Trouble Deploying Wave apps with Uvicorn

[tolmanam]

I don't understand the interactions between the waved server and the wave apps. I'd like to be able to spin up the waved server and then run my applications with uvicorn as described in the Deploying Wave apps docs but the two commands provided do not actually seem to be equivalent.

(venv) $ wave run --no-reload --no-autostart foo

(venv) $ uvicorn foo:main

Both seem to spin up the application API, but when I start the app with the wave command it also connects up to the running waved service and registers the route. The uvicorn command does not.

Am I missing a step?

Thanks.

versions:

• waved - 0.24.2 20221209122225
• h2o-wave - 0.24.2
• uvicorn - 0.20.0

[mturoci]

I will have a proper answer for you on Monday, but if you would like to investigate on your own, you can check

wave/py/h2o_wave/cli.py

Line 77 in 94cb690

def run(app: str, no_reload: bool, no_autostart: bool):

to get an idea of what wave run is actually doing.

I would also check if your config env variables are set correctly, e.g. H2O_WAVE_ADDRESS (address of the your wave server).

Please paste any outputs/errors you get along the way - will speed up my investigation.

I agree the deployment docs need some love though. I plan to write detailed instructions for deployments on AWS EC2, Render etc. but didnt have time so far.

[mturoci]

Seems to work fine for me.

@tolmanam Could you please paste screenshots of how you run both waved and uvicorn + the outputs you get? Do you set any wave env variables?

[tolmanam]

Ah! I was spoiled by how easy it was to just run 'wave' and didn't realize that I needed to provide the
H2O_WAVE_APP_ADDRESS environment variable.

The following command seems to "work".

> H2O_WAVE_APP_ADDRESS="http://127.0.0.1:8000" uvicorn counter:main

Would you consider that a reasonable way to set that variable? I'm happy to submit a merge request to update that documentation.

[mturoci]

Would you consider that a reasonable way to set that variable?

Yes, this looks good.

I needed to provide the H2O_WAVE_APP_ADDRESS environment variable

Ah, I see. uvicorn app:main works as long as default ports are used (http://localhost:10101 for wave server and http://localhost:8000 for wave app). If any of those is changed, it crashes. Would be great to make this clear in the docs for the future if you would like.