service.yaml

Description:
    This is an example of a long-running ECS service that needs to connect to another ECS service (product-service)
    via the load-balanced URL. We use an environment variable to pass the product-service URL to the containers.

Parameters: 

    Cluster:
        Description: Please provide the ECS Cluster ID that this service should run on
        Type: String

    DesiredCount: 
        Description: How many instances of this task should we run across our cluster?
        Type: Number
        Default: 2

    ECSTaskExecutionRole:
        Description: The ECS Task Execution Role
        Type: String

    Listener:
        Description: The Application Load Balancer listener to register with
        Type: String

    Path: 
        Description: The path to register with the Application Load Balancer
        Type: String
        Default: /

    ProductServiceUrl:
        Description: The URL of the Product Service (used to fetch product information)
        Type: String

    SecurityGroup:
        Description: Select the Security Group to use for the ECS cluster hosts
        Type: AWS::EC2::SecurityGroup::Id

    Subnets:
        Description: Choose which subnets this ECS cluster should be deployed to
        Type: List<AWS::EC2::Subnet::Id>

    TaskCpu:
        Default: 256
        Description: How much CPU to give the ECS task, in CPU units (where 1,024 units is 1 CPU) or vCPUs
        Type: Number

    TaskMemory:
        Default: 512
        Description: How much memory to give the ECS task in megabytes
        Type: Number

    VPC:
        Description: The VPC that the ECS cluster is deployed to
        Type: AWS::EC2::VPC::Id
        
Resources:

    Service: 
        Type: AWS::ECS::Service
        DependsOn: ListenerRule
        Properties: 
            Cluster: !Ref Cluster
            DeploymentConfiguration:
                MaximumPercent: 200
                MinimumHealthyPercent: 100
            DesiredCount: !Ref DesiredCount
            LaunchType: FARGATE
            NetworkConfiguration:
                AwsvpcConfiguration:
                    AssignPublicIp: ENABLED
                    SecurityGroups:
                      - !Ref SecurityGroup
                    Subnets:
                      - !Select [ 0, !Ref Subnets ]
                      - !Select [ 1, !Ref Subnets ]
            TaskDefinition: !Ref TaskDefinition
            LoadBalancers: 
                - ContainerName: "website-service"
                  ContainerPort: 8000
                  TargetGroupArn: !Ref TargetGroup

    TaskDefinition:
        Type: AWS::ECS::TaskDefinition
        Properties:
            Family: website-service
            Cpu: !Ref 'TaskCpu'
            Memory: !Ref 'TaskMemory'
            NetworkMode: awsvpc
            RequiresCompatibilities:
              - FARGATE
            ExecutionRoleArn: !Ref ECSTaskExecutionRole
            ContainerDefinitions:
                - Name: website-service
                  Essential: true
                  Image: 275396840892.dkr.ecr.us-east-1.amazonaws.com/ecs-refarch-cloudformation/website-service:1.0.0
                  # CPU and Memory reservations are set to 50% of the default values specified above
                  Cpu: 128
                  Memory: 512
                  MemoryReservation: 256
                  Environment: 
                    - Name: PRODUCT_SERVICE_URL
                      Value: !Ref ProductServiceUrl
                  PortMappings:
                    - ContainerPort: 8000

    CloudWatchLogsGroup:
        Type: AWS::Logs::LogGroup
        Properties: 
            LogGroupName: !Ref AWS::StackName
            RetentionInDays: 365  

    TargetGroup:
        Type: AWS::ElasticLoadBalancingV2::TargetGroup
        Properties:
            VpcId: !Ref VPC
            Port: 80
            Protocol: HTTP
            TargetType: ip
            Matcher: 
                HttpCode: 200-299
            HealthCheckIntervalSeconds: 10
            HealthCheckPath: /
            HealthCheckProtocol: HTTP
            HealthCheckTimeoutSeconds: 5
            HealthyThresholdCount: 2
    
    ListenerRule:
        Type: AWS::ElasticLoadBalancingV2::ListenerRule
        Properties:
            ListenerArn: !Ref Listener
            Priority: 1
            Conditions:
                - Field: path-pattern
                  Values: 
                    - !Ref Path
            Actions:
                - TargetGroupArn: !Ref TargetGroup
                  Type: forward