gnt_cluster.py: unit test for usermode helper

[ganeti-local] / test / data / ip-addr-show-dummy0.txt

7: dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN
    link/ether 06:d2:06:24:99:dc brd ff:ff:ff:ff:ff:ff
    inet 192.0.2.1/32 scope global dummy0
    inet6 2001:db8:85a3::8a2e:370:7334/128 scope global
       valid_lft forever preferred_lft forever