Multiprocess supervisor support for 1 worker at startup

[jeffdarmawan]

Hi devs,

I've been developing a FastAPI product for a while now and noticed that Uvicorn's Multiprocess supervisor has the capability to add and remove workers during runtime by performing certain terminal commands (SIGTTIN/SIGTTOU). While I love this feature, I regret to know that it is only available if I start the Uvicorn app with a minimum 2 workers (I'm looking at https://github.com/encode/uvicorn/blob/master/uvicorn/main.py#L573-L575).

Will there be a possibility where I can run the app with 1 worker at startup but still benefit from the Multiprocess supervisor? Maybe by introducing an option to explicitly specify which supervisor the user wants to use.

I appreciate your time and consideration, have a great day!