This patch migrates the use of command line 'ip' commands
to pyroute2 library. A new class, 'IpCommand', is created
to wrap the use of the library, implementing the functionalities
needed in this project.
The new wrapper class is defined in 'os_vif' and is used in
'vif_plug_linux_bridge' and 'vif_plug_ovs'.
This patch also adds functional tests in 'os_vif'. The aim
of these functional tests is to check 'pyroute2' implementation
works correctly, by creating, modifying and deleting network
interfaces. 'ip' commands are used to execute additional actions,
not relying on the tested library to check its own results.
Co-Authored-By: Stephen Finucane <stephenfin@redhat.com>
Closes-Bug: #1677238
Change-Id: I18f7b3424a6c447ee89df1f0326ece75f2333bf2
dff9093ab6