:Batch*"
                - "dynamodb:Describe*"
                - "dynamodb:Get*"
                - "dynamodb:Query"
                - "dynamodb:Scan"
                - "dynamodb:DeleteItem"
                - "dynamodb:UpdateItem"
                - "dynamodb:PutItem"
              Resource: !Sub "arn:aws:dynamodb:*:*:table/${DDBTableName}"
      Events:
        ProxyApiGreedy:
          Type: Api
          Properties:
            RestApiId: !Ref APIG
            Path: /{proxy+}
            Method: ANY

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
  RestApi:
    Description: "API Gateway endpoint URL for Prod stage"
    Value: !Sub "https://${APIG}.execute-api.${AWS::Region}.amazonaws.com/${StageName}/"