pkgcore/snakeoil

Child process ID

Elbert-Tardis opened this issue · 4 comments

Elbert-Tardis commented

Hi!

I'm using the SplitExec class (or actually pychroot.Chroot does) to setup a jail. To do this i've subclassed pychroot.Chroot and overruled the _parent_setup() method, which is called from the __enter__() method as shown below.

What i need to do is setup a pair of veth interfaces and move one of them to the network namespace of the jail. I want to do this based upon the process ID. Something like:

   ip link add veth0 type veth peer name veth1
   ip link set veth0 netns <process ID>

However, the childpid attribute is set right after the call to _parent_setup() so i cannot use it from this method. Is there a reason why the childpid attribute is initialized after the call? Or would it be possible to swap the two statements?

Kind regards,

Elbert

def __enter__(self):
        parent_pipe, child_pipe = Pipe()
        childpid = os.fork()

        if childpid != 0:
==>          self._parent_setup()
==>          self.childpid = childpid
radhermit commented

No, there's no reason I can think of for that ordering, probably just got overlooked.

Elbert-Tardis commented

Thanks a lot!

radhermit commented

I tossed out a 0.8.2 release for you that has this fix.

Elbert-Tardis commented

Once again: Thank you very much!

Kind regards,

Elbert