AWSTemplateFormatVersion: 2010-09-09
Description: CloudFormation template for a full E2E ECS service with CI/CD on Fargate.
Parameters:
  VPC:
    Type: AWS::EC2::VPC::Id
    Default: vpc-6f596904
    Description: The id of the VPC
  SubnetA:
    Type: AWS::EC2::Subnet::Id
    Default: subnet-6e596905
    Description: The id of the first subnet
  SubnetB:
    Type: AWS::EC2::Subnet::Id
    Default: subnet-6d596906
    Description: The id of the second subnet

  DatabaseSecurityGroup:
    Type: String
    Description: Security group id to access the database

  Image:
    Type: String
    # Docker image for this service. It must have a latest tag
    # Example 260851616142.dkr.ecr.eu-west-1.amazonaws.com/nginx
  EnvironmentName:
    Type: String
    Description: Name of env such as staging or production

  BernardSQSPolicy:
    Type: String

  # CPU
  # 256 (.25 vCPU) - Available memory values: 0.5GB, 1GB, 2GB
  # 512 (.5 vCPU) - Available memory values: 1GB, 2GB, 3GB, 4GB
  # 1024 (1 vCPU) - Available memory values: 2GB, 3GB, 4GB, 5GB, 6GB, 7GB, 8GB
  # 2048 (2 vCPU) - Available memory values: Between 4GB and 16GB in 1GB increments
  # 4096 (4 vCPU) - Available memory values: Between 8GB and 30GB in 1GB increments
  CpuSize:
    Type: Number

  # Memory
  # 0.5GB, 1GB, 2GB - Available cpu values: 256 (.25 vCPU)
  # 1GB, 2GB, 3GB, 4GB - Available cpu values: 512 (.5 vCPU)
  # 2GB, 3GB, 4GB, 5GB, 6GB, 7GB, 8GB - Available cpu values: 1024 (1 vCPU)
  # Between 4GB and 16GB in 1GB increments - Available cpu values: 2048 (2 vCPU)
  # Between 8GB and 30GB in 1GB increments - Available cpu values: 4096 (4 vCPU)
  MemorySize:
    Type: String

  ContainerPort:
    Type: Number
    Default: 80
  LoadBalancerPort:
    Type: Number
    Default: 443
  HealthCheckPath:
    Type: String
    Default: /

  Certificate:
    Type: String
    # Update with the certificate ARN from Certificate Manager, which must exist in the same region.
  HostedZoneName:
    Type: String
    Default: photowall.com
  Subdomain:
    Type: String

    # for autoscaling
  MinContainers:
    Type: Number
    Default: 1
  # for autoscaling
  MaxContainers:
    Type: Number
    Default: 4
  # target CPU utilization (%)
  AutoScalingTargetValue:
    Type: Number
    Default: 50

  # Github info for code pipeline
  GitHubRepo:
    Type: String
  GitHubBranch:
    Type: String
  GitHubToken:
    Type: String
    NoEcho: true
  GitHubUser:
    Type: String

Resources:
  Cluster:
    Type: AWS::ECS::Cluster
    Properties:
      ClusterName: !Join ['', [!Ref 'AWS::StackName', Cluster]]

  TaskDefinition:
    Type: AWS::ECS::TaskDefinition
    # Makes sure the log group is created before it is used.
    DependsOn: LogGroup
    Properties:
      # Name of the task definition. Subsequent versions of the task definition are grouped together under this name.
      Family: !Join ['', [!Ref 'AWS::StackName', TaskDefinition]]
      # awsvpc is required for Fargate
      NetworkMode: awsvpc
      RequiresCompatibilities:
        - FARGATE
      Cpu: !Ref CpuSize
      Memory: !Ref MemorySize
      # A role needed by ECS.
      # "The ARN of the task execution role that containers in this task can assume. All containers in this task are granted the permissions that are specified in this role."
      # "There is an optional task execution IAM role that you can specify with Fargate to allow your Fargate tasks to make API calls to Amazon ECR."
      ExecutionRoleArn: !Ref ExecutionRole
      # "The Amazon Resource Name (ARN) of an AWS Identity and Access Management (IAM) role that grants containers in the task permission to call AWS APIs on your behalf."
      TaskRoleArn: !Ref TaskRole
      ContainerDefinitions:
        - Name: !Ref AWS::StackName
          Image: !Sub ${AWS::AccountId}.dkr.ecr.${AWS::Region}.amazonaws.com/${AWS::StackName}:latest
          Environment:
            - Name: DEBUG
              Value: True
          PortMappings:
            - ContainerPort: !Ref ContainerPort
          # Define which parameters should be fetched
          Secrets:
            - { Name: "SQLALCHEMY_DATABASE_URI", ValueFrom: !Sub "arn:aws:ssm:${AWS::Region}:${AWS::AccountId}:parameter/${EnvironmentName}/SQLALCHEMY_DATABASE_URI" }
            - { Name: "API_KEYS", ValueFrom: !Sub "arn:aws:ssm:${AWS::Region}:${AWS::AccountId}:parameter/${EnvironmentName}/API2_API_KEYS" }
            - { Name: "BERNARD_QUEUE_URL", ValueFrom: !Sub "arn:aws:ssm:${AWS::Region}:${AWS::AccountId}:parameter/${EnvironmentName}/BERNARD_QUEUE_URL" }
          # Send logs to CloudWatch Logs
          LogConfiguration:
            LogDriver: awslogs
            Options:
              awslogs-region: !Ref AWS::Region
              awslogs-group: !Ref LogGroup
              awslogs-stream-prefix: ecs

  # A role needed by ECS
  ExecutionRole:
    Type: AWS::IAM::Role
    Properties:
      RoleName: !Join ['', [!Ref 'AWS::StackName', ExecutionRole]]
      AssumeRolePolicyDocument:
        Statement:
          - Effect: Allow
            Principal:
              Service: ecs-tasks.amazonaws.com
            Action: 'sts:AssumeRole'
      ManagedPolicyArns:
        - 'arn:aws:iam::aws:policy/service-role/AmazonECSTaskExecutionRolePolicy'
        - arn:aws:iam::aws:policy/AmazonSSMReadOnlyAccess
  # A role for the containers
  TaskRole:
    Type: AWS::IAM::Role
    Properties:
      RoleName: !Join ['', [!Ref 'AWS::StackName', TaskRole]]
      AssumeRolePolicyDocument:
        Statement:
          - Effect: Allow
            Principal:
              Service: ecs-tasks.amazonaws.com
            Action: 'sts:AssumeRole'
      ManagedPolicyArns:
        - !Ref BernardSQSPolicy


  # A role needed for auto scaling
  AutoScalingRole:
    Type: AWS::IAM::Role
    Properties:
      RoleName: !Join ['', [!Ref 'AWS::StackName', AutoScalingRole]]
      AssumeRolePolicyDocument:
        Statement:
          - Effect: Allow
            Principal:
              Service: ecs-tasks.amazonaws.com
            Action: 'sts:AssumeRole'
      ManagedPolicyArns:
        - 'arn:aws:iam::aws:policy/service-role/AmazonEC2ContainerServiceAutoscaleRole'

  ContainerSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: !Join ['', [!Ref 'AWS::StackName', ContainerSecurityGroup]]
      VpcId: !Ref VPC
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: !Ref ContainerPort
          ToPort: !Ref ContainerPort
          SourceSecurityGroupId: !Ref LoadBalancerSecurityGroup

  LoadBalancerSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: !Join ['', [!Ref 'AWS::StackName', LoadBalancerSecurityGroup]]
      VpcId: !Ref VPC
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: !Ref LoadBalancerPort
          ToPort: !Ref LoadBalancerPort
          CidrIp: 0.0.0.0/0

  Service:
    Type: AWS::ECS::Service
    # This dependency is needed so that the load balancer is setup correctly in time
    DependsOn:
      - ListenerHTTPS
    Properties:
      ServiceName: !Ref AWS::StackName
      Cluster: !Ref Cluster
      TaskDefinition: !Ref TaskDefinition
      DeploymentConfiguration:
        MinimumHealthyPercent: 100
        MaximumPercent: 200
      DesiredCount: 1
      # This may need to be adjusted if the container takes a while to start up
      HealthCheckGracePeriodSeconds: 30
      LaunchType: FARGATE
      NetworkConfiguration:
        AwsvpcConfiguration:
          # change to DISABLED if you're using private subnets that have access to a NAT gateway
          AssignPublicIp: ENABLED
          Subnets:
            - !Ref SubnetA
            - !Ref SubnetB
          SecurityGroups:
            - !Ref ContainerSecurityGroup
            - !Ref DatabaseSecurityGroup
      LoadBalancers:
        - ContainerName: !Ref AWS::StackName
          ContainerPort: !Ref ContainerPort
          TargetGroupArn: !Ref TargetGroup

  TargetGroup:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Properties:
      HealthCheckIntervalSeconds: 10
      # will look for a 200 status code by default unless specified otherwise
      HealthCheckPath: !Ref HealthCheckPath
      HealthCheckTimeoutSeconds: 5
      UnhealthyThresholdCount: 2
      HealthyThresholdCount: 2
      Name: !Join ['', [!Ref 'AWS::StackName', TargetGroup]]
      Port: !Ref ContainerPort
      Protocol: HTTP
      TargetGroupAttributes:
        - Key: deregistration_delay.timeout_seconds
          Value: 60 # default is 300
      TargetType: ip
      VpcId: !Ref VPC

  ListenerHTTPS:
    Type: AWS::ElasticLoadBalancingV2::Listener
    Properties:
      DefaultActions:
        - TargetGroupArn: !Ref TargetGroup
          Type: forward
      LoadBalancerArn: !Ref LoadBalancer
      Port: !Ref LoadBalancerPort
      Protocol: HTTPS
      Certificates:
        - CertificateArn: !Ref Certificate

  LoadBalancer:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties:
      LoadBalancerAttributes:
        # this is the default, but is specified here in case it needs to be changed
        - Key: idle_timeout.timeout_seconds
          Value: 60
      Name: !Join ['', [!Ref 'AWS::StackName', LoadBalancer]]
      # "internal" is also an option
      Scheme: internet-facing
      SecurityGroups:
        - !Ref LoadBalancerSecurityGroup
      Subnets:
        - !Ref SubnetA
        - !Ref SubnetB

  DNSRecord:
    Type: AWS::Route53::RecordSet
    Properties:
      HostedZoneName: !Join ['', [!Ref HostedZoneName, .]]
      Name: !Join ['', [!Ref Subdomain, ., !Ref HostedZoneName, .]]
      Type: A
      AliasTarget:
        DNSName: !GetAtt LoadBalancer.DNSName
        HostedZoneId: !GetAtt LoadBalancer.CanonicalHostedZoneID

  LogGroup:
    Type: AWS::Logs::LogGroup
    Properties:
      LogGroupName: !Join ['', [/ecs/, !Ref 'AWS::StackName', TaskDefinition]]

  AutoScalingTarget:
    Type: AWS::ApplicationAutoScaling::ScalableTarget
    Properties:
      MinCapacity: !Ref MinContainers
      MaxCapacity: !Ref MaxContainers
      ResourceId: !Join ['/', [service, !Ref Cluster, !GetAtt Service.Name]]
      ScalableDimension: ecs:service:DesiredCount
      ServiceNamespace: ecs
      # "The Amazon Resource Name (ARN) of an AWS Identity and Access Management (IAM) role that allows Application Auto Scaling to modify your scalable target."
      RoleARN: !GetAtt AutoScalingRole.Arn
  AutoScalingPolicy:
    Type: AWS::ApplicationAutoScaling::ScalingPolicy
    Properties:
      PolicyName: !Join ['', [!Ref 'AWS::StackName', AutoScalingPolicy]]
      PolicyType: TargetTrackingScaling
      ScalingTargetId: !Ref AutoScalingTarget
      TargetTrackingScalingPolicyConfiguration:
        PredefinedMetricSpecification:
          PredefinedMetricType: ECSServiceAverageCPUUtilization
        ScaleInCooldown: 10
        ScaleOutCooldown: 10
        # Keep things at or lower than 50% CPU utilization, for example
        TargetValue: !Ref AutoScalingTargetValue

  ## Deployment pipeline below
  CodeBuildServiceRole:
    Type: AWS::IAM::Role
    Properties:
      Path: /
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Principal:
              Service: codebuild.amazonaws.com
            Action: sts:AssumeRole
      Policies:
        - PolicyName: root
          PolicyDocument:
            Version: 2012-10-17
            Statement:
              - Resource: "*"
                Effect: Allow
                Action:
                  - logs:CreateLogGroup
                  - logs:CreateLogStream
                  - logs:PutLogEvents
                  - ecr:GetAuthorizationToken
              - Resource: !Sub arn:aws:s3:::${ArtifactBucket}/*
                Effect: Allow
                Action:
                  - s3:GetObject
                  - s3:PutObject
                  - s3:GetObjectVersion
              - Resource: !Sub arn:aws:ecr:${AWS::Region}:${AWS::AccountId}:repository/${AWS::StackName}
                Effect: Allow
                Action:
                  - ecr:GetDownloadUrlForLayer
                  - ecr:BatchGetImage
                  - ecr:BatchCheckLayerAvailability
                  - ecr:PutImage
                  - ecr:InitiateLayerUpload
                  - ecr:UploadLayerPart
                  - ecr:CompleteLayerUpload

  CodePipelineServiceRole:
    Type: AWS::IAM::Role
    Properties:
      Path: /
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Principal:
              Service: codepipeline.amazonaws.com
            Action: sts:AssumeRole
      Policies:
        - PolicyName: root
          PolicyDocument:
            Version: 2012-10-17
            Statement:
              - Resource:
                  - !Sub arn:aws:s3:::${ArtifactBucket}/*
                Effect: Allow
                Action:
                  - s3:PutObject
                  - s3:GetObject
                  - s3:GetObjectVersion
                  - s3:GetBucketVersioning
              - Resource: "*"
                Effect: Allow
                Action:
                  - ecs:List*
                  - ecs:Describe*
                  - ecs:RegisterTaskDefinition
                  - ecs:UpdateService
                  - codebuild:StartBuild
                  - codebuild:BatchGetBuilds
                  - iam:PassRole

  ArtifactBucket:
    Type: AWS::S3::Bucket
    DeletionPolicy: Retain

  CodeBuildProject:
    Type: AWS::CodeBuild::Project
    Properties:
      Artifacts:
        Type: CODEPIPELINE
      Source:
        Type: CODEPIPELINE
        BuildSpec: |
          version: 0.2
          phases:
            pre_build:
              commands:
                - $(aws ecr get-login --no-include-email)
                - TAG="$(echo $CODEBUILD_RESOLVED_SOURCE_VERSION | head -c 8)"
                - IMAGE_URI="${REPOSITORY_URI}:${TAG}"
                - IMAGE_LATEST_URI="${REPOSITORY_URI}:latest"
            build:
              commands:
                - docker build --tag "$IMAGE_URI" .
                - docker tag "$IMAGE_URI" "$IMAGE_LATEST_URI"
            post_build:
              commands:
                - docker push "$IMAGE_URI"
                - docker push "$IMAGE_LATEST_URI"
                - printf '[{"name":"%s","imageUri":"%s"}]' "$IMAGE_NAME" "$IMAGE_LATEST_URI" > images.json
          artifacts:
            files: images.json
      Environment:
        ComputeType: BUILD_GENERAL1_SMALL
        Image: aws/codebuild/docker:17.09.0
        Type: LINUX_CONTAINER
        EnvironmentVariables:
          - Name: AWS_DEFAULT_REGION
            Value: !Ref AWS::Region
          - Name: REPOSITORY_URI
            Value: !Ref Image
          - Name: IMAGE_NAME
            Value: !Ref AWS::StackName
      Name: !Ref AWS::StackName
      ServiceRole: !Ref CodeBuildServiceRole

  Pipeline:
    Type: AWS::CodePipeline::Pipeline
    Properties:
      RoleArn: !GetAtt CodePipelineServiceRole.Arn
      Name: !Join ['', [!Ref 'AWS::StackName', Pipeline]]
      ArtifactStore:
        Type: S3
        Location: !Ref ArtifactBucket
      Stages:
        - Name: Source
          Actions:
            - Name: App
              ActionTypeId:
                Category: Source
                Owner: ThirdParty
                Version: 1
                Provider: GitHub
              Configuration:
                Owner: !Ref GitHubUser
                Repo: !Ref GitHubRepo
                Branch: !Ref GitHubBranch
                OAuthToken: !Ref GitHubToken
              OutputArtifacts:
                - Name: App
              RunOrder: 1
        - Name: Build
          Actions:
            - Name: Build
              ActionTypeId:
                Category: Build
                Owner: AWS
                Version: 1
                Provider: CodeBuild
              Configuration:
                ProjectName: !Ref CodeBuildProject
              InputArtifacts:
                - Name: App
              OutputArtifacts:
                - Name: BuildOutput
              RunOrder: 1
        - Name: Deploy
          Actions:
            - Name: Deploy
              ActionTypeId:
                Category: Deploy
                Owner: AWS
                Version: 1
                Provider: ECS
              Configuration:
                ClusterName: !Ref Cluster
                ServiceName: !Ref Service
                FileName: images.json
              InputArtifacts:
                - Name: BuildOutput
              RunOrder: 1

# What outputs to expose
Outputs:
  Endpoint:
    Description: Endpoint
    Value: !Join ['', ['https://', !Ref DNSRecord]]
  Service:
    Value: Service
  PipelineUrl:
    Value: !Sub https://console.aws.amazon.com/codepipeline/home?region=${AWS::Region}#/view/${Pipeline}
  ContainerSecurityGroup:
    Value: !Ref ContainerSecurityGroup
  TaskDefinition:
    Value: !Ref TaskDefinition