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AWSTemplateFormatVersion: '2010-09-09'

Description: >
  amazon-ec2-autoscaling-lifecycle-hook-userdata-windows-example
  
  Sample CloudFormation template that deploys an Auto Scaling Group with Lifecycle Hooks that are managed from User Data. 

Parameters:
  AmiId:
    Description: AMI Id
    Type: 'AWS::SSM::Parameter::Value<AWS::EC2::Image::Id>'
    Default: '/aws/service/ami-windows-latest/Windows_Server-2019-English-Full-Base'
  AutoScalingGroupName:
    Description: TBD
    Type: String
    Default: Example Auto Scaling Group
  AutoScalingGroupMinSize:
    Description: TBD
    Type: Number
    Default: 0
  AutoScalingGroupMaxSize:
    Description: TBD
    Type: Number
    Default: 2
  AutoScalingGroupDesiredCapacity:
    Description: TBD
    Type: Number
    Default: 0
  InstanceType:
    Description: Amazon EC2 Instance Type
    Type: String
    Default: "t2.micro"
  InstanceKeyPair: 
    Description: Amazon EC2 Key Pair
    Type: "AWS::EC2::KeyPair::KeyName"
  LifecycleHookName:
    Description: TBD
    Type: String
    Default: "app-install-hook"
  VpcCIDR: 
      Description: Please enter the IP range (CIDR notation) for this VPC
      Type: String
      Default: 10.192.0.0/16
  AvailabilityZone1CIDR:
      Description: Please enter the IP range (CIDR notation) for the app subnet in the first Availability Zone
      Type: String
      Default: 10.192.10.0/24
  AvailabilityZone2CIDR:
      Description: Please enter the IP range (CIDR notation) for the app subnet in the second Availability Zone
      Type: String
      Default: 10.192.11.0/24
  AvailabilityZone3CIDR:
      Description: Please enter the IP range (CIDR notation) for the app subnet in the third Availability Zone
      Type: String
      Default: 10.192.12.0/24
Metadata: 
  AWS::CloudFormation::Interface: 
    ParameterGroups:
    - 
        Label: 
          default: "VPC Configuration"
        Parameters: 
          - VpcCIDR
          - AvailabilityZone1CIDR
          - AvailabilityZone2CIDR
          - AvailabilityZone3CIDR
    -
      Label:
        default: "Instance Configuration"
      Parameters:
        - AmiId
        - InstanceType
        - InstanceKeyPair 
    -
      Label: 
        default: "Auto Scaling Group Configuration"
      Parameters: 
        - AutoScalingGroupName
        - AutoScalingGroupVpcID
        - AutoScalingGroupSubnetIDs
        - AutoScalingGroupMinSize
        - AutoScalingGroupMaxSize
        - AutoScalingGroupDesiredCapacity
        - LifecycleHookName

Resources:

  # VPC/Networking Resources

  VPC: 
      Type: AWS::EC2::VPC
      Properties:
          CidrBlock: !Ref VpcCIDR
          EnableDnsHostnames: true
          
  InternetGateway:
      Type: AWS::EC2::InternetGateway
          
  InternetGatewayAttachment:
      Type: AWS::EC2::VPCGatewayAttachment
      Properties:
          InternetGatewayId: !Ref InternetGateway
          VpcId: !Ref VPC

  AvailabilityZoneSubnet1: 
      Type: AWS::EC2::Subnet
      Properties:
          VpcId: !Ref VPC
          AvailabilityZone: !Select [ 0, !GetAZs '' ]
          CidrBlock: !Ref AvailabilityZone1CIDR
          MapPublicIpOnLaunch: true

  AvailabilityZoneSubnet2: 
      Type: AWS::EC2::Subnet
      Properties:
          VpcId: !Ref VPC
          AvailabilityZone: !Select [ 1, !GetAZs '' ]
          CidrBlock: !Ref AvailabilityZone2CIDR
          MapPublicIpOnLaunch: true

  AvailabilityZoneSubnet3: 
    Type: AWS::EC2::Subnet
    Properties:
        VpcId: !Ref VPC
        AvailabilityZone: !Select [ 2, !GetAZs '' ]
        CidrBlock: !Ref AvailabilityZone3CIDR
        MapPublicIpOnLaunch: true

  InstanceSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties: 
        VpcId: !Ref VPC
        GroupDescription: Instance Security Group

  RouteTable:
    Type: AWS::EC2::RouteTable
    Properties: 
        VpcId: !Ref VPC

  DefaultPublicRoute: 
      Type: AWS::EC2::Route
      DependsOn: InternetGatewayAttachment
      Properties: 
          RouteTableId: !Ref RouteTable
          DestinationCidrBlock: 0.0.0.0/0
          GatewayId: !Ref InternetGateway

  AvailabilityZoneSubnet1RouteTableAssociation:
      Type: AWS::EC2::SubnetRouteTableAssociation
      Properties:
          RouteTableId: !Ref RouteTable
          SubnetId: !Ref AvailabilityZoneSubnet1

  AvailabilityZoneSubnet2RouteTableAssociation:
      Type: AWS::EC2::SubnetRouteTableAssociation
      Properties:
          RouteTableId: !Ref RouteTable
          SubnetId: !Ref AvailabilityZoneSubnet2

  AvailabilityZoneSubnet3RouteTableAssociation:
      Type: AWS::EC2::SubnetRouteTableAssociation
      Properties:
          RouteTableId: !Ref RouteTable
          SubnetId: !Ref AvailabilityZoneSubnet3          

  # Instance/Auto Scaling Group Resources

  LaunchTemplate:
    Type: AWS::EC2::LaunchTemplate
    Properties:
      LaunchTemplateData:
        ImageId: !Ref AmiId
        InstanceType: !Ref InstanceType
        KeyName: !Ref InstanceKeyPair
        SecurityGroupIds:
          - !Ref InstanceSecurityGroup
        IamInstanceProfile:
          Arn: !GetAtt
            - InstanceProfile
            - Arn
        TagSpecifications:
          - ResourceType: instance
            Tags:
              - Key: Name
                Value: LifecycleHookExampleInstance
        UserData: 
          'Fn::Base64': 
            !Sub 
              - |-
                  <powershell>
                    if ((Get-WindowsFeature Web-Server).InstallState -eq "Installed") {
                      Write-Host "IIS is installed, stopping and starting IIS"
                      try
                      {
                        Start-Process "iisreset.exe" -NoNewWindow -Wait
                        Write-Host "Completing Lifecycle Action with CONTINUE"
                        $INSTANCE = (New-Object System.Net.WebClient).DownloadString("http://169.254.169.254/latest/meta-data/instance-id")
                        Complete-ASLifecycleAction -InstanceId $INSTANCE -LifecycleHookName "${lifecycleHookName}" -AutoScalingGroupName "${autoScalingGroupName}" -LifecycleActionResult CONTINUE
                      }
                      catch
                      {
                        Write-Output "An error occured, Completing Lifecycle Action with ABANDON."
                        $INSTANCE = (New-Object System.Net.WebClient).DownloadString("http://169.254.169.254/latest/meta-data/instance-id")
                        Complete-ASLifecycleAction -InstanceId $INSTANCE -LifecycleHookName "${lifecycleHookName}" -AutoScalingGroupName "${autoScalingGroupName}" -LifecycleActionResult ABANDON
                      }
                    } 
                    else {
                      Write-Host "IIS is not installed, installing, stopping and starting IIS."
                      try
                      {
                        Install-WindowsFeature -name Web-Server -IncludeManagementTools
                        Start-Process "iisreset.exe" -NoNewWindow -Wait
                        Write-Host "Sleeping for 120 Seconds to Simulate IIS Configuration."
                        Start-Sleep -s 120
                        Write-Host "Completing Lifecycle Action with CONTINUE"
                        $INSTANCE = (New-Object System.Net.WebClient).DownloadString("http://169.254.169.254/latest/meta-data/instance-id")
                        Complete-ASLifecycleAction -InstanceId $INSTANCE -LifecycleHookName "${lifecycleHookName}" -AutoScalingGroupName "${autoScalingGroupName}" -LifecycleActionResult CONTINUE
                      }
                      catch
                      {
                        Write-Output "An error occured, Completing Lifecycle Action with ABANDON."
                        $INSTANCE = (New-Object System.Net.WebClient).DownloadString("http://169.254.169.254/latest/meta-data/instance-id")
                        Complete-ASLifecycleAction -InstanceId $INSTANCE -LifecycleHookName "${lifecycleHookName}" -AutoScalingGroupName "${autoScalingGroupName}" -LifecycleActionResult ABANDON
                      }
                    }
                  </powershell>
                  <persist>true</persist>
              - { 
                  autoScalingGroupName: !Ref AutoScalingGroupName,
                  lifecycleHookName: !Ref LifecycleHookName
                }

  InstanceRole:
    Type: "AWS::IAM::Role"
    Properties:
      Policies:
        -
          PolicyName: "CompleteLifecycleActionAllowPolicy"
          PolicyDocument:
            Version: "2012-10-17"
            Statement:
              -
                Effect: "Allow"
                Action: "autoscaling:CompleteLifecycleAction"
                Resource: !Sub "arn:aws:autoscaling:${AWS::Region}:${AWS::AccountId}:autoScalingGroup:*:autoScalingGroupName/${AutoScalingGroupName}"                               
      AssumeRolePolicyDocument: 
        Version: "2012-10-17"
        Statement: 
          - 
            Effect: "Allow"
            Principal: 
              Service: 
                - "ec2.amazonaws.com"
            Action: 
              - "sts:AssumeRole"
      Path: "/"
      ManagedPolicyArns:
              - arn:aws:iam::aws:policy/AmazonSSMManagedInstanceCore
              
  InstanceProfile: 
    Type: "AWS::IAM::InstanceProfile"
    Properties: 
      Path: "/"
      Roles: 
        - 
          Ref: "InstanceRole"

  AutoScalingGroup:    
    Type: AWS::AutoScaling::AutoScalingGroup
    Properties: 
      AutoScalingGroupName: !Ref AutoScalingGroupName
      LaunchTemplate: 
        LaunchTemplateId: !Ref LaunchTemplate
        Version: !GetAtt LaunchTemplate.LatestVersionNumber
      DesiredCapacity: !Ref AutoScalingGroupDesiredCapacity
      MaxSize: !Ref AutoScalingGroupMaxSize
      MinSize: !Ref AutoScalingGroupMinSize
      VPCZoneIdentifier: 
        - !Ref AvailabilityZoneSubnet1
        - !Ref AvailabilityZoneSubnet2
        - !Ref AvailabilityZoneSubnet3

  LifecycleHook:
    Type: AWS::AutoScaling::LifecycleHook
    Properties:
      LifecycleHookName: !Ref LifecycleHookName
      AutoScalingGroupName: !Ref AutoScalingGroup
      DefaultResult: ABANDON
      HeartbeatTimeout: 900
      LifecycleTransition: "autoscaling:EC2_INSTANCE_LAUNCHING"