Python supervise

This module provide a methods to handle runit or daemontools based supervised services, using the control file provided. Here is a small example:

>>> import supervise
>>> s = supervise.Service('test')
>>> print s.status()
{'action': None, 'status': 0, 'uptime': 300L, 'pid': None}
>>> s.start()
>>> print s.status()
{'action': None, 'status': 1, 'uptime': 3L, 'pid': 27450}

Read the manpage of runsv(8) for more information. Also read the documentation for ServiceStatus to known how to parse status information.

History

Last month I needed to install runit in some servers to supervise a couple of services. Unfortunately my management interface cannot handle the services anymore, so I decided to write a small module in python to solve this handicap, and that is the result!.

With this module you can handle in python environment a number of runit scripts. I think that this might be work for daemontools too, but I do not test yet. Let's see an example:

>>> import supervise
>>> c = supervise.Service("/var/service/httpd")
>>> print s.status()
{'action': 'normal', 'status': 'up', 'uptime': 300L, 'pid': None}
>>> if s.status()['status'] == supervise.STATUS_DOWN: print "service down"
service down
>>> s.start()
>>> if s.status()['status'] == supervise.STATUS_UP: print "service up"
service up

Personally I use this module with rpyc library to manage remotely the services running in a host, but it too easy making a web interface, for example using bottle:

import supervise
import simplejson
from bottle import route, run

@route('/service/status/:name')
def service_status(name):
    return simplejson.dumps( supervise.Service("/var/service/" +
        name).status() )

@route('/service/up/:name')
def service_up(name):
    c = supervise.Service("/var/service/" + name)
        c.start()
    return "OK UP"


@route('/service/down/:name')
def service_down(name):
    c = supervise.Service("/var/service/" + name)
        c.down()
    return "OK DOWN"


if __name__ == "__main__":
    run()

Now you can stop your service just only point your browser http://localhost/service/down/httpd (to down http service in this case).

Enjoy!