Notify call no more working in 0.9.4 and newer with fastapi events

[stefapi]

try this sample application:

# services/users/project/try_fail.py

import uvicorn
import apprise
from fastapi import FastAPI

app = FastAPI(
    title="apprise_failure",
    description="A sample",
)

@app.on_event("startup")
def system_startup():
        apobj = apprise.Apprise()
        apobj.notify(body = "Application Startup", title = "startup failed")
        print("passed !")


def main():
    uvicorn.run(
        "try_fail:app",
        host="0.0.0.0",
        port=9000,
        reload=True,
        reload_dirs=["."],
        debug=True,
        log_level='debug',
        log_config=None,
        workers=1,
        forwarded_allow_ips="*",
    )

if __name__ == "__main__":
    main()

This application works well with apprise 0.9.3 but does not work anymore with 0.9.4 and more recent versions.
You may use any recent version of fastapi and uvicorn.

[caronc]

Hmm, I'm stumped with this one; i'd be open to any advice here from anyone else. I can certainly reproduce the problem, but nothing changed with the asyncio that I can see that would be related. If anything there is something new introduced in fastapi.

This is definitely a good bug.... 😕

python ../try_fail.py

Produces:

Traceback (most recent call last):
  File "/home/l2g/Development/apprise-api/lib64/python3.10/site-packages/apprise/py3compat/asyncio.py", line 67, in tosync
    return asyncio.run(cor, debug=debug)
  File "/usr/lib64/python3.10/asyncio/runners.py", line 33, in run
    raise RuntimeError(
RuntimeError: asyncio.run() cannot be called from a running event loop

I need a try/catch block around here. However when a loop is already running, i can't seem to find any good documentation on how to execute the coroutine in a blocking state so we can get the response. There seems to be reference to getting the nest-asyncio library to help. I'm not sure here...

Maybe @YoRyan has an idea here?

[caronc]

As an update, this seems to work:

# services/users/project/try_fail.py

import uvicorn
import apprise
from fastapi import FastAPI
import nest_asyncio

app = FastAPI(
    title="apprise_failure",
    description="A sample",
)

@app.on_event("startup")
def system_startup():
        apobj = apprise.Apprise()
        apobj.notify(body = "Application Startup", title = "startup failed")
        print("passed !")


def main():
    nest_asyncio.apply()
    uvicorn.run(
        "try_fail:app",
        host="0.0.0.0",
        port=9000,
        reload=True,
        reload_dirs=["."],
        debug=True,
        log_level='debug',
        log_config=None,
        workers=1,
        forwarded_allow_ips="*",
    )

if __name__ == "__main__":
    main()

I only added 2 lines after running the following:

 pip install nest-asyncio

1. First just the import itself at the head of the file (in your example)

   import nest_asyncio

2. Then the following was added in the main() call area (at the start)

   nest_asyncio.apply()

[caronc]

I see you changed the title 9hrs, ago. Were you able to try my modification to your sample code? That may resolve your issue.

[stefapi]

Hi.
Yes, it now works on the target application. No more issue faced. It will be great to share this workaround in the documentation for the whole community.
Thx !

[caronc]

It will be great to share this workaround in the documentation for the whole community.

Great idea!

I added a section here in Troubleshooting and also beefed up the documentation a bit here to explain how you can also leverage async_notify() if one chooses to.

This should address your documentation request? Thoughts?

[stefapi]

yes, perfect ! thx to you

[YoRyan]

If a framework has its own async event loop, it should also accept async handlers. So this works without requiring nest_asyncio:

@app.on_event("startup")
async def system_startup():
        apobj = apprise.Apprise()
        await apobj.async_notify(body = "Application Startup", title = "startup failed")
        print("passed !")

It's a shame we've broken existing code, but fortunately, the fix should be simple: If running in an existing event loop, switch to the new async_notify() method.