4-AutoScaling.yml

Description:  This template crete the autoscaling group

Parameters:
  EnvironmentName:
    Description: An environment name that will be prefixed to resource names
    Type: String
    Default: PROD

# AutoScalling
Resources:
  AppAutoScalingGroup:
    Type: AWS::AutoScaling::AutoScalingGroup
    Properties:
      TargetGroupARNs: 
        - Fn::ImportValue:  AppDefaultTargetGroup
      VPCZoneIdentifier: 
        - Fn::ImportValue:  PrivateSubnet1
        - Fn::ImportValue:  PrivateSubnet2
      LaunchConfigurationName: !Ref LaunchConfig
      MinSize: 1
      MaxSize: 1
      DesiredCapacity: 1
      Tags:
        - Key: Name
          Value: !Sub ${EnvironmentName} APP ECS host
          PropagateAtLaunch: true
    CreationPolicy:
      ResourceSignal:
        Timeout: PT15M
    
    UpdatePolicy:
      AutoScalingRollingUpdate:
        MinInstancesInService: 1
        MaxBatchSize: 1
        PauseTime: PT1M
        SuspendProcesses:
          - HealthCheck
          - ReplaceUnhealthy
          - AZRebalance
          - AlarmNotification
          - ScheduledActions
        WaitOnResourceSignals: true

  AppScaleUpPolicy:
    Type: AWS::AutoScaling::ScalingPolicy
    Properties:
      AdjustmentType: ChangeInCapacity
      AutoScalingGroupName:
        Ref: AppAutoScalingGroup
      Cooldown: '1'
      ScalingAdjustment: '1'

  AppCPUAlarmHigh:
    Type: AWS::CloudWatch::Alarm
    Properties:
      EvaluationPeriods: '1'
      Statistic: Average
      Threshold: '10'
      AlarmDescription: Alarm if CPU too high or metric disappears indicating instance is down
      Period: '60'
      AlarmActions:
      - Ref: AppScaleUpPolicy
      Namespace: AWS/EC2
      Dimensions:
      - Name: AppAutoScalingGroup
        Value:
          Ref: AppAutoScalingGroup
      ComparisonOperator: GreaterThanThreshold
      MetricName: CPUUtilization

  WebAutoScalingGroup:
    Type: AWS::AutoScaling::AutoScalingGroup
    Properties:
      TargetGroupARNs: 
        - Fn::ImportValue:  WebDefaultTargetGroup
      VPCZoneIdentifier: 
        - Fn::ImportValue:  PrivateSubnet1
        - Fn::ImportValue:  PrivateSubnet2
      LaunchConfigurationName: !Ref LaunchConfig
      MinSize: 1
      MaxSize: 1
      DesiredCapacity: 1
      Tags:
        - Key: Name
          Value: !Sub ${EnvironmentName} WEB ECS host
          PropagateAtLaunch: true
    CreationPolicy:
      ResourceSignal:
        Timeout: PT15M
    
    UpdatePolicy:
      AutoScalingRollingUpdate:
        MinInstancesInService: 1
        MaxBatchSize: 1
        PauseTime: PT1M
        SuspendProcesses:
          - HealthCheck
          - ReplaceUnhealthy
          - AZRebalance
          - AlarmNotification
          - ScheduledActions
        WaitOnResourceSignals: true
  WebScaleUpPolicy:
    Type: AWS::AutoScaling::ScalingPolicy
    Properties:
      AdjustmentType: ChangeInCapacity
      AutoScalingGroupName:
        Ref: WebAutoScalingGroup
      Cooldown: '1'
      ScalingAdjustment: '1'

  WebCPUAlarmHigh:
    Type: AWS::CloudWatch::Alarm
    Properties:
      EvaluationPeriods: '1'
      Statistic: Average
      Threshold: '10'
      AlarmDescription: Alarm if CPU too high or metric disappears indicating instance is down
      Period: '60'
      AlarmActions:
      - Ref: WebScaleUpPolicy
      Namespace: AWS/EC2
      Dimensions:
      - Name: WebAutoScalingGroup
        Value:
          Ref: WebAutoScalingGroup
      ComparisonOperator: GreaterThanThreshold
      MetricName: CPUUtilization
  #Launch Config
  LaunchConfig: 
    Type: AWS::AutoScaling::LaunchConfiguration
    Properties: 
      LaunchConfigurationName: AppApplicationServer
      AssociatePublicIpAddress: false
      KeyName: aws_key_pair
      ImageId: ami-048a01c78f7bae4aa
      InstanceMonitoring: false
      InstanceType: t2.nano
      SecurityGroups: 
        - Fn::ImportValue:  AppSecurityGroup
      BlockDeviceMappings: 
        - DeviceName: "/dev/sda1"
          Ebs: 
            VolumeSize: "50"
            VolumeType: "io1"
            Iops: 200
            DeleteOnTermination: "true"

#OutPut
Outputs:
  AppAutoScalingGroup:
      Description: AppAutoScalingGroup
      Value: !Ref AppAutoScalingGroup
  
  WebAutoScalingGroup:
      Description: WebAutoScalingGroup
      Value: !Ref WebAutoScalingGroup