Proper way to handle errors from python restorecon binding?

[Brian J. Murrell]

It's not clear to me in which ways the restorecon() python binding can return an error/failure?

Can it raise an exception or does it always simply report errors in it's return code? I.e. I need to do:

rc = selinux.restorecon(path)
if rc != 0:
    [error handling]

And/or do I need a try/except block around restorecon() as something it calls could raise an exception?

I have seen reference to code that calls it as such:

try:
    selinux.restorecon(path)
except selinux.SELinuxError:
    [error handling]

[Petr Lautrbach]

"Brian J. Murrell"  writes:
> It's not clear to me in which ways the restorecon() python binding can return an error/failure?
>
> Can it raise an exception or does it always simply report errors in it's return code? I.e. I need to do:
>
> rc = selinux.restorecon(path)
> if rc != 0:
>     [error handling]
>
> And/or do I need a try/except block around restorecon() as something it calls could raise an exception?
>
> I have seen reference to code that calls it as such:
>
> try:
>     selinux.restorecon(path)
> except selinux.SELinuxError:
>     [error handling]

selinux.restorecon() is a python swig wrapper around
selinux_restorecon_parallel() which is a generated libselinux python
binding:

https://github.com/SELinuxProject/selinux/blob/main/libselinux/src/selinuxsw...
https://github.com/SELinuxProject/selinux/blob/main/libselinux/src/selinuxsw...

Based on this, you need to use try/except block around selinux.restorecon() if
you want to handle errors.
> > > import selinux
> > > selinux.restorecon('/root/ahoj')

lstat(/var/roothome/ahoj) failed: Permission denied
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib64/python3.12/site-packages/selinux/__init__.py", line 93, in restorecon
    selinux_restorecon_parallel(os.path.expanduser(path), restorecon_flags, nthreads)
  File "/usr/lib64/python3.12/site-packages/selinux/__init__.py", line 451, in selinux_restorecon_parallel
    return _selinux.selinux_restorecon_parallel(pathname, restorecon_flags, nthreads)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
PermissionError: [Errno 13] Permission denied