Deploy Aiohttp On Heroku

I have built a simple web server on aiohttp and try to deploy it on heroku, but after deployment I get an error message: at=error code=H14 desc='No web processes running' dyno= c

Solution 1:

Probably aiohttp isn't listening on the right port. You need something like web.run_app(app, port=os.getenv('PORT')).

Update: wait, you're trying to serve it both with gunicorn and with web.run_app which is wrong, you'll need to either just have something like web: python application.py or remove the web.run_app(app).

Solution 2:

If you have an app in myapp.py like so,

import os
from aiohttp import web

#...define routes...async def create_app():
    app = web.Application()
    app.add_routes(routes)
    return app

# If running directly https://docs.aiohttp.org/en/stable/web_quickstart.htmlif __name__ == "__main__":
    port = int(os.environ.get('PORT', 8000))
    web.run_app(create_app(), port=port)

You can run it both locally via the python CLI but also as a worker process managed by gunicorn with a Procfile similar to this:

# use if you wish to run your server directly instead of via an application runner#web: python myapp.py# see https://docs.aiohttp.org/en/stable/deployment.html#nginx-gunicorn#     https://devcenter.heroku.om/articles/python-gunicorn#     http://docs.gunicorn.org/en/latest/run.html
web: gunicorn --bind 0.0.0.0:$PORT -k aiohttp.worker.GunicornWebWorker myapp:create_app