ECS-INFRA.yml

AWSTemplateFormatVersion: '2010-09-09'
Description: AWS Fargate cluster that can span public and private subnets. Supports
             public facing load balancers, private internal load balancers, and
             both internal and external service discovery namespaces.
Parameters:
  EnvironmentName:
    Type: String
    Default: production
    Description: "A friendly environment name that will be used for namespacing all cluster resources. Example: staging, qa, or production"
Mappings:
  SubnetConfig:
    VPC:
      CIDR: '10.0.0.0/16'
    PublicOne:
      CIDR: '10.0.0.0/24'
    PublicTwo:
      CIDR: '10.0.1.0/24'
    PrivateOne:
      CIDR: '10.0.2.0/24'
    PrivateTwo:
      CIDR: '10.0.3.0/24'
Resources:
  # VPC in which containers will be networked.
  # It has two public subnets, and two private subnets.
  # We distribute the subnets across the first two available subnets
  # for the region, for high availability.
  VPC:
    Type: AWS::EC2::VPC
    Properties:
      EnableDnsSupport: true
      EnableDnsHostnames: true
      CidrBlock: !FindInMap ['SubnetConfig', 'VPC', 'CIDR']

  # Two public subnets, where containers can have public IP addresses
  PublicSubnetOne:
    Type: AWS::EC2::Subnet
    Properties:
      AvailabilityZone: !Select
        - 0
        - Fn::GetAZs: !Ref 'AWS::Region'
      VpcId: !Ref 'VPC'
      CidrBlock: !FindInMap ['SubnetConfig', 'PublicOne', 'CIDR']
      MapPublicIpOnLaunch: true
  PublicSubnetTwo:
    Type: AWS::EC2::Subnet
    Properties:
      AvailabilityZone: !Select
        - 1
        - Fn::GetAZs: !Ref 'AWS::Region'
      VpcId: !Ref 'VPC'
      CidrBlock: !FindInMap ['SubnetConfig', 'PublicTwo', 'CIDR']
      MapPublicIpOnLaunch: true

  # Two private subnets where containers will only have private
  # IP addresses, and will only be reachable by other members of the
  # VPC
  PrivateSubnetOne:
    Type: AWS::EC2::Subnet
    Properties:
      AvailabilityZone: !Select
        - 0
        - Fn::GetAZs: !Ref 'AWS::Region'
      VpcId: !Ref 'VPC'
      CidrBlock: !FindInMap ['SubnetConfig', 'PrivateOne', 'CIDR']
  PrivateSubnetTwo:
    Type: AWS::EC2::Subnet
    Properties:
      AvailabilityZone: !Select
        - 1
        - Fn::GetAZs: !Ref 'AWS::Region'
      VpcId: !Ref 'VPC'
      CidrBlock: !FindInMap ['SubnetConfig', 'PrivateTwo', 'CIDR']

  # Setup networking resources for the public subnets. Containers
  # in the public subnets have public IP addresses and the routing table
  # sends network traffic via the internet gateway.
  InternetGateway:
    Type: AWS::EC2::InternetGateway
  GatewayAttachement:
    Type: AWS::EC2::VPCGatewayAttachment
    Properties:
      VpcId: !Ref 'VPC'
      InternetGatewayId: !Ref 'InternetGateway'
  PublicRouteTable:
    Type: AWS::EC2::RouteTable
    Properties:
      VpcId: !Ref 'VPC'
  PublicRoute:
    Type: AWS::EC2::Route
    DependsOn: GatewayAttachement
    Properties:
      RouteTableId: !Ref 'PublicRouteTable'
      DestinationCidrBlock: '0.0.0.0/0'
      GatewayId: !Ref 'InternetGateway'
  PublicSubnetOneRouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PublicSubnetOne
      RouteTableId: !Ref PublicRouteTable
  PublicSubnetTwoRouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PublicSubnetTwo
      RouteTableId: !Ref PublicRouteTable

  # Setup networking resources for the private subnets. Containers
  # in these subnets have only private IP addresses, and must use a NAT
  # gateway to talk to the internet. We launch two NAT gateways, one for
  # each private subnet.
  NatGatewayOneAttachment:
    Type: AWS::EC2::EIP
    DependsOn: GatewayAttachement
    Properties:
        Domain: vpc
  NatGatewayTwoAttachment:
    Type: AWS::EC2::EIP
    DependsOn: GatewayAttachement
    Properties:
        Domain: vpc
  NatGatewayOne:
    Type: AWS::EC2::NatGateway
    Properties:
      AllocationId: !GetAtt NatGatewayOneAttachment.AllocationId
      SubnetId: !Ref PublicSubnetOne
  NatGatewayTwo:
    Type: AWS::EC2::NatGateway
    Properties:
      AllocationId: !GetAtt NatGatewayTwoAttachment.AllocationId
      SubnetId: !Ref PublicSubnetTwo
  PrivateRouteTableOne:
    Type: AWS::EC2::RouteTable
    Properties:
      VpcId: !Ref 'VPC'
  PrivateRouteOne:
    Type: AWS::EC2::Route
    Properties:
      RouteTableId: !Ref PrivateRouteTableOne
      DestinationCidrBlock: 0.0.0.0/0
      NatGatewayId: !Ref NatGatewayOne
  PrivateRouteTableOneAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      RouteTableId: !Ref PrivateRouteTableOne
      SubnetId: !Ref PrivateSubnetOne
  PrivateRouteTableTwo:
    Type: AWS::EC2::RouteTable
    Properties:
      VpcId: !Ref 'VPC'
  PrivateRouteTwo:
    Type: AWS::EC2::Route
    Properties:
      RouteTableId: !Ref PrivateRouteTableTwo
      DestinationCidrBlock: 0.0.0.0/0
      NatGatewayId: !Ref NatGatewayTwo
  PrivateRouteTableTwoAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      RouteTableId: !Ref PrivateRouteTableTwo
      SubnetId: !Ref PrivateSubnetTwo

  ####
  # ALB related resources
  ####
  PublicLoadBalancerSG:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Access to the public facing load balancer
      VpcId: !Ref 'VPC'
      SecurityGroupIngress:
          - 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:
        - !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
      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
  ####
  # ECS related resources
  ####
  ECSCluster:
    Type: AWS::ECS::Cluster
    Properties:
      ClusterName: 'blog'
  ContainerSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Access to the containers
      VpcId: !Ref 'VPC'
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 0
          ToPort: 65535
          SourceSecurityGroupId: !Ref 'PublicLoadBalancerSG'
  ContainerSecurityGroupDB:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Security group for DB to services
      VpcId: !Ref 'VPC'
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: '3306'
          ToPort: '3306'
          SourceSecurityGroupId: !Ref 'ContainerSecurityGroup'
  # A role used to allow AWS Autoscaling to inspect stats and adjust scaleable targets
  # on your AWS account
  AutoscalingRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Statement:
        - Effect: Allow
          Principal:
            Service: [application-autoscaling.amazonaws.com]
          Action: ['sts:AssumeRole']
      Path: /
      Policies:
      - PolicyName: service-autoscaling
        PolicyDocument:
          Statement:
          - Effect: Allow
            Action:
              - 'application-autoscaling:*'
              - 'cloudwatch:DescribeAlarms'
              - 'cloudwatch:PutMetricAlarm'
              - 'ecs:DescribeServices'
              - 'ecs:UpdateService'
            Resource: '*'

  # 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: '*'

  # This is a role which is used by the ECS tasks themselves.
  ECSTaskExecutionRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Statement:
        - Effect: Allow
          Principal:
            Service: [ecs-tasks.amazonaws.com]
          Action: ['sts:AssumeRole']
      Path: /
      Policies:
        - PolicyName: AmazonECSTaskExecutionRolePolicy
          PolicyDocument:
            Statement:
            - Effect: Allow
              Action:
                # Allow the ECS Tasks to download images from ECR
                - 'ecr:GetAuthorizationToken'
                - 'ecr:BatchCheckLayerAvailability'
                - 'ecr:GetDownloadUrlForLayer'
                - 'ecr:BatchGetImage'

                # Allow the ECS tasks to upload logs to CloudWatch
                - 'logs:CreateLogStream'
                - 'logs:PutLogEvents'
              Resource: '*'

# 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:
  ClusterName:
    Description: The name of the ECS cluster
    Value: !Ref 'ECSCluster'
    Export:
      Name: !Sub ${EnvironmentName}:ClusterName
  AutoscalingRole:
    Description: The ARN of the role used for autoscaling
    Value: !GetAtt 'AutoscalingRole.Arn'
    Export:
      Name: !Sub ${EnvironmentName}:AutoscalingRole
  ECSRole:
    Description: The ARN of the ECS role
    Value: !GetAtt 'ECSRole.Arn'
    Export:
      Name: !Sub ${EnvironmentName}:ECSRole
  ECSTaskExecutionRole:
    Description: The ARN of the ECS role
    Value: !GetAtt 'ECSTaskExecutionRole.Arn'
    Export:
      Name: !Sub ${EnvironmentName}:ECSTaskExecutionRole
  VpcId:
    Description: The ID of the VPC that this stack is deployed in
    Value: !Ref 'VPC'
    Export:
      Name: !Sub ${EnvironmentName}:VpcId
  PublicSubnetOne:
    Description: Public subnet one
    Value: !Ref 'PublicSubnetOne'
    Export:
      Name: !Sub ${EnvironmentName}:PublicSubnetOne
  PublicSubnetTwo:
    Description: Public subnet two
    Value: !Ref 'PublicSubnetTwo'
    Export:
      Name: !Sub ${EnvironmentName}:PublicSubnetTwo
  PrivateSubnetOne:
    Description: Private subnet one
    Value: !Ref 'PrivateSubnetOne'
    Export:
      Name: !Sub ${EnvironmentName}:PrivateSubnetOne
  PrivateSubnetTwo:
    Description: Private subnet two
    Value: !Ref 'PrivateSubnetTwo'
    Export:
      Name: !Sub ${EnvironmentName}:PrivateSubnetTwo
  ContainerSecurityGroup:
    Description: A security group used to allow Fargate containers to receive traffic
    Value: !Ref 'ContainerSecurityGroup'
    Export:
      Name: !Sub ${EnvironmentName}:ContainerSecurityGroup
  ContainerSecurityGroupDB:
    Description: A security group used to allow DB Fargate containers to receive traffic From Web
    Value: !Ref 'ContainerSecurityGroupDB'
    Export:
      Name: !Sub ${EnvironmentName}:ContainerSecurityGroupDB
  PublicLoadBalancerListener:
    Description: PublicLoadBalancerListener
    Value: !Ref 'PublicLoadBalancerListener'
    Export:
      Name: !Sub ${EnvironmentName}:PublicListener