01-demo-internal-alb-asg.yaml

---
AWSTemplateFormatVersion: '2010-09-09'
Description: 'Demo for ELB and Autoscaling'

Parameters:
  Environment:
    Type: String
    Description: Name for this Environment
    Default: DEMO-ELB-ASG-STACK

  KeyName:
    Description: The EC2 Key Pair to allow SSH access to the instances
    Type: AWS::EC2::KeyPair::KeyName
    Default: hasselrot

  InstanceType:
    Description: EC2 instance type for the node instances
    Type: String
    Default: t3.small
    ConstraintDescription: Must be a valid EC2 instance type

  VpcBlock:
    Type: String
    Default: 10.30.0.0/16
    Description: The CIDR range for the VPC. This should be a valid private (RFC 1918) CIDR range.

  Subnet01Block:
    Type: String
    Default: 10.30.1.0/24
    Description: CidrBlock for subnet 01 within the VPC

  Subnet02Block:
    Type: String
    Default: 10.30.2.0/24
    Description: CidrBlock for subnet 02 within the VPC

Metadata:
  AWS::CloudFormation::Interface:
    ParameterGroups:
      -
        Label:
          default: "Worker Network Configuration"
        Parameters:
          - VpcBlock
          - Subnet01Block
          - Subnet02Block
          - Subnet03Block

Resources:
  VPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock:  !Ref VpcBlock
      EnableDnsSupport: true
      EnableDnsHostnames: true
      Tags:
      - Key: Name
        Value: !Sub '${AWS::StackName}-VPC'
      - Key: env
        Value: !Ref Environment

  InternetGateway:
    Type: "AWS::EC2::InternetGateway"
    Properties:
      Tags:
      - Key: env
        Value: !Ref Environment


  VPCGatewayAttachment:
    Type: "AWS::EC2::VPCGatewayAttachment"
    Properties:
      InternetGatewayId: !Ref InternetGateway
      VpcId: !Ref VPC

  PubRouteTable:
    Type: AWS::EC2::RouteTable
    Properties:
      VpcId: !Ref VPC
      Tags:
      - Key: Name
        Value: Public Subnets
      - Key: Network
        Value: Public
      - Key: env
        Value: !Ref Environment

  Route:
    DependsOn: VPCGatewayAttachment
    Type: AWS::EC2::Route
    Properties:
      RouteTableId: !Ref PubRouteTable
      DestinationCidrBlock: 0.0.0.0/0
      GatewayId: !Ref InternetGateway
  
  PubSubnet01:
    Type: AWS::EC2::Subnet
    Metadata:
      Comment: Public Subnet 01
    Properties:
      AvailabilityZone: "eu-west-1a"
      CidrBlock:
        Ref: Subnet01Block
      VpcId:
        Ref: VPC
      MapPublicIpOnLaunch: True
      Tags:
      - Key: Name
        Value: !Sub "${AWS::StackName}-PubSubnet01"
      - Key: env
        Value: !Ref Environment

  Subnet01RouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PubSubnet01
      RouteTableId: !Ref PubRouteTable

  PubSubnet02:
    Type: AWS::EC2::Subnet
    Metadata:
      Comment: Public Subnet 02
    Properties:
      AvailabilityZone: "eu-west-1b"
      CidrBlock:
        Ref: Subnet02Block
      VpcId:
        Ref: VPC
      MapPublicIpOnLaunch: True
      Tags:
      - Key: Name
        Value: !Sub "${AWS::StackName}-PubSubnet02"
      - Key: env
        Value: !Ref Environment

  Subnet02RouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PubSubnet02
      RouteTableId: !Ref PubRouteTable

  SecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Allow node communication
      VpcId: !Ref VPC
      Tags:
      - Key: env
        Value: !Ref Environment
      - Key: Name
        Value: !Sub "${Environment}-SG"

  SecurityGroupWEBIngress:
    Type: AWS::EC2::SecurityGroupIngress
    DependsOn: SecurityGroup
    Properties:
      Description: Allow node communication
      GroupId: !Ref SecurityGroup
      CidrIp: '0.0.0.0/0'
      IpProtocol: 'tcp'
      FromPort: 80
      ToPort: 80

  SecurityGroupSSHIngress:
    Type: AWS::EC2::SecurityGroupIngress
    DependsOn: SecurityGroup
    Properties:
      Description: Allow node communication
      GroupId: !Ref SecurityGroup
      CidrIp: '0.0.0.0/0'
      IpProtocol: 'tcp'
      FromPort: 22
      ToPort: 22

  loadBalancer:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties:
      Scheme: internal
      Subnets:
      - Ref: PubSubnet01
      - Ref: PubSubnet02
      LoadBalancerAttributes:
      - Key: idle_timeout.timeout_seconds
        Value: '50'
      SecurityGroups:
      - Ref: SecurityGroup
      Tags:
      - Key: env
        Value: !Ref Environment
      - Key: Name
        Value: !Sub "${Environment}-ALB"

  TargetGroup:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Properties:
      HealthCheckIntervalSeconds: 5
      HealthCheckProtocol: HTTP
      HealthCheckTimeoutSeconds: 2
      HealthyThresholdCount: 2
      Matcher:
        HttpCode: '200'
      Name: MyTargets
      Port: 80
      Protocol: HTTP
      TargetGroupAttributes:
      - Key: deregistration_delay.timeout_seconds
        Value: '20'
      UnhealthyThresholdCount: 2
      VpcId:
        Ref: VPC

  Listener:
    Type: AWS::ElasticLoadBalancingV2::Listener
    Properties:
      DefaultActions:
      - Type: forward
        TargetGroupArn:
          Ref: TargetGroup
      LoadBalancerArn:
        Ref: loadBalancer
      Port: '80'
      Protocol: HTTP

  NodeGroup:
    Type: AWS::AutoScaling::AutoScalingGroup
    Properties:
      DesiredCapacity: 3
      LaunchConfigurationName: !Ref LaunchConfig
      MinSize: 1
      MaxSize: 3
      TargetGroupARNs: 
      - Ref: "TargetGroup"
      VPCZoneIdentifier:
      - !Ref PubSubnet01
      Tags:
      - Key: Name
        Value: !Sub "${Environment}-Node"
        PropagateAtLaunch: 'true'
      - Key: env
        Value: !Ref Environment
        PropagateAtLaunch: 'true'
    UpdatePolicy:
      AutoScalingRollingUpdate:
        MaxBatchSize: '1'
        MinInstancesInService: 1
        PauseTime: 'PT30S'

  LaunchConfig:
    Type: AWS::AutoScaling::LaunchConfiguration
    Properties:
      ImageId: ami-08935252a36e25f85
      InstanceType: !Ref InstanceType
      KeyName: !Ref KeyName
      SecurityGroups:
      - !Ref SecurityGroup
      BlockDeviceMappings:
        - DeviceName: /dev/xvda
          Ebs:
            VolumeSize: 16
            VolumeType: gp2
            DeleteOnTermination: true
      UserData: 
        Fn::Base64: !Sub |
            #!/bin/bash -xe
            yum update -y
            yum install -y httpd
            echo "Hello World" > /var/www/html/index.html
            service httpd start
            chkconfig httpd on