30-maas-01-bmc-config: ERROR: 169.254.95.120/16 has host bits set

[Björn Tillenius]

Got an error running 30-maas-01-bmc-config on a machine that had Redfish data in dmidecode:

File "/tmp/user_data.sh.10mqad/scripts/commissioning/29-maas-01-bmc-config", line 1014, in detected
    self._detect()
  File "/tmp/user_data.sh.10mqad/scripts/commissioning/29-maas-01-bmc-config", line 1000, in _detect
    self._configure_network(iface, data)
  File "/tmp/user_data.sh.10mqad/scripts/commissioning/29-maas-01-bmc-config", line 971, in _configure_network
    ipv4 = ipaddress.IPv4Network((ipv4_addr, ipv4_mask)).with_prefixlen
  File "/usr/lib/python3.8/ipaddress.py", line 1459, in __init__
    raise ValueError('%s has host bits set' % self)
INFO: Loading IPMI kernel modules...
INFO: Checking for HP Moonshot...
INFO: Checking for Redfish...
ERROR: 169.254.95.120/16 has host bits set

29-maas-01-bmc-config is a copy of 30-maas-01-bmc-config but changed to print a traceback.

Note also that this shows that using ValueError for expected errors might not be a good idea. It would be good to change it to a more specific errors, so that we only catch the ones that we expect.