win32serviceutil does not respect <_exe_name_>

[pythoniac]

I have successfully installed a python service for windows with a call to <win32serviceutil.HandleCommandLine>. It did copy the "pythonservice.exe" from the user site-lib to the python install folder (my case: "C:\Program Files\Python311"). When I tried to install another service onto the same machine I got the error that the "pythonservice.exe" could not be copied since it already existed in the target folder. I have set the "exe_name="DatenloggerDienst.exe"" in my class and traced its way through the code in win32serviceutil. It gets passed correctly to the "LocatePythonServiceExe" method as parameter named "exe" and I noted that on line 41 it gets overwritten by

exe = f"pythonservice{suffix}.exe" - so "exe" is "pythonservice.exe" from here on

and then the "correct" variable gets to hold the value

correct = os.path.join(sys.exec_prefix, exe)

After which a copy action is taken in the form of

print(f"moving host exe '{maybe}' -> '{correct}'")

Of course this fails as I have already a "pythonservice.exe" in the target location. Once I changed it, so that "correct" holds the Name I have given in my class ("exe_name" Parameter) it just works (i.e.: "pythonservice.exe" is copied from the user site-lib to the Python install folder with the new name "DatenloggerDienst.exe")

Maybe I am missing something here?! From my understanding, every new service gets a new file and the name of the file should be "exe_name" or - if this is not given "pythonservice.exe".

Thanks for having a look.

[mhammond]

and I noted that on line 41 it gets overwritten by

The comment just a few lines up says "# We are confused if we aren't now looking for our default." - so yeah, that code's confused. The rest of that code is trying to work around pip packaging issues, where pythonservice.exe can't be installed in a place where it can be used.

We only get to that if not os.path.isfile("DatenloggerDienst.exe") - in your scenario, how would that code locate the full path name to your executable? Should we just check os.path.join(sys.exec_prefix, exe)? (ie, is that executable already in your sys.exec_prefix?

[pythoniac]

Thanks for the swifty reply. I assume I am not qualified to suggest a "proper" way of handling things because I am completely unaware of all the dirty pitfalls that your code obviously needs to maneuver around. Maybe it is helpful if I share my changed two lines here (marked with "MY CHANGE" 01 and 02?!) that results in doing the copy action successfully (full paths here for clarity):

copying host exe 'C:\Users\fabian_admin\AppData\Roaming\Python\Python311\site-packages\win32\pythonservice.exe' -> 'C:\Program Files\Python311\DatenloggerDienst.exe'

I could now happily install any other Python script as a Windows Service, provided I always give my class a different exe_name (still assuming that every service needs its own .exe file).

Code here:

`def LocatePythonServiceExe(exe=None):

# MY CHANGE 01
fab_exe = exe
# -------------

if not exe and hasattr(sys, "frozen"):
    # If py2exe etc calls this with no exe, default is current exe,
    # and all setup is their problem :)
    return sys.executable

if exe and os.path.isfile(exe):
    return win32api.GetFullPathName(exe)

# We are confused if we aren't now looking for our default. But if that
# exists as specified we assume it's good.
exe = f"pythonservice{_d}.exe"
if os.path.isfile(exe):
    return win32api.GetFullPathName(exe)

# Now we are searching for the .exe
# We are going to want it here.

# MY CHANGE 02
correct = os.path.join(sys.exec_prefix, fab_exe)
# -------------

# Even if that file already exists, we copy the one installed by pywin32
# in-case it was upgraded.
# pywin32 installed it next to win32service.pyd (but we can't run it from there)
maybe = os.path.join(os.path.dirname(win32service.__file__), exe)
if os.path.exists(maybe):
    print(f"copying host exe '{maybe}' -> '{correct}'")
    win32api.CopyFile(maybe, correct)

`