[SOLVED] Flask-Caching use UWSGI cache with NGINX

Flask-Caching use UWSGI cache with NGINX

The UWSGI is connected to the flask app per UNIX-Socket:

NGINX (LISTEN TO PORT 80) <-> UWSGI (LISTER PER UNIX-SOCKER) <-> FLASK-APP

I have initalized a uwsgi cache to handle global data. I want to handle the cache with python package flask-caching.

I am trying to init the Cache-instance with the correct cache address. There seems to be something wrong. I think, that the parameters for app.run() are not relevant for uwsgi.

If I am setting a cache entry, it return always None:

app.route("/")
def test():
    cache.set("test", "OK", timeout=0)
    a = cache.get("test")
    return a

main.py

from flask import Flask
from flask_caching import Cache

app = Flask(__name__)
# Check Configuring Flask-Caching section for more details
cache = Cache(app, config={'CACHE_TYPE': 'uwsgi', 'CACHE_UWSGI_NAME':'mycache@localhost'})

if __name__ == "__main__":
    app.run(host="0.0.0.0", port=5000)

uwsgi.ini

[uwsgi]
module = main
callable = app
cache2 = name=mycache,items=100

nginx.conf

server {
    listen 80;
    location / {
        try_files $uri @app;
    }
    location @app {
        include uwsgi_params;
        uwsgi_pass unix:///tmp/uwsgi.sock;
    }
    location /static {
        alias /app/testapp/static;
    }
}

I am working with the docker build from https://github.com/tiangolo/uwsgi-nginx-flask-docker. The app is working, expect the cache.

Solution

Be aware of using of spawning multiple processes for NGINX. Every process handles its own cache. Without an additional layer, it is not possible to access to a cache from different nginx process.

_{This answer was posted as an edit to the question Flask-Caching use UWSGI cache with NGINX by the OP ewro under CC BY-SA 4.0.}