2.6.2 new nodes always are calculated as ephemeral deploys

[Freddy]

The process we use to add new machines is to create a new machine by POST to the /machines endpoint, and then commission the machine.

After upgrading to 2.6.2 all commissions would fail to complete silently. the cloud-init.final service would fail on the netplan configuration

/etc/netplan/50-maas.yaml:2:3: Error in network definition: unknown key 'config'

After investigation, this `50-maas.yaml` file should only be present if it is an ephemeral deploy. The commission is NOT an ephemeral deploy, and the ephemeral_deploy column in the database was false. However, since it was a new node created by POST to /machines, it had no disks so the `ephemeral_deploy` property returned true because is_diskless was true.

https://git.launchpad.net/maas/tree/src/maasserver/models/node.py?h=2.6#n1357

We were able to resolve this by removing the check for `is_diskless` in line 1357 linked above. I don't know how you want to proceed in resolving this issue because I do not use the ephemeral deploy feature. However, this completely prevented us from adding nodes to our environment and I believe should be a priority to fix. Others are encountering it as well and posting on discord.

https://discourse.maas.io/t/issue-with-commissioning/1301

[Freddy (fwieffering)]

It looks like this may be fixed in 2.7. Is it possible to get a fix published for 2.6?

[Alberto Donato (ack)]

I think https://bugs.launchpad.net/maas/+bug/1851622 is the relevant fix (in 2.7)