WSGI HTTP Server for UNIX
Gunicorn ‘Green Unicorn’ is a Python WSGI HTTP Server for UNIX. It’s a pre-fork worker model ported from Ruby’s Unicorn project. The Gunicorn server is broadly compatible with various web frameworks, simply implemented, light on server resource usage, and fairly speedy.
Gunicorn requires Python 2.x >= 2.6 or Python 3.x >= 3.1.
Install from sources:
$ python setup.py install
Or from Pypi:
$ easy_install -U gunicorn
You may also want to install Eventlet or Gevent if you expect that your application code may need to pause for extended periods of time during request processing. Check out the FAQ for more information on when you’ll want to consider one of the alternate worker types.
To install eventlet:
$ easy_install -U eventlet
After installing Gunicorn you will have access to three command line scripts that can be used for serving the various supported web frameworks: gunicorn, gunicorn_django, and gunicorn_paster.
Commonly Used Arguments
-c CONFIG, --config=CONFIG - Specify the path to a config file
-b BIND, --bind=BIND - Specify a server socket to bind. Server sockets can be any of $(HOST), $(HOST):$(PORT), or unix:$(PATH). An IP is a valid $(HOST).
-w WORKERS, --workers=WORKERS - The number of worker processes. This number should generally be between 2-4 workers per core in the server. Check the FAQ for ideas on tuning this parameter.
-k WORKERCLASS, --worker-class=WORKERCLASS - The type of worker process to run. You’ll definitely want to read the production page for the implications of this parameter. You can set this to egg:gunicorn#$(NAME) where $(NAME) is one of sync, eventlet, gevent, or tornado. sync is the default.
-n APP_NAME, --name=APP_NAME - If setproctitle is installed you can adjust the name of Gunicorn process as they appear in the process system table (which affects tools like ps and top).
sync=gunicorn.workers.sync:SyncWorker eventlet=gunicorn.workers.geventlet:EventletWorker gevent=gunicorn.workers.ggevent:GeventWorker tornado
There are various other parameters that affect user privileges, logging, etc. You can see the complete list with the expected:
$ gunicorn -h
The first and most basic script is used to server ‘bare’ WSGI applications that don’t require a translation layer. Basic usage:
$ gunicorn [OPTIONS] APP_MODULE
Where APP_MODULE is of the pattern $(MODULE_NAME):$(VARIABLE_NAME). The module name can be a full dotted path. The variable name refers to a WSGI callable that should be found in the specified module.
Example with test app:
$ cd examples $ gunicorn --workers=2 test:app
You might not have guessed it, but this script is used to server Django applications. Basic usage:
$ gunicorn_django [OPTIONS] [SETTINGS_PATH]
By default SETTINGS_PATH will look for settings.py in the current directory.
Example with your Django project:
$ cd path/to/yourdjangoproject $ gunicorn_django --workers=2
Alternatively, you can install some Gunicorn magic directly into your Django project and use the provided command for running the server.
First you’ll need to add gunicorn to your INSTALLED_APPS in the settings file:
INSTALLED_APPS = ( ... "gunicorn", )
Then you can run:
python manage.py run_gunicorn
Yeah, for Paster-compatible frameworks (Pylons, TurboGears 2, …). We apologize for the lack of script name creativity. And some usage:
$ gunicorn_paster [OPTIONS] paste_config.ini
$ cd yourpasteproject $ gunicorn_paster --workers=2 development.ini
If you’re wanting to keep on keeping on with the usual paster serve command, you can specify the Gunicorn server settings in your configuration file:
[server:main] use = egg:gunicorn#main host = 127.0.0.1 port = 5000
And then as per usual:
$ cd yourpasteproject $ paster serve development.ini workers=2
Gunicorn paster from script
If you’d like to run Gunicorn paster from a script instead of the command line (for example: a runapp.py to start a Pyramid app), you can use this example to help get you started:
import os import multiprocessing from paste.deploy import appconfig, loadapp from gunicorn.app.pasterapp import paste_server if __name__ == "__main__": iniFile = 'config:development.ini' port = int(os.environ.get("PORT", 5000)) workers = multiprocessing.cpu_count() * 2 + 1 worker_class = 'gevent' app = loadapp(iniFile, relative_to='.') paste_server(app, host='0.0.0.0', port=port, workers=workers, worker_class=worker_class)
Gunicorn is released under the MIT License. See the LICENSE file for more details.
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