template.yaml

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: >
  sam-sqs consumer and producer proof of concept

Parameters:
  VpcId:
    Type: String
    Description: "VPC ID"
  LambdaSubnets:
    Description: "Lambda subnets"
    Type: List<AWS::EC2::Subnet::Id>
  DBSecurityGroup:
    Type: String
    Description: "Database security group"
  DBHost:
    Type: String
    Description: "Database host"
  DBPort:
    Type: String
    Description: "Database port"
  DBName:
    Type: String
    NoEcho: true
    Description: "Database name"
  DBUsername:
    Type: String
    NoEcho: true
    Description: "Username for database access"
  DBPassword:
    Type: String
    NoEcho: true
    Description: "Password for database access"

Resources:
  LambdaVPCSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties: 
      GroupName: sqs-consumer-lambda-vpc
      GroupDescription: Security group for SQS consumer lambda function running inside the VPC
      SecurityGroupEgress: 
        - IpProtocol: tcp
          DestinationSecurityGroupId: !Ref DBSecurityGroup
          FromPort: !Ref DBPort
          ToPort: !Ref DBPort
      VpcId: !Ref VpcId
  SQSProducerFunction:
    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
    Properties:
      Description: Lambda function that performs an HTTP request and sends the result to a SQS Queue
      CodeUri: build
      Handler: producer.handler
      Runtime: nodejs14.x
      Events:
        ProductionRequest:
          Type: Api # More info about API Event Source: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#api
          Properties:
            Path: /producer
            Method: post
      Environment:
        Variables:
          QUEUE_NAME: !GetAtt POCQueue.QueueName
          QUEUE_ARN: !GetAtt POCQueue.Arn
      MemorySize: 128
      Timeout: 25
      Policies:
        - AmazonSQSFullAccess 
  # This is an SQS queue with all default configuration properties. To learn more about the available options, see
  # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-sqs-queues.html
  POCQueue:
    Type: AWS::SQS::Queue
    Properties:
      QueueName: poc-queue
  
  # This is the Lambda function definition associated with the source code: sqs-payload-logger.js. For all available properties, see
  # https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
  SQSConsumerFunction:
    Type: AWS::Serverless::Function
    Properties:
      Description: Lambda function that consumes SQS messages and persists them in a database
      Runtime: nodejs14.x
      CodeUri: build
      Handler: consumer.handler
      # This property associates this Lambda function with the SQS queue defined above, so that whenever the queue
      # receives a message, the Lambda function is invoked
      Events:
        SQSQueueEvent:
          Type: SQS
          Properties:
            Queue: !GetAtt POCQueue.Arn
      Environment:
        Variables:
          DB_HOST: !Ref DBHost
          DB_NAME: !Ref DBName
          DB_PORT: !Ref DBPort
          DB_USERNAME: !Ref DBUsername
          DB_PASSWORD: !Ref DBPassword
      ReservedConcurrentExecutions: 2 # limit concurrent executions to not stress db connections
      MemorySize: 128
      Timeout: 25 # Chosen to be less than the default SQS Visibility Timeout of 30 seconds
      Policies:
        - AWSLambdaBasicExecutionRole
        - VPCAccessPolicy: {}
      VpcConfig:
        SecurityGroupIds:
          - !Ref LambdaVPCSecurityGroup
        SubnetIds: !Ref LambdaSubnets

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
  ProducerAPI:
    Description: "API Gateway endpoint URL for Prod stage for Hello World function"
    Value: !Sub "https://${ServerlessRestApi}.execute-api.${AWS::Region}.amazonaws.com/Prod/hello/"
  SQSProducerFunction:
    Description: "SQS Producer Lambda Function ARN"
    Value: !GetAtt SQSProducerFunction.Arn
  SQSProducerFunctionIamRole:
    Description: "Implicit IAM Role created for SQS Producer function"
    Value: !GetAtt SQSProducerFunctionRole.Arn