Can I run a Python script as a service?

Question

Is it possible to run a Python script as a background service on a webserver? I want to do this for socket communication.

Answer 1

on XP and later you can use the sc.exe program to use any .exe as service:

>sc create
Creates a service entry in the registry and Service Database.
SYNTAX:
sc create [service name] [binPath= ] <option1> <option2>...
CREATE OPTIONS:
NOTE: The option name includes the equal sign.
 type= <own|share|interact|kernel|filesys|rec>
       (default = own)
 start= <boot|system|auto|demand|disabled>
       (default = demand)
 error= <normal|severe|critical|ignore>
       (default = normal)
 binPath= <BinaryPathName>
 group= <LoadOrderGroup>
 tag= <yes|no>
 depend= <Dependencies(separated by / (forward slash))>
 obj= <AccountName|ObjectName>
       (default = LocalSystem)
 DisplayName= <display name>
 password= <password>

You can start your pythonscript by starting the python interpreter with your script as argument:

python.exe myscript.py

Answer 2

You can make it a daemon. There is a PEP for a more complete solution, but I have found that this works well.

import os, sys

def become_daemon(our_home_dir='.', out_log='/dev/null', err_log='/dev/null', pidfile='/var/tmp/daemon.pid'):
    """ Make the current process a daemon.  """

    try:
        # First fork
        try:
            if os.fork() > 0:
                sys.exit(0)
        except OSError, e:
            sys.stderr.write('fork #1 failed" (%d) %s\n' % (e.errno, e.strerror))
            sys.exit(1)

        os.setsid()
        os.chdir(our_home_dir)
        os.umask(0)

        # Second fork
        try:
            pid = os.fork()
            if pid > 0:
                # You must write the pid file here.  After the exit()
                # the pid variable is gone.
                fpid = open(pidfile, 'wb')
                fpid.write(str(pid))
                fpid.close()
                sys.exit(0)
        except OSError, e:
            sys.stderr.write('fork #2 failed" (%d) %s\n' % (e.errno, e.strerror))
            sys.exit(1)

        si = open('/dev/null', 'r')
        so = open(out_log, 'a+', 0)
        se = open(err_log, 'a+', 0)
        os.dup2(si.fileno(), sys.stdin.fileno())
        os.dup2(so.fileno(), sys.stdout.fileno())
        os.dup2(se.fileno(), sys.stderr.fileno())
    except Exception, e:
        sys.stderr.write(str(e))

Answer 3

There is the very helpful Pypi package which is the basis for my daemons written in Python.

Answer 4

If you are talking about linux, it is as easy as doing something like ./myscript.py &

Answer 5

Assuming this is for Windows, see this recipe based on srvany

Answer 6

You might want to check out Twisted.