AWSTemplateFormatVersion: '2010-09-09'
Description: Creates an Application Load Balancer, which will front-end an ECS Service
  
Parameters:
  VpcId:
    Type: String

  Subnets:
    Type: List<AWS::EC2::Subnet::Id>


Resources:
  SecurityGroup:
    Type: "AWS::EC2::SecurityGroup"
    Properties:
      GroupDescription: !Sub ${AWS::StackName}-alb
      SecurityGroupIngress:
        - CidrIp: "0.0.0.0/0"
          IpProtocol: "TCP"
          FromPort: 80
          ToPort: 80
      VpcId: !Ref VpcId

  LoadBalancer:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties:
      Subnets: !Ref Subnets
      SecurityGroups:
        - !Ref SecurityGroup

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

  TargetGroup:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    DependsOn: LoadBalancer
    Properties:
      # Name: name of LB 
      VpcId: !Ref VpcId
      Port: 80
      Protocol: HTTP
      Matcher:
        HttpCode: 200-299
      HealthCheckIntervalSeconds: 10
      HealthCheckPath: /
      HealthCheckProtocol: HTTP
      HealthCheckTimeoutSeconds: 5
      HealthyThresholdCount: 2
      TargetGroupAttributes:
        - Key: deregistration_delay.timeout_seconds
          Value: 30

  ListenerRule:
    Type: AWS::ElasticLoadBalancingV2::ListenerRule
    Properties:
      ListenerArn: !Ref LoadBalancerListener
      Priority: 1
      Conditions:
        - Field: path-pattern
          Values:
            - /
      Actions:
        - TargetGroupArn: !Ref TargetGroup
          Type: forward

Outputs:
  TargetGroup:
    Value: !Ref TargetGroup
  ServiceUrl:
    Description: URL of the load balancer for the sample service.
    Value: !Sub http://${LoadBalancer.DNSName}
  CanonicalZone:
    Value: !GetAtt LoadBalancer.CanonicalHostedZoneID
  DNSName:
    Value: !GetAtt LoadBalancer.DNSName
  SecurityGroup:
    Value: !Ref SecurityGroup