Discouraging use of virInterface* APIs

Laine's attempt long ago [1] to deprecate/obsolete the virInterface* APIs did not receive a standing ovation. However he raised many good points which are still valid today. If anything, netcf, the libvirt netcf backend, and the whole interface driver have become more stale. Personally, I wish we could deprecate and eventually obsolete the APIs and nuke the entire driver, but understand that's not desirable/realistic upstream. Given the state of the thing, I'd like to hear opinions on adding some words to the interface API page and virtinterfaced man page that describe the state of the APIs/driver and discourages their use. The motivation for this request comes from my efforts to take advantage of libvirt's modularization and not provide virtinterfaced (libvirt-daemon-driver-interface package) for certain use-cases. Having upstream documentation warning of the limitations and inactive development of the APIs/driver would help in convincing unsuspected users to find a better solution. And I think the use of "unsuspected" is correct :-). Projects closer to libvirt, like virt-manager, ditched use of the APIs long ago. But projects with less cross-pollination may not be aware of the general uselessness. As an example, we recently discovered cockpit-machines uses virConnectListAllInterfaces and virInterfaceGetXMLDesc. It's not clear to me why cockpit gathers this info. AFAICT it's not used for anything. The code was added long ago [2] with no info on purpose or what it's supposed to achieve. We've opened a github issue [3] to discuss removing use of these APIs. Pointing cockpit-machines developers to upstream libvirt documentation that describes the state of virInterface* and sets realistic expectation might help in convincing them to follow virt-managers footsteps and drop use of the APIs. I can provide the words of discouragement in the form of a patch if folks are receptive to the idea :-). Regards, Jim [1] https://listman.redhat.com/archives/libvir-list/2020-December/212791.html [2] https://github.com/cockpit-project/cockpit/pull/12465 [3] https://github.com/cockpit-project/cockpit-machines/issues/1777