On Tue, Jul 31, 2018 at 05:48:50PM +0300, Nir Soffer wrote: > Thanks everyone for the good input on > http://lists.nongnu.org/archive/html/qemu-block/2018-07/msg00168.html > > I'm convinced that the best direction for oVirt is having NBD client instead > of using the kernel nbd client. I think a C library would be best, but a > python > version is faster to implement and may be good enough for oVirt, so I'm > starting in this direction.
I think clients in all languages are welcome, though I agree that eventually we're going to need a C client (and not the Curl track which I was headed down, which was the wrong direction). > If you like to check the prototype, see: > https://gerrit.ovirt.org/c/93384/ > > qemu's nbd/client.c was very helpful so far, since NBD doc > https://github.com/NetworkBlockDevice/nbd/blob/master/doc/proto.md > is not very clear. I agree the protocol spec has evolved by accretion so that it no longer has a coherent narrative. Anyway some general comments on your client in no particular order: - Be nice if it was a separate Python library. - It should support TCP sockets too. In fact those are probably more important than Unix sockets in the bigger picture. Is there not a Python "socket client" class you can subclass from which does all the socket machinery? - It looks as if you're only handling fixed new-style. Good! Don't bother implementing anything else. I would test against ‘qemu-nbd -x’ primarily, then secondarily against nbd-server and nbdkit. Once it interoperates with all 3 then you're good to go :-) > Not sure that imageio is the best place for this. Do you have a better idea > about a better home for this library? A separate Python library in PyPi or wherever would be my preference. I don't know what the policy is in imageio about dependencies though. [...] Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com libguestfs lets you edit virtual machines. Supports shell scripting, bindings from many languages. http://libguestfs.org
