I notice that ECS functionality is actually part of the

prefect-aws

collection, not core Prefect. This error occurs when you're trying to run a flow using AWS ECS infrastructure, but haven't properly specified the task definition. To resolve this error, you need to ensure that: 1. You have installed the

prefect-aws

collection:

bash
pip install prefect-aws

2. When configuring your ECS work pool, you need to provide either: - A task definition ARN directly in your flow run configuration, or - A task definition in your work pool configuration The most common solution is to specify the task definition in your work pool configuration. Here's how to do it: 1. First, ensure you have a task definition created in AWS ECS 2. Then, when creating your ECS work pool, you can specify the task definition either: Using the UI: - Navigate to Work Pools in the Prefect UI - Create a new work pool with type "AWS ECS" - In the configuration, provide your task definition ARN in the appropriate field Or using the CLI:

bash
   prefect work-pool create my-ecs-pool --type ecs

Then update the work pool configuration with your task definition ARN. If you're still experiencing this error, could you please share: 1. How you're creating your work pool 2. The method you're using to deploy your flow 3. Whether you're trying to specify the task definition in the work pool configuration or at runtime This would help me provide more specific guidance for your use case. Also, make sure you're using the latest version of

prefect-aws

as there have been improvements to ECS configuration handling in recent versions.

@Marvin how can i edit the work pool definition in the ui to include the task definition arn? give me an example

Here's how to edit your ECS work pool to include the task definition ARN: 1. Go to the Prefect UI 2. Navigate to "Work Pools" in the left sidebar 3. Click on your existing ECS work pool 4. Click the "Edit" button 5. Look for the "Base Job Template" section 6. You'll need to modify the JSON configuration. Here's an example:

json
{
    "task_definition_arn": "arn:aws:ecs:us-east-1:123456789012:task-definition/your-task-definition:1",
    "cluster": "your-cluster-name",
    "vpc_id": "vpc-xxxxx",
    "task_role_arn": "arn:aws:iam::123456789012:role/your-task-role",
    "execution_role_arn": "arn:aws:iam::123456789012:role/your-execution-role",
    "subnet_ids": ["subnet-xxxxx", "subnet-yyyyy"],
    "security_group_ids": ["sg-xxxxx"],
    "region_name": "us-east-1"
}

The critical field here is

task_definition_arn

. This should follow the format:

arn:aws:ecs:[region]:[account-id]:task-definition/[task-definition-name]:[revision-number]

For example:

json
{
    "task_definition_arn": "arn:aws:ecs:us-east-1:123456789012:task-definition/prefect-task:1"
}

You can find your task definition ARN in several ways: 1. In the AWS Console: - Go to ECS > Task Definitions - Select your task definition - Copy the ARN from the details page 2. Using AWS CLI:

bash
aws ecs list-task-definitions

Remember that: - The task definition must exist in AWS ECS before you reference it - The revision number at the end (

:1

in the example) is important - make sure you're using the correct version - The task definition should have the necessary configuration to run your Prefect flow (appropriate container image, memory, CPU settings, etc.) After saving these changes, any new flow runs using this work pool will use the specified task definition. If you're still getting the error after making these changes, make sure to: 1. Check that the ARN is correctly formatted 2. Verify that your AWS credentials have permission to access this task definition 3. Ensure the task definition exists in the specified AWS region Would you like me to explain any part of this in more detail?

Here's the correct structure for the base job template in your ECS work pool:

json
{
    "job_configuration": {
        "task_definition_arn": "arn:aws:ecs:us-east-1:123456789012:task-definition/your-task-definition:1",
        "cluster": "your-cluster-name",
        "vpc_id": "vpc-xxxxx",
        "execution_role_arn": "arn:aws:iam::123456789012:role/your-execution-role",
        "subnet_ids": ["subnet-xxxxx", "subnet-yyyyy"],
        "security_group_ids": ["sg-xxxxx"]
    },
    "variables": {
        "region_name": "us-east-1"
    }
}

The key differences are: 1.

task_definition_arn

goes inside the

job_configuration

object 2. Region typically goes in the

variables

section 3. All ECS-specific configuration should be nested under

job_configuration

If you're still getting the error after making this change, could you: 1. Double-check that the task definition ARN is valid and accessible 2. Try running

aws ecs describe-task-definition --task-definition your-task-definition:1

in your terminal to verify the task definition exists 3. Confirm that the AWS credentials you're using have the necessary permissions Would you like me to help troubleshoot further if this structure doesn't resolve the error?