AWSTemplateFormatVersion: "2010-09-09"

Description: Sample template describing an example application deployment. (uksb-1q9p31idr)

Parameters:
  AppNameTagValue:
    Description: 'Specify a value for the AppName tag, that will be applied to your infrastructure resources that support tags; minimum length: 3, maximum: 50.'
    Type: String
    Default: AWS CloudFormation Workshop - example app
    MaxLength: 50
    MinLength: 3

  Env:
    Description: The type of environment with which to tag your infrastructure resources that support tags.
    Type: String
    AllowedValues:
      - dev
      - qa
      - prod
    Default: dev

  HostedZoneStackName:
    Description: The name of the CloudFormation stack you created for hosted zone resource(s).
    Type: String
    Default: cloudformation-workshop-dev-hosted-zone
    AllowedPattern: ^[a-zA-Z]{1}[a-zA-Z0-9-]*$
    MaxLength: 128
    MinLength: 1

  InstanceType:
    Description: Amazon EC2 instance type to use for your instances.
    Type: String
    AllowedValues:
      - t2.micro
      - t2.small
      - t2.medium
      - t3.micro
      - t3.small
      - t3.medium
    Default: t2.micro

  LatestAmiId:
    Description: The ID of the region-specific Amazon Machine Image to use.
    Type: AWS::SSM::Parameter::Value<AWS::EC2::Image::Id>
    Default: /aws/service/ami-amazon-linux-latest/amzn2-ami-hvm-x86_64-gp2

  NameTagValue:
    Description: 'Specify a value for the Name tag, that will be applied to your infrastructure resources that support tags; minimum length: 3, maximum: 50.'
    Type: String
    Default: AWS CloudFormation Workshop
    MaxLength: 50
    MinLength: 3

  NetworkStackName:
    Description: The name of the CloudFormation stack you created for network resources.
    Type: String
    Default: cloudformation-workshop-dev-base-network
    AllowedPattern: ^[a-zA-Z]{1}[a-zA-Z0-9-]*$
    MaxLength: 128
    MinLength: 1

  PageTextContent:
    Description: The sample text to show in the HTML page.
    Type: String
    AllowedValues:
      - Hello world!
    Default: Hello world!

  SecurityGroupStackName:
    Description: The name of the CloudFormation stack you created for security group resources.
    Type: String
    Default: cloudformation-workshop-dev-security-groups
    AllowedPattern: ^[a-zA-Z]{1}[a-zA-Z0-9-]*$
    MaxLength: 128
    MinLength: 1

Resources:
  AutoScalingGroup:
    CreationPolicy:
      ResourceSignal:
        Count: 2
        Timeout: PT15M
    UpdatePolicy:
      AutoScalingRollingUpdate:
        MaxBatchSize: 1
        MinInstancesInService: 2
        PauseTime: PT15M
        WaitOnResourceSignals: true
    Type: AWS::AutoScaling::AutoScalingGroup
    Properties:
      DesiredCapacity: 2
      LaunchTemplate:
        LaunchTemplateId: !Ref 'LaunchTemplate'
        Version: !GetAtt LaunchTemplate.LatestVersionNumber
      MaxSize: 4
      MinSize: 2
      Tags:
        - Key: Name
          PropagateAtLaunch: true
          Value: !Ref 'NameTagValue'
        - Key: AppName
          PropagateAtLaunch: true
          Value: !Ref 'AppNameTagValue'
        - Key: Env
          PropagateAtLaunch: true
          Value: !Ref 'Env'
      TargetGroupARNs:
        - !Ref 'TargetGroup'
      VPCZoneIdentifier:
        - !ImportValue
          Fn::Sub: ${NetworkStackName}-PrivateSubnet1Id
        - !ImportValue
          Fn::Sub: ${NetworkStackName}-PrivateSubnet2Id

  HttpListener:
    Type: AWS::ElasticLoadBalancingV2::Listener
    Properties:
      DefaultActions:
        - Order: 1
          TargetGroupArn: !Ref 'TargetGroup'
          Type: forward
      LoadBalancerArn: !Ref 'LoadBalancer'
      Port: 80
      Protocol: HTTP

  LaunchTemplate:
    Type: AWS::EC2::LaunchTemplate
    Metadata:
      AWS::CloudFormation::Init:
        configSets:
          install:
            - install_cfn_hup
            - install_packages
            - configure
        configure:
          files:
            /var/www/html/index.html:
              content: !Sub |
                ${PageTextContent}
              group: root
              mode: "000644"
              owner: root
        install_cfn_hup:
          files:
            /etc/cfn/cfn-hup.conf:
              content: !Sub |
                [main]
                interval=2
                stack=${AWS::StackId}
                region=${AWS::Region}
              group: root
              mode: "000400"
              owner: root
            /etc/cfn/hooks.d/cfn-auto-reloader.conf:
              content: !Sub |
                [cfn-auto-reloader-hook]
                triggers=post.update
                path=Resources.LaunchTemplate.Metadata.AWS::CloudFormation::Init
                action=/opt/aws/bin/cfn-init -v --stack ${AWS::StackName} --resource LaunchTemplate --configsets install --region ${AWS::Region}
              group: root
              mode: "000400"
              owner: root
          services:
            sysvinit:
              cfn-hup:
                enabled: true
                ensureRunning: true
                files:
                  - /etc/cfn/cfn-hup.conf
                  - /etc/cfn/hooks.d/cfn-auto-reloader.conf
        install_packages:
          packages:
            yum:
              httpd: []
          services:
            sysvinit:
              httpd:
                enabled: true
                ensureRunning: true
    Properties:
      LaunchTemplateData:
        ImageId: !Ref 'LatestAmiId'
        InstanceType: !Ref 'InstanceType'
        SecurityGroupIds:
          - !ImportValue
            Fn::Sub: ${SecurityGroupStackName}-AppInstancesSecurityGroupId
        UserData: !Base64
          Fn::Sub: |
            #!/bin/bash
            yum update -y aws-cfn-bootstrap
            /opt/aws/bin/cfn-init -v --stack ${AWS::StackName} --resource LaunchTemplate --configsets install --region ${AWS::Region}
            /opt/aws/bin/cfn-signal -e $? --stack ${AWS::StackName} --resource AutoScalingGroup --region ${AWS::Region}
      TagSpecifications:
        - ResourceType: launch-template
          Tags:
            - Key: Name
              Value: !Ref 'NameTagValue'
            - Key: AppName
              Value: !Ref 'AppNameTagValue'
            - Key: Env
              Value: !Ref 'Env'

  LoadBalancer:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties:
      IpAddressType: ipv4
      Scheme: internet-facing
      SecurityGroups:
        - !ImportValue
          Fn::Sub: ${SecurityGroupStackName}-LoadBalancerSecurityGroupId
      Subnets:
        - !ImportValue
          Fn::Sub: ${NetworkStackName}-PublicSubnet1Id
        - !ImportValue
          Fn::Sub: ${NetworkStackName}-PublicSubnet2Id
      Tags:
        - Key: Name
          Value: !Ref 'NameTagValue'
        - Key: AppName
          Value: !Ref 'AppNameTagValue'
        - Key: Env
          Value: !Ref 'Env'
      Type: application

  RecordSet:
    Type: AWS::Route53::RecordSet
    Properties:
      AliasTarget:
        DNSName: !GetAtt LoadBalancer.DNSName
        EvaluateTargetHealth: true
        HostedZoneId: !GetAtt LoadBalancer.CanonicalHostedZoneID
      HostedZoneId: !ImportValue
        Fn::Sub: ${HostedZoneStackName}-HostedZoneId
      Name: !ImportValue
        Fn::Sub: ${HostedZoneStackName}-HostedZoneName
      Region: !Ref 'AWS::Region'
      SetIdentifier: !ImportValue
        Fn::Sub: ${HostedZoneStackName}-HostedZoneName
      Type: A

  TargetGroup:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Properties:
      HealthCheckIntervalSeconds: 30
      HealthCheckPath: /
      HealthCheckTimeoutSeconds: 5
      HealthyThresholdCount: 5
      Matcher:
        HttpCode: 200
      Port: 80
      Protocol: HTTP
      Tags:
        - Key: Name
          Value: !Ref 'NameTagValue'
        - Key: AppName
          Value: !Ref 'AppNameTagValue'
        - Key: Env
          Value: !Ref 'Env'
      TargetType: instance
      UnhealthyThresholdCount: 2
      VpcId: !ImportValue
        Fn::Sub: ${NetworkStackName}-VpcId

Outputs:
  AppUrl:
    Description: URL of the sample app.
    Value: !Sub 'http://${LoadBalancer.DNSName}'