Debian Linux – Deploying a Pure Python Web App

start-and-drop-privs.py

#!/usr/bin/env python3.3

HOST_NAME = '::'
PORT_NUMBER = 80

import time
from whatsmyip import HTTPServerV6, RequestHandler

# http://stackoverflow.com/a/2699996/183995
import os, pwd, grp
def drop_privileges(uid_name='nobody', gid_name='nogroup'):
    if os.getuid() != 0:
        # We're not root so, like, whatever dude
        return

    # Get the uid/gid from the name
    running_uid = pwd.getpwnam(uid_name).pw_uid
    running_gid = grp.getgrnam(gid_name).gr_gid

    # Remove group privileges
    os.setgroups([])

    # Try setting the new uid/gid
    os.setgid(running_gid)
    os.setuid(running_uid)

    # Ensure a very conservative umask
    old_umask = os.umask(77)

httpd = HTTPServerV6((HOST_NAME, PORT_NUMBER), RequestHandler)
print(time.asctime(), "Server Starts - %s:%s" % (HOST_NAME, PORT_NUMBER))
drop_privileges('whatsmyip', 'webapp')
try:
    httpd.serve_forever()
except KeyboardInterrupt:
    pass
httpd.server_close()
print(time.asctime(), "Server Stops - %s:%s" % (HOST_NAME, PORT_NUMBER))

start-as-daemon.py

#!/usr/bin/env python

### BEGIN INIT INFO
# Provides:          WhatsMyIP
# Required-Start:    $remote_fs $network
# Required-Stop:     $remote_fs $network
# Should-Start:      $all
# Should-Stop:       $all
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: WhatsMyIP Service in Python
# Description:       WhatsMyIP is a service that returns your
#                    IP address when you query the HTTP server.
#                    https://github.com/pklaus/WhatsMyIP/
### END INIT INFO

import sys, time
from daemon import Daemon

HOST_NAME = '::'
PORT_NUMBER = 8080

# http://stackoverflow.com/a/2699996/183995
import os, pwd, grp
def drop_privileges(uid_name='nobody', gid_name='nogroup'):
    if os.getuid() != 0:
        return
    running_uid = pwd.getpwnam(uid_name).pw_uid
    running_gid = grp.getgrnam(gid_name).gr_gid
    os.setgroups([])
    os.setgid(running_gid)
    os.setuid(running_uid)
    old_umask = os.umask(77)

class MyDaemon(Daemon):
    def run(self):
        from whatsmyip import HTTPServerV6, RequestHandler
        httpd = HTTPServerV6((HOST_NAME, PORT_NUMBER), RequestHandler)
        print time.asctime(), "Server Starts - %s:%s" % (HOST_NAME, PORT_NUMBER)
        
        drop_privileges('whatsmyip', 'webapp')
        
        try:
            httpd.serve_forever()
        except KeyboardInterrupt:
            pass
        httpd.server_close()
        print time.asctime(), "Server Stops - %s:%s" % (HOST_NAME, PORT_NUMBER)
 
if __name__ == "__main__":
    daemon = MyDaemon('/tmp/whatsmyip-daemon.pid')
    if len(sys.argv) == 2:
        if 'start' == sys.argv[1]:
            daemon.start()
        elif 'stop' == sys.argv[1]:
            daemon.stop()
        elif 'restart' == sys.argv[1]:
            daemon.restart()
        else:
            print "Unknown command"
            sys.exit(2)
        sys.exit(0)
    else:
        print "usage: %s start|stop|restart" % sys.argv[0]
        sys.exit(2)