Question

I am sketching the architecture for a set of programs that share various interrelated objects stored in a database. I want one of the programs to act as a service which provides a higher level interface for operations on these objects, and the other programs to access the objects through that service.

I am currently aiming for Python and the Django framework as the technologies to implement that service with. I’m pretty sure I figure how to daemonize the Python program in Linux. However, it is an optional spec item that the system should support Windows. I have little experience with Windows programming and no experience at all with Windows services.

Is it possible to run a Python programs as a Windows service (i. e. run it automatically without user login)? I won’t necessarily have to implement this part, but I need a rough idea how it would be done in order to decide whether to design along these lines.

Edit: Thanks for all the answers so far, they are quite comprehensive. I would like to know one more thing: How is Windows aware of my service? Can I manage it with the native Windows utilities? What is the equivalent of putting a start/stop script in /etc/init.d?

Answer 1

Yes you can. I do it using the pythoncom libraries that come included with ActivePython or can be installed with pywin32 (Python for Windows extensions).

This is a basic skeleton for a simple service:

import win32serviceutil import win32service import win32event import servicemanager import socket   class AppServerSvc (win32serviceutil.ServiceFramework):     _svc_name_ = 'TestService'     _svc_display_name_ = 'Test Service'      def __init__(self,args):         win32serviceutil.ServiceFramework.__init__(self,args)         self.hWaitStop = win32event.CreateEvent(None,0,0,None)         socket.setdefaulttimeout(60)      def SvcStop(self):         self.ReportServiceStatus(win32service.SERVICE_STOP_PENDING)         win32event.SetEvent(self.hWaitStop)      def SvcDoRun(self):         servicemanager.LogMsg(servicemanager.EVENTLOG_INFORMATION_TYPE,                               servicemanager.PYS_SERVICE_STARTED,                               (self._svc_name_,''))         self.main()      def main(self):         pass  if __name__ == '__main__':     win32serviceutil.HandleCommandLine(AppServerSvc) 

Your code would go in the main() method—usually with some kind of infinite loop that might be interrupted by checking a flag, which you set in the SvcStop method