CloudFormation template for ECS

ecs.yaml

# This template defines our ECS cluster and its desired size.
# The Launch Configuration defines how each new instance in our cluster should be bootstrapped
# through its User Data
# The Metadata object gets EC2 instances to register in the ECS cluster
ECSCluster:
    Type: AWS::ECS::Cluster
    Properties:
        ClusterName: !Ref EnvironmentName

ECSAutoScalingGroup:
    Type: AWS::AutoScaling::AutoScalingGroup
    Properties:
        VPCZoneIdentifier: !Ref PrivateSubnets
        LaunchConfigurationName: !Ref ECSLaunchConfiguration
        MinSize: !Ref ClusterSize
        MaxSize: !Ref ClusterSize
        DesiredCapacity: !Ref ClusterSize
        Tags:
            - Key: Name
              Value: !Sub ${EnvironmentName} ECS host
              PropagateAtLaunch: true
    CreationPolicy:
        ResourceSignal:
            Timeout: PT15M
    UpdatePolicy:
        AutoScalingReplacingUpdate:
            WillReplace: true
        AutoScalingRollingUpdate:
            MinInstancesInService: 1
            MaxBatchSize: 1
            PauseTime: PT15M
            SuspendProcesses:
              - HealthCheck
              - ReplaceUnhealthy
              - AZRebalance
              - AlarmNotification
              - ScheduledActions
            WaitOnResourceSignals: true

ECSLaunchConfiguration:
    Type: AWS::AutoScaling::LaunchConfiguration
    Properties:
        ImageId:  !FindInMap [AWSRegionToAMI, !Ref "AWS::Region", AMI]
        InstanceType: !Ref InstanceType
        SecurityGroups:
            - !Ref ECSSecurityGroup
        IamInstanceProfile: !Ref ECSInstanceProfile
        KeyName: laravelaws
        UserData: 
            "Fn::Base64": !Sub |
                #!/bin/bash
                yum update -y
                yum install -y aws-cfn-bootstrap aws-cli go
                echo '{ "credsStore": "ecr-login" }' > ~/.docker/config.json
                go get -u github.com/awslabs/amazon-ecr-credential-helper/ecr-login/cli/docker-credential-ecr-login
                cd /home/ec2-user/go/src/github.com/awslabs/amazon-ecr-credential-helper/ecr-login/cli/docker-credential-ecr-login
                go build
                export PATH=$PATH:/home/ec2-user/go/bin
                /opt/aws/bin/cfn-init -v --region ${AWS::Region} --stack ${AWS::StackName} --resource ECSLaunchConfiguration
                /opt/aws/bin/cfn-signal -e $? --region ${AWS::Region} --stack ${AWS::StackName} --resource ECSAutoScalingGroup
    Metadata:
        AWS::CloudFormation::Init:
            config:
                commands:
                    01_add_instance_to_cluster:
                        command: !Sub echo ECS_CLUSTER=${ECSCluster} >> /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.ECSLaunchConfiguration.Metadata.AWS::CloudFormation::Init
                            action=/opt/aws/bin/cfn-init -v --region ${AWS::Region} --stack ${AWS::StackName} --resource ECSLaunchConfiguration
                services: 
                    sysvinit:
                        cfn-hup: 
                            enabled: true
                            ensureRunning: true
                            files: 
                                - /etc/cfn/cfn-hup.conf
                                - /etc/cfn/hooks.d/cfn-auto-reloader.conf