AWSTemplateFormatVersion: '2010-09-09'
Description: This template deploys an Amazon EventBridge rule that captures
             Elastic Container Service task history for persistence in Amazon CloudWatch.

Parameters:
  ServiceName:
    Type: string
    Description: The name of the ECS service that you would like to capture events from
  ServiceArn:
    Type: string
    Description: The full ARN of the service that you would like to capture events from

Resources:

  # A CloudWatch log group for persisting the Amazon ECS events
  ServiceEventLog:
    Type: AWS::Logs::LogGroup
    Properties:
      LogGroupName: !Sub /benchmark/${ServiceName}-events

  # Create the EventBridge rule that captures deployment events into the CloudWatch log group
  CaptureServiceDeploymentEvents:
    Type: AWS::Events::Rule
    Properties:
      Description: !Sub 'Capture service deployment events from the ECS service ${ServiceName}'
      # Which events to capture
      EventPattern:
        source:
          - aws.ecs
        detail-type:
          - "ECS Deployment State Change"
          - "ECS Service Action"
        resources:
          - !Ref ServiceArn
      # Where to send the events
      Targets:
        - Arn: !Sub arn:aws:logs:${AWS::Region}:${AWS::AccountId}:log-group:${ServiceEventLog}
          Id: 'CloudWatchLogGroup'

  # Create a log group resource policy that allows EventBridge to put logs into
  # the log group
  LogGroupForEventsPolicy:
    Type: AWS::Logs::ResourcePolicy
    Properties:
      PolicyName: EventBridgeToCWLogsPolicy
      PolicyDocument: !Sub
      - >
        {
          "Version": "2012-10-17",
          "Statement": [
            {
              "Sid": "EventBridgetoCWLogsPolicy",
              "Effect": "Allow",
              "Principal": {
                "Service": [
                  "delivery.logs.amazonaws.com",
                  "events.amazonaws.com"
                ]
              },
              "Action": [
                "logs:CreateLogStream",
                "logs:PutLogEvents"
              ],
              "Resource": [
                "${LogArn}"
              ]
            }
          ]
        }
      - { LogArn: !GetAtt ServiceEventLog.Arn, RuleArn: !GetAtt CaptureServiceDeploymentEvents.Arn}