Replace mnexec with unshare(1)?

[ghost]

There's nothing specific on this question in Github issue history or git log -Gunshare. The outcome of this ticket would be replacing mnexec with unshare(1) (ubuntu util-linux) or a comment in mnexec.c why it's insufficient for mininet. Removing the C compiler dependency would be nice.

[cheriimoya]

this is actually really interesting, by running unshare -n -c bash and then ip l i only see the loopback interface, this might work somehow...
do you have any opinion on this @lantz ?

[lantz]

Yes,

1. unshare didn't work properly when mininet was developed, and it was also missing from ubuntu.
2. mnexec has additional features that unshare doesn't support, including pid output and attaching to an existing namespace. However we might be able to finesse this by a) explicitly printing the pid and b) using ip nsenter or ip netns exec.