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.
Feel free to join us in #gunicorn on freenode.
Gunicorn requires Python 2.x >= 2.6 or Python 3.x >= 3.1.
Install from sources:
$ python setup.py install
Or from Pypi:
$ pip 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. If you're on Python 3 you may also consider one othe Asyncio workers. Check out the FAQ for more information on when you'll want to consider one of the alternate worker types.
To install eventlet:
$ pip install -U eventlet
If you encounter errors when compiling the extensions for Eventlet or Gevent you most likely need to install a newer version of libev or libevent.
After installing Gunicorn you will have access to the command line script
gunicorn.
-c CONFIG, --config=CONFIG- Specify the path to a config file or python module.
-b BIND, --bind=BIND- Specify a server socket to bind. Server sockets can be any of$(HOST),$(HOST):$(PORT), orunix:$(PATH). An IP is a valid$(HOST).
-w WORKERS, --workers=WORKERS- The number of worker processes. This number should generally be between 2-4 workers per core in the server. Check the FAQ for ideas on tuning this parameter.
-k WORKERCLASS, --worker-class=WORKERCLASS- The type of worker process to run. You'll definitely want to read the production page for the implications of this parameter. You can set this toegg:gunicorn#$(NAME)where$(NAME)is one ofsync,eventlet,gevent, ortornado,gthread,gaiohttp`. ``syncis 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 likepsandtop).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 serve '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
We also provide integration for both Django and Paster applications.
gunicorn just needs to be called with a the location of a WSGI application object.:
gunicorn [OPTIONS] APP_MODULE
Where APP_MODULE is of the pattern MODULE_NAME:VARIABLE_NAME. The module name should be a full dotted path. The variable name refers to a WSGI callable that should be found in the specified module.
So for a typical Django project, invoking gunicorn would look like:
gunicorn myproject.wsgi:application
(This requires that your project be on the Python path; the simplest way to ensure that is to run this command from the same directory as your manage.py file.)
You can use the --env option to set the path to load the settings. In case you need it you can also add your application path to PYTHONPATH using the --pythonpath option.
If you are a user/developer of a paste-compatible framework/app (as Pyramid, Pylons and Turbogears) you can use the gunicorn --paste option to run your application.
For example:
gunicorn --paste development.ini -b :8080 --chdir /path/to/project
It is all here. No configuration files nor additional python modules to write !!
Gunicorn provides an optional instrumentation of the arbiter and workers using the statsD protocol over UDP. Thanks to the gunicorn.instrument.statsd module, Gunicorn becomes a statsD client The use of UDP cleanly isolates Gunicorn from the receiving end of the statsD metrics so that instrumentation does not cause Gunicorn to be heldeup by a slow statsD consumer.
To use statsD, just tell gunicorn where the statsD server is:
$ gunicorn --statsd-host=localhost:8125 ...
The Statsd logger overrides gunicorn.glogging.Logger to track all requests. The following metrics are generated:
gunicorn.requests: request rate per secondgunicorn.request.duration: histogram of request durationgunicorn.workers: number of workers managed by the arbiter (gauge)gunicorn.log.critical: rate of critical log messagesgunicorn.log.error: rate of error log messagesgunicorn.log.warning: rate of warning log messagesgunicorn.log.exception: rate of exceptional log messages
To generate new metrics you can log.info with a few additional keywords:
log.info("...", extra={"metric": "my.metric", "value": "1.2", "mtype": "gauge"})
Gunicorn is released under the MIT License. See the LICENSE file for more details.