how to make a python windows service know it's own identity

[Larry Bates]

Chris Curvey wrote:
> On Feb 1, 2:10 pm, Larry Bates <larry.ba... at websafe.com> wrote:
>> Chris Curvey wrote:
>>> Hi all,
>>> I have used the win32com libraries to set up a service called
>>> MyService under Windows.  So far, so good.  Now I need to run multiple
>>> copies of the service on the same machine.  I also have that working.
>>> For monitoring and logging, I'd like each instance of the service to
>>> know it's own identity (MyService1, MyService2, etc.)
>>> But I can't quite seem to grasp how to do this.  In the code below,
>>> the command line parameter "-i" gives the service an identity, but how
>>> do I get the service to understand it's identity when it is started?
>>> Many thanks!
>>> class MyService(win32serviceutil.ServiceFramework):
>>>     """NT Service."""
>>>     _svc_name_ = "MyService"
>>>     _svc_display_name_ = "My Service"
>>>     _id_ = ''
>>>     def SvcDoRun(self):
>>>         provider = MyServiceClass(identifier=self._id_)
>>>         provider.start()
>>>         # now, block until our event is set...
>>>         win32event.WaitForSingleObject(self.stop_event,
>>> win32event.INFINITE)
>>>    # __init__ and SvcStop snipped
>>> ###########################################################################
>>> if __name__ == '__main__':
>>>     import optparse
>>>     parser = optparse.OptionParser()
>>>     parser.add_option("-i", "--identifier", dest="identifier")
>>>     (opts, args) = parser.parse_args()
>>>     if opts.number is not None:
>>>         MyService._svc_name_ += opts.identifier
>>>         MyService._svc_display_name_ += opts.identifier
>>>         MyService._provider_id_ = opts.identifier
>>>     win32serviceutil.HandleCommandLine(MyService,
>>> customInstallOptions="i:")
>> What is your use case for this?  Why not make a single server
>> process multiple providers (store them in a list or other
>> container)?
>>
>> -Larry Bates
> 
> The use case is that I have a queue of jobs that need to run.  My
> service connects to a central "distributor" server, which hands out
> jobs to complete.  I'd like to be able to run multiple copies of the
> distributed service so that I can make the most use of each machine
> where they run.  (I'm not certain of the thread safety of some of the
> libraries I'm using, so I'm leery of going the multi-threaded route)
> Anyway, when my service gets a job to process, I'd like to know which
> copy of the service is working on which job.  So I want my log
> messages to look like this:
> 
> Job 123:  Host: alpha  Service: MyService A
> Job 124:  Host: alpha  Service: MyService B
> Job 124:  Host: beta  Service: MyService C
> 
> Is that clear, or have I muddied the waters?
> 
Ok, makes more sense now.  You will be running each service on a different
computer.  If I'm understanding all you need is to supply an attribute
to the service that represents its internal name (the one you will use
to do the logging).  If I wanted to do this I would create a .INI file
and read it (using ConfigParser) during service class __init__ method.
Assign self.servicename=<value from .INI file>.  Then use self.servicename
to do my logging.  I have a service somewhat like you describe and this
works fine for me.

-Larry