storage: NFS - no way to browse NFS servers

[andreasn]

In the usability testing of NFS, we identified that all three out of four participants wished to browse the available NFS servers.

[andreasn]

I have no idea if this is even possible.

[andreasn]

Quotes from the test:

• Provided you know the address, you should be fine.
• I didn't see any way to browse a domain or a domain. I had to know the exact server name, and it didn't discover that for me.
• I would like to see a directory to pick the server, and potentially to pick the mount path, it should show up in the storage logs.

[garrett]

It's possible to have NFS advertised on the local network using zeroconf/avahi:

• https://askubuntu.com/questions/19590/how-do-i-share-nfs-mounts-over-zeroconf#19834
• https://wiki.archlinux.org/index.php/Avahi#NFS

…but it requires a bit of set-up on server side.

[martinpitt]

I keep this open as enhancement, but in general there's no way to discover NFS shares. Sure you can wrap some Avahi announcement around that, but that would be just for cockpit - nothing else supports that. NFS comes from an era when admins still knew the IP addresses of their servers by heart, and discovery wasn't a thing..

[mvollmer]

Note that Cockpit does discovery of exported paths once you have typed in the server address, by running showmount -e. However, the default firewall rules block whatever showmount needs so usually people see nothing.

[garrett]

Apparently Kodi does NFS browsing... https://forum.kodi.tv/showthread.php?tid=321545

However, a quick glance over the code Kodi uses (from libnfs) and I think it's probing the entire local network?

• https://github.com/sahlberg/libnfs/blob/master/include/nfsc/libnfs.h#L1913
• https://github.com/sahlberg/libnfs/blob/3ba2a2c1fdbc27dad477fa91d70b6999ee7335af/lib/libnfs-sync.c#L1866

So I guess it scans the local network, and then does the equivalent of showmount -e on the NFS servers it finds?