[NFS-Ganesha-Devel] Re: should we make nfs-ganesha an optional part of a ceph build?

(I sent this to a smaller list of folks yesterday, but I think it probably warrants wider discussion). Recently Varsha added the necessary infrastructure to bring up nfs-ganesha via vstart.sh. The current implementation requires that ganesha already be installed on the box (usually via distro packaging), but that poses a bit of a problem. A distro ganesha package will have likely been built vs. a completely different version of libcephfs and librados. Even if you build right off of ceph master branch, you won't get the benefit of any recent client bugfixes when you want to test ganesha. You'd have to build new ganesha packages, install them, etc. I think we ought to consider making a nfs-ganesha build an optional part of a ceph build (maybe enable it with cmake -DNFS_GANESHA=ON or something). It doesn't take very long to build it (typically only a minute or two on my box), and we could disable the parts that ceph doesn't care about (other FSALs primarily). We could also have vstart just error out when you run it with NFS=X on a build that didn't have ganesha enabled. OTOH, the potential downside here is that it'll likely add other build- time dependencies, and would require some extra cmake or scripting wizardry. Nothing insurmountable, but it might represent a maintenance burden going forward, particularly for something that's basically only going to be used for vstart. I'm also not sure how we'd do this in practice. I don't think you can do optional submodules, so we might have to look at other methods of pulling in the ganesha tree, or just live with it as a submodule that only gets used when ganesha is enabled.