---
AWSTemplateFormatVersion: '2010-09-09'
Description: Lambda function used by Handel for auto-scaling ECS clusters

Resources:
  EventsRule:
    Type: 'AWS::Events::Rule'
    Properties:
      Description: Fires Handel ECS auto-scaling lambda on a schedule
      ScheduleExpression: cron(0/1 * * * ? *)
      Name: HandelEcsAutoScalingLambda
      State: ENABLED
      Targets:
      - Id: 'HandelEcsAutoScalingLambda'
        Arn: !GetAtt Function.Arn
  Role:
    Type: AWS::IAM::Role
    Properties:
      RoleName: HandelEcsAutoScalingLambda
      Path: "/services/"
      AssumeRolePolicyDocument:
        Version: "2012-10-17"
        Statement:
          - Effect: "Allow"
            Principal:
              Service:
              - "lambda.amazonaws.com"
            Action:
            - "sts:AssumeRole"
      {{#if permissionsBoundary}}
      PermissionsBoundary: {{permissionsBoundary}}
      {{/if}}
  Policy:
    Type: AWS::IAM::Policy
    Properties:
      PolicyName: HandelEcsAutoScalingLambda
      Roles:
      - !Ref Role
      PolicyDocument:
        Version: "2012-10-17"
        Statement:
        - Effect: Allow
          Action:
          - 'logs:CreateLogGroup'
          - 'logs:CreateLogStream'
          - 'logs:PutLogEvents'
          Resource:
          - 'arn:aws:logs:*:*:*'
        - Effect: Allow
          Action:
          - 'ecs:ListClusters'
          - 'ecs:DescribeClusters'
          - 'ecs:ListContainerInstances'
          - 'ecs:DescribeContainerInstances'
          - 'ecs:DescribeTasks'
          - 'ecs:DescribeTaskDefinition'
          - 'ecs:ListTasks'
          Resource:
          - '*'
        - Effect: Allow
          Action:
          - 'cloudwatch:PutMetricData'
          Resource:
          - '*'
  Function:
    Type: AWS::Lambda::Function
    Properties:
      Code:
        S3Bucket: {{s3Bucket}}
        S3Key: {{s3Key}}
      Description: Lambda function used by Handel for auto-scaling ECS clusters
      FunctionName: HandelEcsAutoScalingLambda
      Handler: index.handler
      MemorySize: 128
      Role: !GetAtt Role.Arn
      Runtime: nodejs12.x
      Timeout: 300
  PermissionForEventsToInvokeLambda:
    Type: "AWS::Lambda::Permission"
    Properties: 
      FunctionName: !Ref Function
      Action: "lambda:InvokeFunction"
      Principal: "events.amazonaws.com"
      SourceArn: !GetAtt EventsRule.Arn