AWSTemplateFormatVersion: "2010-09-09"
Transform: AWS::Serverless-2016-10-31
Description: >
  SAM template to deploy SNS dynamic subscribers

# More info about Globals: https://github.com/awslabs/serverless-application-model/blob/master/docs/globals.rst
Globals:
  Function:
    Timeout: 10

Parameters:
  DynamicSubTopicName:
    Type: String
    Default: SNS-DynamicSubscription-Topic

Resources:

  SNSDynamicSubsTopic:
    Type: AWS::SNS::Topic
    Properties:
      TopicName: !Ref DynamicSubTopicName
      
  

  SQSContainerMappingTable:
    Type: AWS::Serverless::SimpleTable
    Properties:
      TableName: SQSContainerMappping
      PrimaryKey:
        Name: id
        Type: String

  VPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: 10.11.0.0/16
      EnableDnsSupport: true
      EnableDnsHostnames: true
      Tags:
        - Key: Name
          Value: !Join [":", [!Ref "AWS::StackName", "VPC"]]

  InternetGateway:
    Type: AWS::EC2::InternetGateway
    Properties:
      Tags:
        - Key: Name
          Value: !Join [":", [!Ref "AWS::StackName", "InternetGateway"]]

  VPCGatewayAttachment:
    Type: AWS::EC2::VPCGatewayAttachment
    Properties:
      VpcId: !Ref VPC
      InternetGatewayId: !Ref InternetGateway

  RouteTable:
    DependsOn: VPCGatewayAttachment
    Type: AWS::EC2::RouteTable
    Properties:
      VpcId: !Ref VPC
      Tags:
        - Key: Name
          Value: !Join [":", [!Ref "AWS::StackName", "RouteTable"]]

  Route:
    Type: AWS::EC2::Route
    Properties:
      RouteTableId: !Ref RouteTable
      DestinationCidrBlock: 0.0.0.0/0
      GatewayId: !Ref InternetGateway

  PublicSubnet1:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 10.11.0.0/24
      AvailabilityZone: !Select [0, !GetAZs ""]
      Tags:
        - Key: Name
          Value: !Join [":", [!Ref "AWS::StackName", "PublicSubnet1"]]

  PublicSubnet2:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 10.11.1.0/24
      AvailabilityZone: !Select [1, !GetAZs ""]
      Tags:
        - Key: Name
          Value: !Join [":", [!Ref "AWS::StackName", "PublicSubnet2"]]

  PublicSubnet1RouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PublicSubnet1
      RouteTableId: !Ref RouteTable

  PublicSubnet2RouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PublicSubnet2
      RouteTableId: !Ref RouteTable

  SecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Limits security group ingress and egress traffic for the ECS tasks running in AWS Fargate
      VpcId: !Ref VPC
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 80
          ToPort: 80
          CidrIp: 0.0.0.0/0

  ECSTaskExecutionRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Statement:
          - Effect: Allow
            Principal:
              Service: [ecs-tasks.amazonaws.com]
            Action: ["sts:AssumeRole"]
      Path: /
      ManagedPolicyArns:
        - arn:aws:iam::aws:policy/service-role/AmazonECSTaskExecutionRolePolicy

  ECSCluster:
    Type: AWS::ECS::Cluster
    Properties:
      ClusterName: sns-demo-cluster

  SNSDynamicSubscriberECSTaskDefinition:
    Type: AWS::ECS::TaskDefinition
    Properties:
      Family: sns-dynamic-subscriber-task
      Cpu: 512
      Memory: 1024
      NetworkMode: awsvpc
      RequiresCompatibilities:
        - FARGATE
      ExecutionRoleArn: !Ref ECSTaskExecutionRole
      TaskRoleArn: !Ref TaskRole
      ContainerDefinitions:
        - Name: sns-dynamic-subscriber-task
          Cpu: 512
          Memory: 1024
          Image: !Sub "681921237057.dkr.ecr.us-west-2.amazonaws.com/sns-demo/sns-dynamic-subscriber:latest"
          Environment:
            - Name: SERVICE_NAME
              Value: sns-dynamic-subscriber-service

          LogConfiguration:
            LogDriver: awslogs
            Options:
              awslogs-group: !Ref SNSDemoCloudWatchLogsGroup
              awslogs-region: !Ref AWS::Region
              awslogs-stream-prefix: sns-dynamic-subs-service

  SNSDynamicSubscriberECSService:
    Type: AWS::ECS::Service

    Properties:
      ServiceName: sns-dynamic-subscriber-service
      Cluster: !Ref ECSCluster
      LaunchType: FARGATE
      DeploymentConfiguration:
        MaximumPercent: 200
        MinimumHealthyPercent: 100
      DesiredCount: 1
      NetworkConfiguration:
        AwsvpcConfiguration:
          AssignPublicIp: ENABLED # to be able to download images from ECR
          SecurityGroups:
            - !Ref SecurityGroup
          Subnets:
            - !Ref PublicSubnet1
            - !Ref PublicSubnet2
      TaskDefinition: !Ref SNSDynamicSubscriberECSTaskDefinition

  SNSDemoCloudWatchLogsGroup:
    Type: AWS::Logs::LogGroup
    Properties:
      LogGroupName: ecs/sns-demo/sns-dynamic-subscriber
      RetentionInDays: 30

  TaskRole:
    Type: AWS::IAM::Role
    Properties:
      # RoleName: !Join ['', [!Ref ServiceName, TaskRole]]
      AssumeRolePolicyDocument:
        Statement:
          - Effect: Allow
            Principal:
              Service: ecs-tasks.amazonaws.com
            Action: "sts:AssumeRole"
      ManagedPolicyArns:
        - !Ref SQSReadPolicy
        - !Ref DDBReadWritePolicy

  SQSReadPolicy:
    Type: AWS::IAM::ManagedPolicy
    Properties:
      PolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Action:
              - sqs:*
              - ecs:*
            Resource: "*"

  DDBReadWritePolicy:
    Type: AWS::IAM::ManagedPolicy
    Properties:
      PolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Action:
              - dynamodb:PutItem
            Resource: !GetAtt SQSContainerMappingTable.Arn

  # ECS Task running event
  SQSECSConsumerStartRule:
    Type: AWS::Events::Rule
    Properties:
      Name: "TaskRunningRule"
      Description: "ECS rule for ECS Task state running"
      RoleArn: !GetAtt EBRoleToLogs.Arn
      EventPattern:
        source:
          - aws.ecs
        detail-type:
          - "ECS Task State Change"
        detail:
          desiredStatus:
            - "RUNNING"
          lastStatus:  
            - "RUNNING"
            
      State: "ENABLED"
      Targets:
        - Arn:
            Fn::GetAtt:
              - "SNSSQSSubscriptionResource"
              - "Arn"
          Id: "TargetId5"
        - Arn:
            Fn::GetAtt:
              - "ECSCWEventsLogsGroup"
              - "Arn"
          Id: "TargetId6"

  # ECS Task stopped event
  SQSECSConsumerStopRule:
    Type: AWS::Events::Rule
    Properties:
      Name: "TaskSoppedRule"
      Description: "ECS rule for ECS Task state stopped"
      RoleArn: !GetAtt EBRoleToLogs.Arn

      EventPattern:
        source:
          - aws.ecs
        detail-type:
          - "ECS Task State Change"
        detail:
          desiredStatus:
            - "STOPPED"
          lastStatus:  
            - "STOPPED"
 

      State: "ENABLED"
      Targets:
        - Arn:
            Fn::GetAtt:
              - "SNSSQSCleanupResource"
              - "Arn"
          Id: "TargetId7"
        - Arn:
            Fn::GetAtt:
              - "ECSCWEventsLogsGroup"
              - "Arn"
          Id: "TargetId8"

  ECSCWEventsLogsGroup:
    Type: AWS::Logs::LogGroup
    Properties:
      
      RetentionInDays: 30

  SNSSQSSubscriptionResource:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: sns-sqs-subscription-service/
      Handler: app.lambda_handler
      Runtime: python3.8
      Environment:
        Variables:
          SERVICE_NAME: SNS-SQS-SubscriptionService
          SQS_CONTAINER_MAPPING_TABLE: SQSContainerMappping
          TOPIC_NAME: 
            Ref: DynamicSubTopicName
      Policies:
      - Statement:
        - Sid: CreateSNSSubscriptionPolicy
          Effect: "Allow"
          Action:
          - "sns:*"
          - "sqs:*"
          - "dynamodb:*"
          Resource: "*"

  SNSSQSCleanupResource:
    Type: AWS::Serverless::Function
    Properties:

      CodeUri: sns-sqs-cleanup-service/
      Handler: app.lambda_handler
      Runtime: python3.8
      Environment:
        Variables:
          SERVICE_NAME: SNS-SQS-CleanupService
          SQS_CONTAINER_MAPPING_TABLE: SQSContainerMappping
          TOPIC_NAME: 
            Ref: DynamicSubTopicName

      Policies:
      - Statement:
        - Sid: SNSSQSCleanupPolicy
          Effect: "Allow"
          Action:
          - "sns:*"
          - "sqs:*"
          - "dynamodb:*"
          Resource: "*"

  ECSStartEventRulePermissionToInvokeLambda: 
    Type: AWS::Lambda::Permission
    Properties: 
      FunctionName: 
        Ref: "SNSSQSSubscriptionResource"
      Action: "lambda:InvokeFunction"
      Principal: "events.amazonaws.com"
      SourceArn: 
        Fn::GetAtt: 
          - "SQSECSConsumerStartRule"
          - "Arn"  
  ECSStopEventRulePermissionToInvokeLambda: 
    Type: AWS::Lambda::Permission
    Properties: 
      FunctionName: 
        Ref: "SNSSQSCleanupResource"
      Action: "lambda:InvokeFunction"
    
      Principal: "events.amazonaws.com"
      SourceArn: 
        Fn::GetAtt: 
          - "SQSECSConsumerStopRule"
          - "Arn"  

  EBRoleToLogs:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: "2012-10-17"
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - events.amazonaws.com
            Action:
              - 'sts:AssumeRole'
      Policies:
        - PolicyName: "myPolicy"
          PolicyDocument:
            Version: "2012-10-17"
            Statement:
              -
                Effect: "Allow"
                Action:
                  - "logs:CreateLogGroup"
                  - "logs:CreateLogStream"
                  - "logs:PutLogEvents"
                Resource: "arn:aws:logs:*:*:*"
  
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

  SQSContainerMappingTable:
    Description: "Amazon DynamoDB table ARN for SQSContainer mapping table"
    Value: !Ref SQSContainerMappingTable