How to pass worker options/parameters in gunicorn

Question

I am running an app which needed uvicorn's asycio loop, by default it uses auto and some time it randomly assign it to uvloop whihc breaks the behavior. So I use the following command

uvicorn myapp.server.api:app --loop asyncio --port 7474

This forces uvicorn to use asyncio loop. This works as expected.

Now I am trying to move this changes to gunicorn and uvicorn as worker, but I am couldn't find a way to pass this loop to uvicorn.

gunicorn myapp.server.api:app  -k uvicorn.workers.UvicornWorker --bind 0.0.0.0:7474

But this end up using default value i.e. auto and end up selecting loop type as uvloop. How can I force it to use asyncio worker. Help is appreciated.

Answer 1

The problem is gunicorn does not support passing options directly to uvicorn workers.

So, basically, you can create a custom UvicornWorker class where you override the default loop policy.

Here's an example:

# myapp/server/custom_worker.py

from uvicorn.workers import UvicornWorker

class CustomUvicornWorker(UvicornWorker):
    CONFIG_KWARGS = {"loop": "asyncio"}

Then:

gunicorn myapp.server.api:app -k myapp.server.custom_worker.CustomUvicornWorker --bind 0.0.0.0:7474