webapp.yaml

Parameters:
  ProjectName:
    Description: Project Name
    Type: String
    Default: weby
Resources:
  EC2LaunchTemplate:
    Type: AWS::EC2::LaunchTemplate
    Properties:
      LaunchTemplateName: !Sub ${ProjectName}-launchTemp
      VersionDescription: 1
      LaunchTemplateData: 
        ImageId: ami-0574da719dca65348
        InstanceType: t2.micro
        KeyName: udakey
        SecurityGroupIds: 
          - Fn::ImportValue: 
              !Sub ${ProjectName}:WebAppSec
        UserData: 
          Fn::Base64: |
            #!/bin/bash
            sudo apt-get update -y
            sudo apt-get install apache2 -y
            sudo systemctl enable apache2
            sudo systemctl start apache2.service
            cd /var/www/html
            echo "Hello from the other side!" > index.html


  WebAppASG:
    Type: AWS::AutoScaling::AutoScalingGroup
    Properties:
      LaunchTemplate: 
        LaunchTemplateId: !Ref EC2LaunchTemplate
        Version: !GetAtt EC2LaunchTemplate.LatestVersionNumber
      MaxSize: 4
      MinSize: 2
      DesiredCapacity: 2
      VPCZoneIdentifier:
        - Fn::ImportValue: 
            !Sub "${ProjectName}:PrivateSub1" 
        - Fn::ImportValue: 
            !Sub "${ProjectName}:PrivateSub2"
      TargetGroupARNs:
        - !Ref WebAppTargetGroup
      Tags:
        - Key: project
          Value: !Ref ProjectName
          PropagateAtLaunch: True

  LoadBalancer:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties:
      Scheme: internet-facing
      SecurityGroups:
        - Fn::ImportValue:
            !Sub "${ProjectName}:LBSec"
      Type: application
      Subnets:
        - Fn::ImportValue: 
            !Sub "${ProjectName}:PublicSub1"
        - Fn::ImportValue: 
            !Sub "${ProjectName}:PublicSub2"

  ELBListener:
    Type: AWS::ElasticLoadBalancingV2::Listener
    Properties: 
      DefaultActions: 
        - Type: forward
          TargetGroupArn: !Ref WebAppTargetGroup
      LoadBalancerArn: !Ref LoadBalancer
      Port: 80
      Protocol: HTTP

  WebAppTargetGroup:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Properties: 
      HealthCheckEnabled: True
      HealthCheckIntervalSeconds: 30
      HealthCheckPath: /
      HealthCheckPort: 80
      HealthCheckProtocol: HTTP
      HealthCheckTimeoutSeconds: 5
      HealthyThresholdCount: 3
      IpAddressType: ipv4
      Name: webTargetGroup
      Port: 80
      Protocol: HTTP
      TargetType: instance
      UnhealthyThresholdCount: 2
      VpcId: 
        Fn::ImportValue:
          !Sub "${ProjectName}:VPC"

  WebAppScailingPolicy:
    Type: AWS::AutoScaling::ScalingPolicy
    Properties: 
      AutoScalingGroupName: !Ref WebAppASG
        EstimatedInstanceWarmup: 30
      PolicyType: TargetTrackingScaling
      TargetTrackingConfiguration: 
        PredefinedMetricSpecification:
          PredefinedMetricType: ASGAverageCPUUtilization
        TargetValue: 50


Outputs:
  LBURL:
    Description: Loadbalancer DNS name
    Value: !GetAtt LoadBalancer.DNSName
    Export: 
      Name: !Sub "${ProjectName}:LB"