[3.1] Setting interface into unconfigured does not reset auto-assign IP mode

[Alan Baghumian]

There are occasions where certain network interfaces should be set as "Unconfigured" to be configured later on during deployments by external tools such as juju and similar.

There is currently an issue with MAAS 3.1 Snap (3.1.0-10901-g.f1f8f1505) where setting an interface into "Unconfigured" mode does not remove "auto-assign" IP mode.

Steps to reproduce:

1) Via MAAS WebUI, go to a Machine > Network > Choose an interface that has IP mode set to "Auto-Assign" (put one in this mode if there are none), then click "Edit Physical" under actions menu.

2) Set Subnet to "Unconfigured" and save.

3) On the next screen, the IP mode remains in "Auto assign" while subnet shows as "Undonfigured".

I also tried setting the Subnet, while putting IP mode in "Unconfigured", saving then going back and setting Subnet to "Unconfigured", but IP mode reverts back to "Auto-Assign" from "Unconfigured".

Ultimately setting "Subnet" to "Unconfigured" should also reset the IP mode to "Unconfigured". In other words "Auto-Assign" IP from an "Unconfigured" subnet is meaningless.

There is another related issue, there is no way to reset "Auto-Assign" IP mode back to "Unconfigured" unless you actually delete the interface using MAAS WebUI and Re-Add it.

I tested this on four different machines and was able to reproduce it every single time.

Please let me know if you need more information and I'll provide.

Thank you.