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Psycopg / asyncio set even loop policy

Hope you're well!
I have a problem with the Psycopg module allowing to interact with the PostgreSQL database.
When I start my HTTP server (I use FastAPI and Uvicorn) normally, and I send a request to my server, I have this error:
error connecting in 'pool-1': Psycopg cannot use the 'ProactorEventLoop' to run in async mode. Please use a compatible event loop, for instance by setting 'asyncio.set_event_loop_policy(WindowsSelectorEventLoopPolicy())'
I have already done what the error solution suggests, that is, set the event loop policy to WindowsSelectorEventLoopPolicy, which I did.
import asyncio
from asyncio import WindowsSelectorEventLoopPolicy
asyncio.set_event_loop_policy(WindowsSelectorEventLoopPolicy())
I put this line in my main file (which is the central file of my app)
But still nothing, I still have the same error when I send a request to my server.
But what is strange is that when I start my server with the --reload option (which is used to reload the files automatically in case of modification but is not adapted for production, according to the documentation of Uvicorn/FastAPI), I have no error when I send my requests and everything goes correctly
Can you tell me what is the cause of the problem and how to solve it?
P.S: Here is how i start my HTTP from Windows Powershell
Here is how I start my HTTP server normally (which doesn't works)
uvicorn src.main:app --port 2314
Here is how I start my HTTP server with the --reload option (which works perfectly)
uvicorn src.main:app --port 2314 --reload

Uvicorn sets the WindowsSelectorEventLoopPolicy policy when using the reload option and Windows by default, otherwise it doesn't. That's why you are facing this mismatch behavior.
Changing another policy should have worked, maybe it's misplaced.
The below works:
import asyncio
import uvicorn
asyncio.set_event_loop_policy(asyncio.DefaultEventLoopPolicy())
async def app(scope, receive, send):
print(asyncio.get_event_loop_policy())
if __name__ == "__main__":
uvicorn.run("main:app", port=8010)
If we remove the line on which we set the policy, and we have uvloop installed (uvicorn automatically selects uvloop if installed), we can see that the uvloop policy is printed.
In case it's not misplaced, I recommend open a discussion on uvicorn.
Disclaimer: I'm a maintainer of Uvicorn.

Thank you! After having made several tests and having read again the documentation of uvicorn.
Everything was a little bit my fault
I launched the uvicorn HTTP server (without the --reload option) directly from the command line from a terminal (in my case Powershell), I got the error.
error connecting in 'pool-1': Psycopg cannot use the 'ProactorEventLoop' to run in async mode. Please use a compatible event loop, for instance by setting 'asyncio.set_event_loop_policy(WindowsSelectorEventLoopPolicy())'
Because this way of doing things didn't read the import I had done in my main.py file, but simply started the server without caring about anything, hence the error asking me to set the event loop policy to WindowsSelectorEventLoopPolicy (which I had done), simply because the import line defining my event loop policy was never reached.
So now instead of launching my uvicorn server directly in the terminal like this
uvicorn src.main:app --port 2314
I execute my python code like this
python -m src.main
and I had to modify my code in main.py like this
import asyncio
from asyncio import WindowsSelectorEventLoopPolicy
import uvicorn
from fastapi import FastAPI
...
asyncio.set_event_loop_policy(WindowsSelectorEventLoopPolicy())
app = FastAPI()
...
if __name__ == '__main__':
uvicorn.run('src.main:app', host="127.0.0.1", port=2314)
The reason why it was working without any problem in the terminal is by running my HTTP server with the --reload option like this
uvicorn src.main:app --port 2314 --reload
is that as #marcelo-trylesinski said, the --reload option automatically sets event loop to WindowsSelectorEventLoopPolicy. I wish this could be notified / mentioned in the documentation.
Thanks again to #marcelo-trylesinski for his help

Deploying flask app on cpanel, INTERNAL SERVER ERROR when changing requesting other than base url

I want to deploy my flask-restx application on a shared hosting. Since I am beginner in deployment, I followed a video tutorial from youtube.
I did step by step by following this tutorial.
For those who do not want to go through the tutorial, I am writing the steps:
I created an application from the Python cPanel
Initial set up in Cpanel
Then I opened terminal and changed my venv and installed flask by "pip install flask"
Project Structure
filas_folder/
├──public
├──tmp
│ └──restart.txt
├──app.py
└──passenger_wsgi.py
app.py looks like
from flask import Flask
app = Flask(__name__)
#app.route("/")
def main_():
return "flask is running"
#app.route("/user")
def main_2():
return "user is running"
if __name__ == "__main__": app.run()
Restart app from cpanel
passenger.py looks like
import imp
import os
import sys
sys.path.insert(0, os.path.dirname(__file__))
wsgi = imp.load_source('wsgi', 'app.py')
application = wsgi.app
when I open www.example.com
flask is running
But when I open www.example.com/user
Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator at webmaster#example.com to inform them of the time this error occurred, and the actions you performed just before this error.
More information about this error may be available in the server error log.
Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.
My system has cloudlinux and uses apache server. This is not the first deployment. Many wordpress and static websites are running on the server.
I opened apache logs at /usr/local/apache/logs/error_log
I get the error "Request exceeded the limit of 10 internal redirects due to probable configuration error. Use 'LimitInternalRecursion' to increase the limit if necessary. Use 'LogLevel debug' to get a backtrace., referer" http://example.com/user"

Add the following to the top of your .htaccess file:
RewriteEngine on
RewriteRule ^http://%{HTTP_HOST}%{REQUEST_URI} [END,NE]
Got this info from: https://stackoverflow.com/a/63971427/10122266

"Stackdriver Debugger is not set up for the python runtime on GAE Flex" Warning

I'm attempting to debug a Flask/Python app running on Google Appengine flexible environment.
However, I see a warning message within the Stackdriver Debug interface in Google Console, and am unable to set any breakpoints.
The warning reads:
Stackdriver Debugger is not set up for the python runtime on GAE Flex
Screenshot of warning
Any thoughts on what I'm doing wrong?
I've:
Enabled the Stackdriver Debugger API (as mentioned here)
Imported and initialised the Debugger (following the instructions here)
Included google-python-cloud-debugger in requirements.txt
main.py (the app entry point defined in app.yaml)
from werkzeug.serving import run_simple
from werkzeug.wsgi import DispatcherMiddleware
from wsgi import api, frontend, manage
try:
import googleclouddebugger
googleclouddebugger.AttachDebugger()
except ImportError:
pass
app = DispatcherMiddleware(frontend.create_app(), {
'/api': api.create_app(),
'/manage': manage.create_app()
})
if __name__ == '__main__':
run_simple('0.0.0.0', 5000, app, use_reloader=True, use_debugger=True)
app.yaml
runtime: python
env: flex
entrypoint: gunicorn -b :$PORT main:app
runtime_config:
python_version: 2
manual_scaling:
instances: 1
resources:
cpu: 1
memory_gb: 0.5
disk_size_gb: 10
env_variables:
SQLALCHEMY_DATABASE_URI: "postgresql+psycopg2://myusername:mypassword!#/instancename?host=/cloudsql/instancename"
beta_settings:
cloud_sql_instances: "instancename"
Update 1
After a comment and noticing a urllib import error, I wondered if the wsgi nature of my application was causing issues. I went back to the documentation, saw a note about Django framework doing something similar and changed the following:
googleclouddebugger.AttachDebugger()
to
googleclouddebugger.enable()
This got rid of the urllib import error, but hasn't resolved the overall issue.

I don't see anything wrong with this configuration, but here are some suggestions:
Once you open the GCP Console Debug page, please make sure you selected the correct version of the app from the top dropdown menu before starting the debugging session. It may be pointing to an old app version that is not debuggable, or the page and the dropdown might need a refresh to display the latest version.
Similarly, please check if your Stackdriver stderr logs contains a line that like this:
2017-12-24 15:14:14.000 PST I1224 23:14:14.600462 12 gcp_hub_client.py:335] Debuggee registered successfully, ID: gcp:1025611681465:7144dac417e43025
This means the debugger is actually setup/working properly, and most likely indicates that the UI is requires a refresh or selecting the right app version from the dropdown.
Make sure you have the google-python-cloud-debugger in the requirements.txt file.
Consider adding a simple print statement in the try/except block for the debugger, as folllows:
...
except ImportError as e:
print 'Failed to import Google Cloud Debugger: %s' % str(e)
pass
Then, check the stderr logs on Stackdriver Logging to see if this printed any exceptions.
I don't know about werkzeug, but you might want to try disabling the default debugger there by passing use_debugger=False, just to avoid possible conflicts.
Try deploying a simpler flask app (e.g., start with the hello world for Flex from here but modify it to use python_version: 2) and see if the debugger works for you there.

How to run python websocket on gunicorn

I found this 0 dependency python websocket server from SO: https://gist.github.com/jkp/3136208
I am using gunicorn for my flask app and I wanted to run this websocket server using gunicorn also. In the last few lines of the code it runs the server with:
if __name__ == "__main__":
server = SocketServer.TCPServer(
("localhost", 9999), WebSocketsHandler)
server.serve_forever()
I cannot figure out how to get this websocketserver.py running in gunicorn. This is because one would think you would want gunicorn to run server_forever() as well as the SocketServer.TCPServer(....
Is this possible?

GUnicorn expects a WSGI application (PEP 333) not just a function. Your app has to accept an environ variable and a start_response callback and return an iterator of data (roughly speaking). All the machinery encapsuled by SocketServer.StreamRequestHandler is on gunicorn side. I imagine this is a lot of work to modify this gist to become a WSGI application (But that'll be fun!).
OR, maybe this library will get the job done for you: https://github.com/CMGS/gunicorn-websocket

If you use Flask-Sockets extension, you have a websocket implementation for gunicorn directly in the extension which make it possible to start with the following command line :
gunicorn -k flask_sockets.worker app:app
Though I don't know if that's what you want to do.

AssertionError: No api proxy found for service "xmpp"

I am trying to run gae app without dev_appserver.py, and have following error
AssertionError: No api proxy found for service "xmpp"
room = webrtc.Room.get_by_key_name(room_key)
I found in the app.yaml inbound_services:
- channel_presence
How to enable channel_presence directly in application.py

Unless otherwise specified, libraries included with the App Engine SDK are expected only to work within the App Engine environment. You cannot just import the XMPP library included with the App Engine SDK and expect it to work in a non-GAE application.