AWSTemplateFormatVersion: '2010-09-09'
Description: Sets up App Mesh with an ECS-hosted Virtual gateway.

Parameters:
  EnvironmentName:
    Type: String
    Description: "A friendly environment name that will be used for namespacing all cluster resources. Example: staging, qa, or production"
  EnvoyImage:
    Type: String
    Description: Image location for Envoy proxy
    Default: public.ecr.aws/appmesh/aws-appmesh-envoy:v1.18.3.0-prod

Resources:

### Mesh

  Mesh:
    Type: AWS::AppMesh::Mesh
    Properties:
      MeshName: !Ref EnvironmentName
      Spec:
        EgressFilter:
          Type: DROP_ALL


### Virtual gateway for ingress into mesh

  VirtualGateway:
    Type: AWS::AppMesh::VirtualGateway
    Properties:
      MeshName: !GetAtt Mesh.MeshName
      Spec:
        Listeners:
        - PortMapping:
            Port: 9080
            Protocol: http
      VirtualGatewayName: vg-ingress

  IngressTaskIamRole:
    Type: AWS::IAM::Role
    Properties:
      Path: /
      AssumeRolePolicyDocument: |
        {
            "Statement": [{
                "Effect": "Allow",
                "Principal": { "Service": [ "ecs-tasks.amazonaws.com" ]},
                "Action": [ "sts:AssumeRole" ]
            }]
        }
      Policies:
      - PolicyName: ACMExportCertificateAccess
        PolicyDocument: |
          {
            "Statement": [{
              "Effect": "Allow",
              "Action": ["acm:ExportCertificate"],
              "Resource": ["*"]
            }]
          }
      - PolicyName: ACMCertificateAuthorityAccess
        PolicyDocument: |
          {
            "Statement": [{
              "Effect": "Allow",
              "Action": ["acm-pca:GetCertificateAuthorityCertificate"],
              "Resource": ["*"]
            }]
          }
      ManagedPolicyArns:
        - arn:aws:iam::aws:policy/CloudWatchFullAccess
        - arn:aws:iam::aws:policy/AWSXRayDaemonWriteAccess
        - arn:aws:iam::aws:policy/AWSAppMeshPreviewEnvoyAccess
        - arn:aws:iam::aws:policy/AWSAppMeshEnvoyAccess

  IngressServiceDiscoveryRecord:
    Type: 'AWS::ServiceDiscovery::Service'
    Properties:
      Name: "ingress"
      DnsConfig:
        NamespaceId:
          Fn::ImportValue: !Sub "${EnvironmentName}:ServiceDiscoveryNamespaceId"
        DnsRecords:
          - Type: A
            TTL: 300
      HealthCheckCustomConfig:
        FailureThreshold: 1

  IngressTaskDefinition:
    Type: AWS::ECS::TaskDefinition
    Properties:
      RequiresCompatibilities:
        - 'FARGATE'
      Family: !Sub '${EnvironmentName}-Ingress'
      NetworkMode: 'awsvpc'
      Cpu: 256
      Memory: 512
      TaskRoleArn: !Ref IngressTaskIamRole
      ExecutionRoleArn:
        Fn::ImportValue: !Sub "${EnvironmentName}:TaskExecutionRoleArn"
      ContainerDefinitions:
        - Name: 'envoy'
          Image: !Ref EnvoyImage
          Essential: true
          StopTimeout: 5
          Ulimits:
            - Name: "nofile"
              HardLimit: 15000
              SoftLimit: 15000
          PortMappings:
            - ContainerPort: 9901
              Protocol: 'tcp'
            - ContainerPort: 9080
              Protocol: 'tcp'
          HealthCheck:
            Command:
              - 'CMD-SHELL'
              - 'curl -s http://localhost:9901/server_info | grep state | grep -q LIVE'
            Interval: 5
            Timeout: 2
            Retries: 3
            StartPeriod: 60
          LogConfiguration:
            LogDriver: 'awslogs'
            Options:
              awslogs-group:
                Fn::ImportValue: !Sub "${EnvironmentName}:ClusterLogGroup"
              awslogs-region: !Ref AWS::Region
              awslogs-stream-prefix: 'ingress-envoy'
          Environment:
            - Name: 'APPMESH_RESOURCE_ARN'
              Value: !Ref VirtualGateway
            - Name: 'ENABLE_ENVOY_STATS_TAGS'
              Value: '1'
            - Name: 'ENABLE_ENVOY_DOG_STATSD'
              Value: '1'
            - Name: 'STATSD_PORT'
              Value: '8125'
        - Name: 'cw-agent'
          Image: 'amazon/cloudwatch-agent:latest'
          Essential: true
          StopTimeout: 5
          PortMappings:
            - ContainerPort: 8125
              Protocol: 'udp'
          Environment:
            - Name: CW_CONFIG_CONTENT
              Value:
                Fn::Sub:
                  - "{ \"metrics\": { \"namespace\":\"${MetricNamespace}\", \"metrics_collected\": { \"statsd\": { \"metrics_aggregation_interval\": 0}}}}"
                  - MetricNamespace:
                      Fn::Join:
                      - '/'
                      - - !Ref EnvironmentName
                        - gateway-envoy
                        - StatsD
          LogConfiguration:
            LogDriver: 'awslogs'
            Options:
              awslogs-group:
                Fn::ImportValue: !Sub "${EnvironmentName}:ClusterLogGroup"
              awslogs-region: !Ref AWS::Region
              awslogs-stream-prefix: 'ingress-cw-agent'

  IngressService:
    Type: 'AWS::ECS::Service'
    DependsOn:
      - PublicLoadBalancerListener
    Properties:
      Cluster:
        Fn::ImportValue: !Sub "${EnvironmentName}:ClusterName"
      DeploymentConfiguration:
        MaximumPercent: 200
        MinimumHealthyPercent: 100
      DesiredCount: 1
      LaunchType: FARGATE
      ServiceRegistries:
        - RegistryArn:
            'Fn::GetAtt': IngressServiceDiscoveryRecord.Arn
      NetworkConfiguration:
        AwsvpcConfiguration:
          AssignPublicIp: DISABLED
          SecurityGroups:
            - Fn::ImportValue: !Sub "${EnvironmentName}:ContainerSecurityGroup"
          Subnets:
            - Fn::ImportValue: !Sub "${EnvironmentName}:PrivateSubnetOne"
            - Fn::ImportValue: !Sub "${EnvironmentName}:PrivateSubnetTwo"
      TaskDefinition: !Ref IngressTaskDefinition
      LoadBalancers:
        - ContainerName: envoy
          ContainerPort: 9080
          TargetGroupArn: !Ref IngressTargetGroup

  PublicLoadBalancer:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties:
      Scheme: internet-facing
      Subnets:
        - Fn::ImportValue: !Sub "${EnvironmentName}:PublicSubnetOne"
        - Fn::ImportValue: !Sub "${EnvironmentName}:PublicSubnetTwo"
      Type: network

  IngressTargetGroup:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Properties:
      HealthCheckIntervalSeconds: 10
      HealthCheckPort: 9080
      HealthCheckProtocol: TCP
      HealthCheckTimeoutSeconds: 10
      HealthyThresholdCount: 2
      TargetType: ip
      Name: !Sub "${EnvironmentName}-ingress"
      Port: 80
      Protocol: TCP
      UnhealthyThresholdCount: 2
      TargetGroupAttributes:
        - Key: deregistration_delay.timeout_seconds
          Value: 5
      VpcId:
        Fn::ImportValue: !Sub "${EnvironmentName}:VpcId"

  PublicLoadBalancerListener:
    Type: AWS::ElasticLoadBalancingV2::Listener
    DependsOn:
      - PublicLoadBalancer
    Properties:
      DefaultActions:
        - TargetGroupArn: !Ref IngressTargetGroup
          Type: 'forward'
      LoadBalancerArn: !Ref PublicLoadBalancer
      Port: 80
      Protocol: TCP



# These are the values output by the CloudFormation template. Be careful
# about changing any of them, because of them are exported with specific
# names so that the other task related CF templates can use them.
Outputs:
  MeshName:
    Description: The name of the App MeshName
    Value: !GetAtt Mesh.MeshName
    Export:
      Name: !Sub ${EnvironmentName}:MeshName
  EnvoyImage:
    Value: !Ref EnvoyImage
    Export:
      Name: !Sub ${EnvironmentName}:EnvoyImage
  IngressEndpoint:
    Value: !GetAtt PublicLoadBalancer.DNSName
    Export:
      Name: !Sub ${EnvironmentName}:IngressEndpoint