Cloudwatch failedinvocation error no logs available

Question

I have set up a Cloudwatch rule event where an ECS task definition is started when a previous task definition is completed.

I can see the event triggers the task definition however it fails.

The only visibility of this failure is in the rule metrics, where I see the metric failedinnvocations.

Question, are there any logs to see why the trigger failed?

I can manually set up the rule via the management console and everything works fine.

The error occurs when I set up the rule via a cloudformation template.

I have compared the two rules and both are identical, except the role. However, both roles have the same permissions.

Solution 1

If the rule has been successfully triggered, but the invocation on the target failed, you should see a trace of the API call in the Event History inside the AWS CloudTrail looking at the errorCode and errorMessage properties:

{
   [..]
   "errorCode": "InvalidInputException",
   "errorMessage": "Artifacts type is required",
   [..]
}

Solution 2

This stumped us for ages, the main issue is the role problem Nathan B mentions but something else that tripped us up is that Scheduled Containers won't work in awsvpc mode (and by extension Fargate). Here's a sample CloudFormation template:

---
AWSTemplateFormatVersion: 2010-09-09
Description: Fee Recon infrastructure

Parameters:
  
  ClusterArn:
    Type: String
    Description: The Arn of the ECS Cluster to run the scheduled container on

  SecurityGroup:
    Type: String
    Description: The security group the task will use

  Subnet0:
    Type: String
    Description: A subnet that the task will run in

  Subnet1:
    Type: String
    Description: A subnet that the task will run in

Resources:

  TaskRole:
    Type: AWS::IAM::Role
    Properties:
      Path: /
      AssumeRolePolicyDocument:
        Statement:
          - Action:
              - sts:AssumeRole
            Effect: Allow
            Principal:
              Service:
                - ecs-tasks.amazonaws.com
        Version: 2012-10-17
      Policies:
       - PolicyName: TaskPolicy
         PolicyDocument:
           Version: 2012-10-17
           Statement:
             - Effect: Allow
               Action:
                 - 'ses:SendEmail'
                 - 'ses:SendRawEmail'
               Resource: '*'

  TaskDefinition:
    Type: AWS::ECS::TaskDefinition
    Properties:
      TaskRoleArn: !Ref TaskRole
      ContainerDefinitions:
        - Name: !Sub my-container
          Essential: true
          Image: !Sub <aws-account-no>.dkr.ecr.eu-west-1.amazonaws.com/mycontainer
          Memory: 2048
          Cpu: 1024

  CloudWatchEventECSRole:
   Type: AWS::IAM::Role
   Properties:
     AssumeRolePolicyDocument:
       Version: 2012-10-17
       Statement:
         - Effect: Allow
           Principal:
             Service:
               - events.amazonaws.com
           Action:
             - sts:AssumeRole
     Path: /
     Policies:
       - PolicyName: CloudwatchEventsInvokeECSRunTask
         PolicyDocument:
           Version: 2012-10-17
           Statement:
             - Effect: Allow
               Action: 'ecs:RunTask'
               Resource: !Ref TaskDefinition

  TaskSchedule:
    Type: AWS::Events::Rule
    Properties:
      Description: Runs every 10 minutes
      Name: ScheduledTask
      ScheduleExpression: cron(0/10 * * * ? *)
      State: ENABLED
      Targets:
        - Id: ScheduledEcsTask
          RoleArn: !GetAtt CloudWatchEventECSRole.Arn
          EcsParameters:
            TaskDefinitionArn: !Ref TaskDefinition
            TaskCount: 1
            NetworkConfiguration:
              AwsVpcConfiguration:
                SecurityGroups:
                  - !Ref SecurityGroup
                Subnets:
                  - !Ref PrivateSubnet0
                  - !Ref PrivateSubnet1
          Arn: !Ref ClusterArn

Note: I've added the ClusterArn as a parameter to the script as well as the security group and subnets you wish the task to run in.

There are two roles you need to care about, the first is the role (TaskRole) for the task itself: in this example the container just sends an email using SES so it has the necessary permissions. The second role (CloudWatchEventECSRole) is the one that makes it all work, note that in its Policies array the principle is events.amazonaws.com and the resource is the ECS task defined in the template.

Solution 3

CloudTrail logs helped. event Name is RunTask. The issue was: "errorCode": "InvalidParameterException", "errorMessage": "Override for container named rds-task is not a container in the TaskDefinition.",

The AWS documentation for debugging CloudWatch events is here:
https://docs.aws.amazon.com/AmazonCloudWatch/latest/events/CWE_Troubleshooting.html

I opened a PR to add documentation for debugging failed ECS Task Invocations from CloudWatch Events:
https://github.com/awsdocs/amazon-cloudwatch-events-user-guide/pull/12/files

Solution 4

This problem was due to not setting the principle services to include events.amazonaws.com. The task couldn't assume the role.

Shame aws doesn't have better logging for failedinvocations.

Solution 5

In case other people come here looking for the setup necessary to make this work for a task in Fargate. There is some extra configuration in addition to Stefano's answer. Running tasks in Fargate requires setting up an execution role, so you need to enable the CloudWatchEventECSRole to use it. Add this statement to that role:

{
    "Effect": "Allow",
    "Action": "iam:PassRole",
    "Resource": [
        "arn:aws:iam::<account>:role/<executionRole>"
    ]
}

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