Prefect Worker Fails to Log Connection Errors to Server

[archi-max]

Bug summary

Description
When deploying a Prefect worker via Helm with a misconfigured serverApiConfig.apiUrl, the worker fails to establish a connection but only logs debug-level messages about the connection attempt without surfacing an explicit error. This occurs despite debug: true in the worker configuration.

01:53:36.933 | DEBUG | prefect.profiles - Using profile 'ephemeral'
01:53:38.718 | DEBUG | prefect.client - Connecting to API at http://prefect-server.prefect.svc.cluster.local/api/

Expected Behavior
The worker should log a clear error (e.g., ConnectionError, Timeout, or InvalidURL) when unable to reach the Prefect server, including retry attempts if applicable.

Version info

Version:             3.2.2
API version:         0.8.4
Python version:      3.11.11
Git commit:          d982c69a
Built:               Thu, Feb 13, 2025 10:53 AM
OS/Arch:             linux/x86_64
Profile:             ephemeral
Server type:         server
Pydantic version:    2.10.6
Integrations:
  prefect-redis:     0.2.2
  prefect-kubernetes: 0.5.3

Additional context

I am using the default prefect server service from the helm charts.

[desertaxle]

Thanks for the issue @archi-max! We log to stderr for connection errors and they look like this:

Traceback (most recent call last):
  File "/usr/local/lib/python3.12/site-packages/httpx/_transports/default.py", line 101, in map_httpcore_exceptions
    yield
  File "/usr/local/lib/python3.12/site-packages/httpx/_transports/default.py", line 394, in handle_async_request
    resp = await self._pool.handle_async_request(req)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/httpcore/_async/connection_pool.py", line 256, in handle_async_request
    raise exc from None
  File "/usr/local/lib/python3.12/site-packages/httpcore/_async/connection_pool.py", line 236, in handle_async_request
    response = await connection.handle_async_request(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/httpcore/_async/connection.py", line 101, in handle_async_request
    raise exc
  File "/usr/local/lib/python3.12/site-packages/httpcore/_async/connection.py", line 78, in handle_async_request
    stream = await self._connect(request)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/httpcore/_async/connection.py", line 124, in _connect
    stream = await self._network_backend.connect_tcp(**kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/httpcore/_backends/auto.py", line 31, in connect_tcp
    return await self._backend.connect_tcp(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/httpcore/_backends/anyio.py", line 113, in connect_tcp
    with map_exceptions(exc_map):
         ^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/contextlib.py", line 158, in __exit__
    self.gen.throw(value)
  File "/usr/local/lib/python3.12/site-packages/httpcore/_exceptions.py", line 14, in map_exceptions
    raise to_exc(exc) from exc
httpcore.ConnectError: [Errno -2] Name or service not known

I can see output like that when deploying a worker using the Helm chart with a bad API URL, so I'm unsure why you aren't seeing this in your setup. Do you have any custom handling for stderr?