server.yml

Description: >
  Andrea Limoli / Udagram

Parameters:

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

Resources:

  # ROLES
  # - EC2 can read-only S3 buckets

  ServerRoles:
    Type: AWS::IAM::InstanceProfile
    Properties:
      Roles:
        - UdacityS3ReadOnlyEC2 # Role created via AWS console with policy AmazonS3ReadOnlyAccess

  # SECURITY GROUPS

  LoadBalancerSecurityGroup:
    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

  WebServerSecurityGroup:
    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

  # LAUNCH CONFIGURATION

  WebAppLaunchConfig:
    Type: AWS::AutoScaling::LaunchConfiguration
    Properties:
      UserData:
        Fn::Base64: !Sub |
          #!/bin/bash
          apt-get update -y
          apt-get install apache2 -y
          systemctl start apache2.service
          cd /var/www/html
          rm -f index.html
          echo "It works! Udagram, Udacity" > index.html
      IamInstanceProfile: !Ref ServerRoles
      ImageId: ami-01996625fff6b8fcc # Ubuntu 18.04
      SecurityGroups:
        - Ref: WebServerSecurityGroup
      InstanceType: t3.medium # CPU == 2 vCPUs, RAM >= 4 GB
      BlockDeviceMappings:
        - DeviceName: "/dev/sdk"
          Ebs:
            VolumeSize: '10' # at least 10 GB

  WebAppGroup:
    Type: AWS::AutoScaling::AutoScalingGroup
    Properties:
      VPCZoneIdentifier:
        - Fn::ImportValue:
            !Sub "${EnvironmentName}-PRIV-NETS"
      LaunchConfigurationName:
        Ref: WebAppLaunchConfig
      MinSize: '4'
      MaxSize: '6'
      TargetGroupARNs:
        - Ref: WebAppTargetGroup

  WebAppLB:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties:
      Subnets:
        - Fn::ImportValue: !Sub "${EnvironmentName}-PUB1-SN"
        - Fn::ImportValue: !Sub "${EnvironmentName}-PUB2-SN"
      SecurityGroups:
        - Ref: LoadBalancerSecurityGroup

  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"