Enable mgr modules to report their "runnability"
If a module has a dependency which is missing, we should be able to learn that on a mgr (even in standby), so that it can include that in its beacon to mons, and the mons can say "no, you can't enable that module" if we already know the module can't work.
So maybe modules get a "is_loadable" method that does a try/except import of dependencies, and reports back.
This would depend on the change to load modules on standbys (https://github.com/ceph/ceph/pull/16651)
#2 Updated by John Spray about 5 years ago
Right, although now that I think about it, we could probably also catch ImportErrors from when we try to load the module from the C++ side (although in general I prefer modules don't do that, so that they can run selftest methods even without dependencies).