AWSTemplateFormatVersion: '2010-09-09'
Description: This template creates an ECS service, which creates a static web-page with the words 'GREEN-SERVICE' on it.
  
Parameters:
  DesiredCount:
    Type: Number
    Default: 1

  TargetGroup:
    Type: String
    Description: The LB Target Group ARN
    
  Cluster:
    Type: String

Resources:
  ECSServiceRole:
    Type: AWS::IAM::Role
    Properties:
      Path: /
      AssumeRolePolicyDocument:
        Statement:
        - Effect: Allow
          Principal:
            Service: [ecs.amazonaws.com]
          Action: ['sts:AssumeRole']
      ManagedPolicyArns:
        - arn:aws:iam::aws:policy/service-role/AmazonEC2ContainerServiceRole

  Service:
    Type: AWS::ECS::Service
    DependsOn: 
      - ECSServiceRole
      - TaskDefinition
    Properties:
      Cluster: !Ref Cluster
      Role: !Ref ECSServiceRole
      DesiredCount: !Ref DesiredCount
      TaskDefinition: !Ref TaskDefinition
#      PlacementStrategies:
#        - Type: spread
#        - Field: host # attribute:ecs.availability-zone
      LoadBalancers:
        - ContainerName: green-app
          ContainerPort: 80
          TargetGroupArn: !Ref TargetGroup

  TaskDefinition:
    Type: AWS::ECS::TaskDefinition
    Properties:
      Volumes:
        - Name: my-vol 
      Family: !Sub ${AWS::StackName}-canary-app
      ContainerDefinitions:
        - Name: green-app
          Cpu: 100
          Memory: 128
          Essential: true
          Image: amazon/amazon-ecs-sample
          EntryPoint:
            - /usr/sbin/apache2 
            - -D
            - FOREGROUND
          MountPoints:
            - SourceVolume: my-vol
              ContainerPath: /var/www/my-vol
          PortMappings:
            - ContainerPort: 80
              HostPort: 0
        - Name: busybox
          Essential: false
          Cpu: 100
          Memory: 128
          Image: busybox
          VolumesFrom:
            - SourceContainer: green-app
          EntryPoint:
            - sh
            - -c
          Command: 
            - /bin/sh -c "echo GREEN-SERVICE > /var/www/my-vol/date"