Hey there! I noticed an extensive conversation around using the

ECSRun

run configuration, with

ECSAgent

and

Docker

storage. I am running into a similar issue - not entirely sure if there is a workaround currently, but here is the error I cannot get past:

[2021-03-31 15:09:51,907] ERROR - agent | Error while deploying flow: InvalidParameterException('An error occurred (InvalidParameterException) when calling the RunTask operation: Task definition does not support launch_type FARGATE.')

My setup:

# flow.py

import prefect
from prefect import Flow, task

@task
def say_hello():
    logger = prefect.context.get("logger")
    <http://logger.info|logger.info>("Got here!!!!")

with Flow("Test") as flow:
    say_hello()

--

# deploy.py

flow.run_configs = ECSRun(
    run_task_kwargs={'cluster': 'my-cluster'},
    execution_role_arn='arn:aws:iam::{ACCOUNT_NUMBER}:role/my-ecs-task-role',
    labels=['ecs']
)

flow.storage = Docker(
    env_vars=config.ENVIRONMENT_VARIABLES,
    extra_dockerfile_commands=[
        f"RUN pip install -e /service",
    ],
    files={f"{os.path.join(os.path.expanduser('~'), 'project')}": "/service"},
    image_name=config.DOCKER_IMAGE_NAME,
    image_tag=config.DOCKER_IMAGE_TAG,
    registry_url=config.DOCKER_REGISTRY_URL,
)

Here is how I am running the agent:

prefect agent ecs start --token {PREFECT_RUNNER_TOKEN} --cluster my-cluster --label ecs --launch-type FARGATE

My issue is, I have no idea if I am doing something wrong on the AWS side of things or not; I am trying to wrap my head around the root cause. I’m also noticing there are

task_definitions

and

task_role_arn

parameters and I’m unsure if I am expected to use them or not, where to set those up. Any insight would be extremely appreciated!

This is a known bug that shows up in some configurations. I recently got a reproducible example last night, currently debugging now.

Totally understood!

I'm not sure yet. Prefect 0.14.12 made some changes to the ECS agent, but none that I'd expect to cause this issue. If you want to try 0.14.11 and see if that works for you, that'd be helpful for debugging.

I just realized I’m actually running against 0.14.6

Should be fixed by https://github.com/PrefectHQ/prefect/pull/4325

Running against your branch, I’m hitting

botocore.errorfactory.ClientException: An error occurred (ClientException) when calling the RegisterTaskDefinition operation: Fargate requires task definition to have execution role ARN to support ECR images.

but I think thats on my end… testing some things currently.

That's saying you need to configure an execution role for your flow (or on the agent). This can be done by passing

execution_role_arn

to

ECSRun

or using the

--execution-role-arn

flag on the agent.