LoadBalancer.yaml

AWSTemplateFormatVersion: '2010-09-09'
Description: A stack for deploying containerized applications onto a cluster of EC2
             hosts using Elastic Container Service. This stack contains all loadbalancing resources needed. 
Parameters: 
  VPC: 
    Type: String 
    Description: ID of VPC created in VPC stack 
  PublicSubnetOne:
    Type: String 
    Description: ID of the public subnet One 
  PublicSubnetTwo:
    Type: String 
    Description: ID of the public subnet Two
Resources:
  # Load balancers for getting traffic to containers.
  # This sample template creates two load balancers:
  #
  # - One public load balancer, hosted in public subnets that is accessible
  #   to the public, and is intended to route traffic to one or more public
  #   facing services.
  # - One private load balancer, hosted in private subnets, that only
  #   accepts traffic from other containers in the cluster, and is
  #   intended for private services that should not be accessed directly
  #   by the public.

  # A public facing load balancer, this is used for accepting traffic from the public
  # internet and directing it to public facing microservices
  PublicLoadBalancerSG:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Access to the public facing load balancer
      VpcId: !Ref 'VPC'
      SecurityGroupIngress:
          # Allow access to ALB from anywhere on the internet
          - CidrIp: 0.0.0.0/0
            IpProtocol: -1
  PublicLoadBalancer:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties:
      Scheme: internet-facing
      LoadBalancerAttributes:
      - Key: idle_timeout.timeout_seconds
        Value: '30'
      Subnets:
        # The load balancer is placed into the public subnets, so that traffic
        # from the internet can reach the load balancer directly via the internet gateway
        - !Ref PublicSubnetOne
        - !Ref PublicSubnetTwo 
      SecurityGroups: [!Ref 'PublicLoadBalancerSG']
  # A dummy target group is used to setup the ALB to just drop traffic
  # initially, before any real service target groups have been added.
  DummyTargetGroupPublic:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Properties:
      HealthCheckIntervalSeconds: 6
      HealthCheckPath: /
      HealthCheckProtocol: HTTP
      HealthCheckTimeoutSeconds: 5
      HealthyThresholdCount: 2
      Name: jc-targetgroup
      Port: 80
      Protocol: HTTP
      UnhealthyThresholdCount: 2
      VpcId: !Ref 'VPC'
  PublicLoadBalancerListener:
    Type: AWS::ElasticLoadBalancingV2::Listener
    DependsOn:
      - PublicLoadBalancer
    Properties:
      DefaultActions:
        - TargetGroupArn: !Ref 'DummyTargetGroupPublic'
          Type: 'forward'
      LoadBalancerArn: !Ref 'PublicLoadBalancer'
      Port: 80
      Protocol: HTTP
  # This is an IAM role which authorizes ECS to manage resources on your
  # account on your behalf, such as updating your load balancer with the
  # details of where your containers are, so that traffic can reach your
  # containers.
  ECSRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Statement:
        - Effect: Allow
          Principal:
            Service: [ecs.amazonaws.com]
          Action: ['sts:AssumeRole']
      Path: /
      Policies:
      - PolicyName: ecs-service
        PolicyDocument:
          Statement:
          - Effect: Allow
            Action:
              # Rules which allow ECS to attach network interfaces to instances
              # on your behalf in order for awsvpc networking mode to work right
              - 'ec2:AttachNetworkInterface'
              - 'ec2:CreateNetworkInterface'
              - 'ec2:CreateNetworkInterfacePermission'
              - 'ec2:DeleteNetworkInterface'
              - 'ec2:DeleteNetworkInterfacePermission'
              - 'ec2:Describe*'
              - 'ec2:DetachNetworkInterface'

              # Rules which allow ECS to update load balancers on your behalf
              # with the information sabout how to send traffic to your containers
              - 'elasticloadbalancing:DeregisterInstancesFromLoadBalancer'
              - 'elasticloadbalancing:DeregisterTargets'
              - 'elasticloadbalancing:Describe*'
              - 'elasticloadbalancing:RegisterInstancesWithLoadBalancer'
              - 'elasticloadbalancing:RegisterTargets'
            Resource: '*'
Outputs: 
  LoadBalancerSG: 
    Description: ID of the loadBalancer security Group 
    Value: !Ref PublicLoadBalancerSG
  PublicLBListener: 
    Description: ID of the public load balancer listener
    Value: !Ref PublicLoadBalancerListener