AWSTemplateFormatVersion: "2010-09-09"
Description: Create Spring Boot applications on ECS Fargate with Redis Caching.

Parameters:

  InfraStackName:
    Description: Name of the Infrastructure stack name that export required input parameters.
    Type: String
    Default: infra-stack

  ServiceName:
    Description: The name of the service.
    Type: String
    Default: java-spring-boot

  ContainerImageTag:
    Type: String
    Description: The tag name of the image to be deployed
    Default: 1.0

  ContainerPort:
    Description: Container port to be used
    Type: String
    Default: 8080

  DesiredCount:
    Description: The number of tasks to run in this cluster when first deployed
    Type: Number
    Default: 1

  MinContainers:
    Description: The minimum number of containers that we will scale down to
    Type: Number
    Default: 1

  MaxContainers:
    Description: The maximum number of containers that we will scale up to
    Type: Number
    Default: 10

  AutoScalingCpuTargetValue:
    Description: The average CPU utilisation before autoscaling will take effect
    Type: Number
    Default: 50

  TaskCpu:
    Description: The number of cpu units used by the task
    Type: Number
    Default: 512

  TaskMemory:
    Description: The amount (in MiB) of memory used by the task.
    Type: Number
    Default: 1024

Resources:
  TaskDefinition:
    Type: "AWS::ECS::TaskDefinition"
    Properties:
      ExecutionRoleArn: !GetAtt ExecutionRole.Arn
      TaskRoleArn: !GetAtt TaskRole.Arn
      ContainerDefinitions:
        - Image: !Join ['', [ Fn::ImportValue: !Sub "${InfraStackName}-RepositoryUri", !Sub ":${ContainerImageTag}"]]
          Name:  !Sub "${AWS::StackName}-${ServiceName}"
          LogConfiguration:
            LogDriver: awslogs
            Options:
              "awslogs-group" : !Ref TaskDefinitionLogGroup
              "awslogs-region" : !Ref AWS::Region
              "awslogs-stream-prefix" : !Sub "${AWS::StackName}-${ServiceName}"
          PortMappings:
            - ContainerPort: !Ref ContainerPort
          Environment:
            - Name: spring.profiles.active
              Value: cloud
            - Name: REDIS_ADDRESS
              Value:
                Fn::ImportValue:
                  !Sub "${InfraStackName}-RedisAddress"
      Cpu: !Ref TaskCpu
      Family: !Sub "${AWS::StackName}-${ServiceName}"
      Memory: !Ref TaskMemory
      NetworkMode: awsvpc
      RequiresCompatibilities:
        - FARGATE
  ExecutionRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: '2012-10-17'
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - ecs-tasks.amazonaws.com
            Action:
              - sts:AssumeRole
      Policies:
        - PolicyName: loggroup-policy
          PolicyDocument:
            Statement:
              - Effect: Allow
                Action:
                  - "ecr:GetAuthorizationToken"
                  - "ecr:BatchCheckLayerAvailability"
                  - "ecr:GetDownloadUrlForLayer"
                  - "ecr:BatchGetImage"
                  - "logs:CreateLogStream"
                  - "logs:PutLogEvents"
                Resource: "*"
        - PolicyName: ssm-policy
          PolicyDocument:
            Statement:
              - Effect: Allow
                Action:
                  - "ssm:GetParameters"
                  - "ssm:GetParametersByPath"
                  - "secretsmanager:GetSecretValue"
                  - "kms:Decrypt"
                Resource: "*"
  TaskRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: '2012-10-17'
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - ecs-tasks.amazonaws.com
            Action:
              - sts:AssumeRole
      Policies:
        - PolicyName: ssm-policy
          PolicyDocument:
            Statement:
              - Effect: Allow
                Action:
                  - "ssm:GetParameters"
                  - "ssm:GetParametersByPath"
                  - "secretsmanager:GetSecretValue"
                  - "kms:Decrypt"
                Resource: "*"
  TaskDefinitionLogGroup:
    Type: "AWS::Logs::LogGroup"
    Properties:
      LogGroupName: !Sub "${AWS::StackName}-${ServiceName}-logs"
      RetentionInDays: 7

  LoadBalancerRule:
    Type: AWS::ElasticLoadBalancingV2::ListenerRule
    Properties:
      ListenerArn:
        Fn::ImportValue:
          !Sub "${InfraStackName}-LoadBalancerListener"
      Priority: 1
      Conditions:
        - Field: path-pattern
          Values:
          - '*'
      Actions:
        - TargetGroupArn: !Ref TargetGroup
          Type: forward
  TargetGroup:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Properties:
      VpcId:
        Fn::ImportValue:
          !Sub "${InfraStackName}-VpcId"
      Port: !Ref ContainerPort
      Protocol: HTTP
      TargetType: ip
      Matcher:
        HttpCode: 200,301,302,304,404
      HealthCheckIntervalSeconds: 20
      HealthCheckPath: /
      HealthCheckProtocol: HTTP
      HealthCheckTimeoutSeconds: 15
      HealthyThresholdCount: 2


  Service:
    Type: AWS::ECS::Service
    Properties:
      ServiceName: !Sub "${AWS::StackName}-${ServiceName}-${ContainerPort}"
      Cluster:
        Fn::ImportValue:
          !Sub "${InfraStackName}-EcsClusterName"
      LaunchType: FARGATE
      PlatformVersion: 1.4.0
      DeploymentConfiguration:
        DeploymentCircuitBreaker:
          Enable: True
          Rollback: True
        MaximumPercent: 200
        MinimumHealthyPercent: 50
      DesiredCount: !Ref DesiredCount
      TaskDefinition: !Ref TaskDefinition
      NetworkConfiguration:
        AwsvpcConfiguration:
          AssignPublicIp: ENABLED
          SecurityGroups:
            - !Ref ServiceSG
          Subnets:
            - Fn::ImportValue:
                !Sub "${InfraStackName}-PublicSubnetAz1"
            - Fn::ImportValue:
                !Sub "${InfraStackName}-PublicSubnetAz2"
      LoadBalancers:
        - ContainerName: !Sub "${AWS::StackName}-${ServiceName}"
          ContainerPort: !Ref ContainerPort
          TargetGroupArn: !Ref TargetGroup
  ServiceSG:
    Type: AWS::EC2::SecurityGroup
    Properties:
      VpcId:
        Fn::ImportValue:
          !Sub "${InfraStackName}-VpcId"
      GroupDescription: SGP for Cluster
      SecurityGroupIngress:
        - SourceSecurityGroupId:
            Fn::ImportValue:
              !Sub "${InfraStackName}-LoadBalancerSecurityGroup"
          IpProtocol: tcp
          FromPort: !Ref ContainerPort
          ToPort: !Ref ContainerPort

  AutoScalingRole:
    Type: AWS::IAM::Role
    Properties:
      RoleName: !Join ['', [ !Sub "${AWS::StackName}-${ServiceName}", AutoScalingRole]]
      AssumeRolePolicyDocument:
        Statement:
          - Effect: Allow
            Principal:
              Service: application-autoscaling.amazonaws.com
            Action: 'sts:AssumeRole'
      Policies:
        - PolicyName: ecs-autoscaling
          PolicyDocument:
            Statement:
              - Effect: Allow
                Action:
                  - "ecs:DescribeServices"
                  - "ecs:UpdateService"
                Resource: "*"
              - Effect: Allow
                Action:
                  - "cloudwatch:DescribeAlarms"
                  - "cloudwatch:PutMetricAlarm"
                Resource: "*"

  AutoScalingTarget:
    Type: AWS::ApplicationAutoScaling::ScalableTarget
    Properties:
      MinCapacity: !Ref MinContainers
      MaxCapacity: !Ref MaxContainers
      ResourceId: 
        Fn::Join:
          - "/"
          - - "service"
            - Fn::ImportValue: 
                !Sub "${InfraStackName}-EcsClusterName"
            - !GetAtt Service.Name
      ScalableDimension: ecs:service:DesiredCount
      ServiceNamespace: ecs
      RoleARN: !GetAtt AutoScalingRole.Arn
      
  AutoScalingPolicy:
    Type: AWS::ApplicationAutoScaling::ScalingPolicy
    Properties:
      PolicyName: !Join ['', [!Sub "${AWS::StackName}-${ServiceName}", AutoScalingPolicy]]
      PolicyType: TargetTrackingScaling
      ScalingTargetId: !Ref AutoScalingTarget
      TargetTrackingScalingPolicyConfiguration:
        PredefinedMetricSpecification:
          PredefinedMetricType: ECSServiceAverageCPUUtilization
        ScaleInCooldown: 300
        ScaleOutCooldown: 300
        TargetValue: !Ref AutoScalingCpuTargetValue