SNS Fanout in Serverless Framework

.SNS Fanout in Serverless Framework.md

Create a simple SNS Fanout in the Serverless Framework

service1-serverless.yml

org: barstool
app: service1
service: demo

provider:
  name: aws

resources:
  Resources:
    MyOutputTopic:
      Type: 'AWS::SNS::Topic'
      Properties:
        TopicName: MyOutput-${opt:stage}
  Outputs:
    MyOutputTopic:
      Value: !Ref MyOutputTopic
      Export:
        Name: MyOutputTopic-${opt:stage}

service2-serverless.yml

org: barstool
app: service2
service: demo

provider:
  name: aws

resources:
  Resources:
    # Create a basic queue
    Service2Queue:
      Type: 'AWS::SQS::Queue'
      Properties:
        QueueName: Service2-${opt:stage}
        VisibilityTimeout: 60

    # Create an SNS subscription for the queue above
    Service2Subscription:
      Type: 'AWS::SNS::Subscription'
      Properties:
        TopicArn: MyOutputTopic-${opt:stage}
        Endpoint:
          Fn::GetAtt: [Service2Queue, Arn]
        Protocol: sqs
        RawMessageDelivery: 'true'
        
    # Provide the proper permissions for Service2Queue to recieve messages from MyOutputTopic-{$opt:stage}
    Service2QueuePolicy:
      Type: AWS::SQS::QueuePolicy
      Properties:
        PolicyDocument:
          Version: '2012-10-17'
          Statement:
            - Effect: Allow
              Principal: '*'
              Action: SQS:SendMessage
              Resource:
                - Fn::GetAtt: [Service2Queue, Arn]
              Condition:
                ArnEquals:
                  AWS:SourceArn: MyOutputTopic-${opt:stage}
        Queues:
          - !Ref Service2Queue

functions:
  MyOutputTopicQueue:
    handler: handlers/sqs.myOutputTopic
    events:
      - sqs:
          arn:
            Fn::GetAtt: [Service2Queue, Arn]
          batchSize: 10