NIC information (networks / PXE interface) get's lost due to re-discovering NIC's during commissioning

[Andres Rodriguez]

First, I enlisted and commissioned the machine, and the result was the following:

MAC IP Network
52:54:00:96:d6:2b (PXE) 192.168.122.100 (dynamic) maas-virbr0 (192.168.122.0/24)
52:54:00:c1:56:d0 maas-virbr0 (192.168.122.0/24)

Second, I deleted the 52:54:00:c1:56:d0 NIC, and re-commissioned. MAAS successfully updated its NIC information. However, the mapping with network and the discovery of PXE interface was lost. (My guess is because we update all NIC interfaces instead of just removing the one missing). The result was the following:

MAC IP Network
52:54:00:96:d6:2b

Third, I re-added the 52:54:00:c1:56:d0 NIC, and re-commissioned. MAAS successfully update its NIC information. The mapping with network was done successfully after the update but the detection of the PXE was lost (when the machine first PXE booted, before updating NIC info, it detected that 52:54:00:96:d6:2b was the PXE interface, but this disappeared after the NIC's where updated. My guess is that this is due to the fact that all NIC's on the machine were updated, instead of adding the missing one).

MAC IP Network
52:54:00:96:d6:2b 192.168.122.100 (dynamic) maas-virbr0 (192.168.122.0/24)
52:54:00:c1:56:d0 192.168.122.101 (dynamic) maas-virbr0 (192.168.122.0/24)

Fourth, I re-commissioned again without deleting any NIC to see if it would successfully detect the PXE interface this time. However, the result is the same. The PXE interface detection gets lost, and my guess is because during commissioning, NIC's get updated regardless of whether we added new ones or not.

MAC IP Network
52:54:00:96:d6:2b 192.168.122.100 (dynamic) maas-virbr0 (192.168.122.0/24)
52:54:00:c1:56:d0 192.168.122.101 (dynamic) maas-virbr0 (192.168.122.0/24)

What needs to happen during commissioning, to not lose information such as network mapping or PXE interface discovery, is that we should only be adding / deleting the NIC that's been added or removed for the machine respectively. If there has been no NIC changes, then this information should not be updated at all.

[Andres Rodriguez (andreserl)]

This is really critical, as it is causing MAAS to provide the static IP address to the wrong NIC.

[Andres Rodriguez (andreserl)]

Ok, so it seems that in every commissioning, new NIC's are being added, instead of only adding/removing the missing ones. This is also when there are no new nics nor deleted ones, it still seems old get removed and new get added:

Before commissioning:
In [14]: [(mac, mac.id) for mac in node.macaddress_set.all()]
Out[14]: [(<MACAddress: 52:54:00:c1:56:d0>, 17), (<MACAddress: 52:54:00:96:d6:2b>, 18)]

After commissioning:
In [15]: [(mac, mac.id) for mac in node.macaddress_set.all()]
Out[15]: [(<MACAddress: 52:54:00:c1:56:d0>, 19), (<MACAddress: 52:54:00:96:d6:2b>, 20)]

The index has changed.

[Andres Rodriguez (andreserl)]

We've disable MAC re-discovery in the meantime:

https://code.launchpad.net/~rvb/maas/disable-mac-recommission/+merge/255196