---
AWSTemplateFormatVersion: 2010-09-09

Parameters:
  LaunchType:
    Type: String
    Default: EC2
  InstanceType:
    Type: String
    Default: t2.medium
  ClusterSize:
    Type: Number
    Default: 2
  Subnets:
    Type: List<AWS::EC2::Subnet::Id>
  VpcId:
    Type: AWS::EC2::VPC::Id
  AMI:
    Type: AWS::SSM::Parameter::Value<AWS::EC2::Image::Id>
    Default: /GAMI/latest
  Key:
    Type: String
    Default: PE-GAMI
Conditions:
  EC2: !Equals [ !Ref LaunchType, "EC2" ]
Resources:
  ECSRole:
    Type: AWS::IAM::Role
    Condition: EC2
    Properties:
      Path: /
      AssumeRolePolicyDocument:
        Statement:
          - Action: sts:AssumeRole
            Effect: Allow
            Principal:
              Service: ec2.amazonaws.com
      ManagedPolicyArns:
        - arn:aws:iam::aws:policy/service-role/AmazonEC2ContainerServiceforEC2Role
  SecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Allow basic access via SSH
      VpcId: !Ref 'VpcId'
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 22
          ToPort: 22
          CidrIp: 172.16.0.0/12
  InstanceProfile:
    Type: AWS::IAM::InstanceProfile
    Condition: EC2
    Properties:
      Path: /
      Roles:
        - !Ref ECSRole
  Cluster:
    Type: AWS::ECS::Cluster
    Properties:
      ClusterName: !Ref AWS::StackName
  AutoScalingGroup:
    Type: AWS::AutoScaling::AutoScalingGroup
    Condition: EC2
    Properties:
      VPCZoneIdentifier: !Ref Subnets
      LaunchConfigurationName: !Ref LaunchConfiguration
      MinSize: !Ref ClusterSize
      MaxSize: !Ref ClusterSize
      DesiredCapacity: !Ref ClusterSize
      Tags:
        - Key: Name
          Value: !Sub ${AWS::StackName} - ECS Host
          PropagateAtLaunch: true
    CreationPolicy:
      ResourceSignal:
        Timeout: PT15M
    UpdatePolicy:
      AutoScalingRollingUpdate:
        MinInstancesInService: 1
        MaxBatchSize: 1
        PauseTime: PT15M
        WaitOnResourceSignals: true
  LaunchConfiguration:
    Type: AWS::AutoScaling::LaunchConfiguration
    Condition: EC2
    Metadata:
      AWS::CloudFormation::Init:
        config:
          commands:
            01_add_instance_to_cluster:
                command: !Sub echo ECS_CLUSTER=${Cluster} > /etc/ecs/ecs.config
          files:
            "/etc/cfn/cfn-hup.conf":
              mode: 000400
              owner: root
              group: root
              content: !Sub |
                [main]
                stack=${AWS::StackId}
                region=${AWS::Region}
            "/etc/cfn/hooks.d/cfn-auto-reloader.conf":
              content: !Sub |
                [cfn-auto-reloader-hook]
                triggers=post.update
                path=Resources.ContainerInstances.Metadata.AWS::CloudFormation::Init
                action=/opt/aws/bin/cfn-init -v --region ${AWS::Region} --stack ${AWS::StackName} --resource LaunchConfiguration
          services:
            sysvinit:
              cfn-hup:
                enabled: true
                ensureRunning: true
                files:
                  - /etc/cfn/cfn-hup.conf
                  - /etc/cfn/hooks.d/cfn-auto-reloader.conf
    Properties:
      ImageId: !Ref AMI
      KeyName: !Ref Key
      InstanceType: !Ref InstanceType
      IamInstanceProfile: !Ref InstanceProfile
      SecurityGroups:
        - !Ref SecurityGroup
      UserData:
        Fn::Base64:
          !Sub |
            #!/bin/bash -v
            ## UserData script for version 1
            yum install aws-cfn-bootstrap -y
            /opt/aws/bin/cfn-init -v -c default -s ${AWS::StackId} -r LaunchConfiguration --region ${AWS::Region}
            # disable docker before installing ECS agent
            amazon-linux-extras disable docker
            amazon-linux-extras install -y ecs
            service docker start
            systemd-run --on-active=20 systemctl enable --now ecs
            ## CloudFormation signal that setup is complete
            /opt/aws/bin/cfn-signal -e 0 --stack ${AWS::StackName} --resource AutoScalingGroup --region ${AWS::Region}
Outputs:
  ClusterName:
      Value: !Ref Cluster