our_servers.yml

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

  AIMIDtouse:
    Description: Amazon image id to use
    Type: String

  InstanceType:
    Description: This will be replaced by the instance type to use
    Type: String

Resources:
  LBSecGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Allow http to our load balancer
      VpcId:
        Fn::ImportValue:
          !Sub "${EnvironmentName}-VPCID"
      SecurityGroupIngress:
      - IpProtocol: tcp
        FromPort: 80
        ToPort: 80
        CidrIp: 0.0.0.0/0
      SecurityGroupEgress:
      - IpProtocol: tcp
        FromPort: 80
        ToPort: 80
        CidrIp: 0.0.0.0/0
  WebServerSecGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Allow http to our hosts and SSH from local only
      VpcId:
        Fn::ImportValue:
          !Sub "${EnvironmentName}-VPCID"
      SecurityGroupIngress:
      - IpProtocol: tcp
        FromPort: 80
        ToPort: 80
        CidrIp: 0.0.0.0/0
      - IpProtocol: tcp
        FromPort: 22
        ToPort: 22
        CidrIp: 0.0.0.0/0
      SecurityGroupEgress:
      - IpProtocol: tcp
        FromPort: 0
        ToPort: 65535
        CidrIp: 0.0.0.0/0

  WebAppLaunchConfig:
    Type: AWS::AutoScaling::LaunchConfiguration
    Properties:
      UserData:
        Fn::Base64: !Sub |
         #!/bin/bash
         sudo apt-get update -y
         sudo apt-get install apache2 -y
         sudo systemctl start apache2.service
         cd /var/www/html
         echo "it works! Udagram, Udacity" > index.html
      ImageId: !Ref AIMIDtouse
      # Remove keyname for security reasons
      SecurityGroups:
      - Ref: WebServerSecGroup
      InstanceType: !Ref InstanceType
      BlockDeviceMappings:
      - DeviceName: "/dev/sdk"
        Ebs:
          VolumeSize: '10'
  WebAppGroup:
    Type: AWS::AutoScaling::AutoScalingGroup
    Properties:
      VPCZoneIdentifier:
      - Fn::ImportValue: 
          !Sub "${EnvironmentName}-PRIV-NETS"
      LaunchConfigurationName:
        Ref: WebAppLaunchConfig
      MinSize: '3'
      MaxSize: '5'
      TargetGroupARNs:
        - Ref: WebAppTargetGroup

  WebAppLB:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties:
      Subnets:
      - Fn::ImportValue: !Sub "${EnvironmentName}-PUB1-SN"
      - Fn::ImportValue: !Sub "${EnvironmentName}-PUB2-SN"
      SecurityGroups:
      - Ref: LBSecGroup
  Listener:
    Type: AWS::ElasticLoadBalancingV2::Listener
    Properties:
      DefaultActions:
      - Type: forward
        TargetGroupArn:
          Ref: WebAppTargetGroup
      LoadBalancerArn:
        Ref: WebAppLB
      Port: '80'
      Protocol: HTTP
  ALBListenerRule:
      Type: AWS::ElasticLoadBalancingV2::ListenerRule
      Properties:
        Actions:
        - Type: forward
          TargetGroupArn: !Ref 'WebAppTargetGroup'
        Conditions:
        - Field: path-pattern
          Values: [/]
        ListenerArn: !Ref 'Listener'
        Priority: 1
  WebAppTargetGroup:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Properties:
      HealthCheckIntervalSeconds: 10
      HealthCheckPath: /
      HealthCheckProtocol: HTTP
      HealthCheckTimeoutSeconds: 8
      HealthyThresholdCount: 2
      Port: 80
      Protocol: HTTP
      UnhealthyThresholdCount: 5
      VpcId: 
        Fn::ImportValue:
          Fn::Sub: "${EnvironmentName}-VPCID"

Outputs:
  UdacityDns:
    Description: DNS name or Public URL for the Load Balancer
    Value: !Join [ "", [ 'http://', !GetAtt WebAppLB.DNSName ]]
    Export:
      Name: !Sub ${EnvironmentName}-LB-DNSName