Firebase from Flask deployment server - apache

Question

in development mode with Flask, I am successfully able to read and write data to Firestore using the firebase admin module. However, once I deploy the app on Apache 2 using mod_wsgi, everything works fine (firebase app initialization doesn't throw any error) until I start getting a document, where the code gets stuck and the page loads forever.
Flask function where the problem occurs in __init__.py:
#app.route('/users/<user>')
def login(user=None):
if not user:
abort(404)
userRef = db.collection('users').document(user)
print("1") # This runs.
userDoc = userRef.get() # The code gets stuck here. No error message is ever returned or stored in the error log.
print("2") # This never runs.
flaskapp.wsgi
#!/usr/local/bin/python3.8
import sys
import os
import logging
logging.basicConfig(stream=sys.stderr)
os.chdir("/var/www/html/example.com/FlaskApp/")
sys.path.insert(0,"/var/www/html/example.com/FlaskApp/")
from __init__ import app as application
example.com.conf
LoadModule wsgi_module "/home/username/.local/lib/python3.8/site-packages/mod_wsgi/server/mod_wsgi-py38.cpython-38-x86_64-linux-gnu.so"
WSGIPythonHome "/usr/local"
<VirtualHost *:80>
# Admin email, Server Name (domain name), and any aliases
ServerAdmin username#example.com
ServerName example.com
ServerAlias www.example.com
# Index file and Document Root (where the public files are located)
DirectoryIndex index.html index.php
DocumentRoot /var/www/html/example.com/public_html
WSGIScriptAlias / /var/www/html/example.com/FlaskApp/flaskapp.wsgi
<Directory /var/www/html/example.com/FlaskApp/>
Require all granted
</Directory>
Alias /static /var/www/html/example.com/FlaskApp/static
<Directory /var/www/html/example.com/FlaskApp/static/>
Require all granted
</Directory>
# Log file locations
LogLevel warn
ErrorLog /var/www/html/example.com/log/error.log
CustomLog /var/www/html/example.com/log/access.log combined
</VirtualHost>
Do you know how to make Firebase get() works in a deployed Flask app? Thank you for your help!

Answer 1

Seems like WSGI needs to be forced to use the main Python interpreter. Therefore, you'll need to add application-group=%{GLOBAL} to the end of your ``WSGIScriptAlias line on example.com.conf, so that the line now reads:
WSGIScriptAlias / /var/www/html/example.com/FlaskApp/flaskapp.wsgi application-group=%{GLOBAL}
After that, restart Apache with the terminal command systemctl restart apache and your problem should be solved.