mod_wsgi¶
mod_wsgi is a WSGI server integrated with the Apache httpd server. The modern mod_wsgi-express command makes it easy to configure and start the server without needing to write Apache httpd configuration.
Tightly integrated with Apache httpd.
Supports Windows directly.
Requires a compiler and the Apache development headers to install.
Does not require a reverse proxy setup.
This page outlines the basics of running mod_wsgi-express, not the more complex installation and configuration with httpd. Be sure to read the mod_wsgi-express, mod_wsgi, and Apache httpd documentation to understand what features are available.
Installing¶
Installing mod_wsgi requires a compiler and the Apache server and development headers installed. You will get an error if they are not. How to install them depends on the OS and package manager that you use.
Create a virtualenv, install your application, then install
mod_wsgi
.
$ cd hello-app
$ python -m venv venv
$ . venv/bin/activate
$ pip install . # install your application
$ pip install mod_wsgi
Running¶
The only argument to mod_wsgi-express
specifies a script containing
your application, which must be called application
. You can
write a small script to import your app with this name, or to create it
if using the app factory pattern.
wsgi.py
¶from hello import app
application = app
wsgi.py
¶from hello import create_app
application = create_app()
Now run the mod_wsgi-express start-server
command.
$ mod_wsgi-express start-server wsgi.py --processes 4
The --processes
option specifies the number of worker processes to
run; a starting value could be CPU * 2
.
Logs for each request aren’t show in the terminal. If an error occurs, its information is written to the error log file shown when starting the server.
Binding Externally¶
Unlike the other WSGI servers in these docs, mod_wsgi can be run as root to bind to privileged ports like 80 and 443. However, it must be configured to drop permissions to a different user and group for the worker processes.
For example, if you created a hello
user and group, you should
install your virtualenv and application as that user, then tell
mod_wsgi to drop to that user after starting.
$ sudo /home/hello/venv/bin/mod_wsgi-express start-server \
/home/hello/wsgi.py \
--user hello --group hello --port 80 --processes 4