MAAS should not allow editing network interfaces of deployed machines

[Bui Hong Ha]

Currently, MaaS does not allow network interfaces' configurations (for example: changing fabrics, changing subnet) to be modified after a machine was deployed. When a user try to modify the fabric in MaaS UI by Machine > Network > Actions > Edit Physical, MaaS UI allows users the form to be submitted but does not output any validation error.

It would be helpful if MaaS UI can display validation error when a user tries to change interfaces after machine deployment.

[Thorsten Merten (thorsten-merten)]

Were able to reproduce it. We could also think about disabling the edit physical button for deployed machines instead of showing an error afterwards.

[Christian Grabowski (cgrabowski)]

Confirmed on the backend as well, it seems the DeployedInterfaceForm inherits from MAASModelForm rather than InterfaceForm, which has a generic save and has no logic preventing edits, even more so than the regular InterfaceForm child classes.