Re: [Qemu-devel] [PATCH v2 5/5] block/rbd: add support for 'mon_host', 'auth_supported' via QAPI

[Jeff Cody <jcody@redhat.com>]

On Tue, Feb 28, 2017 at 10:28:49AM +0000, Daniel P. Berrange wrote:
> On Tue, Feb 28, 2017 at 10:16:51AM +0000, Daniel P. Berrange wrote:
> > On Mon, Feb 27, 2017 at 10:57:44PM -0500, Jeff Cody wrote:
> > > On Mon, Feb 27, 2017 at 04:47:54PM -0600, Eric Blake wrote:
> > > > On 02/27/2017 12:58 PM, Jeff Cody wrote:
> > > > > @@ -604,6 +620,29 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict *options, int flags,
> > > > >          goto failed_shutdown;
> > > > >      }
> > > > >  
> > > > > +    /* if mon_host was specified */
> > > > > +    if (host) {
> > > > > +        const char *hostname = host;
> > > > > +        char *mon_host = NULL;
> > > > > +
> > > > > +        if (port) {
> > > > > +            mon_host = g_strdup_printf("%s:%s", host, port);
> > > > 
> > > > Does Ceph care about IPv6 (in which case you may need [host]:port when
> > > > host itself includes ':')?
> > > >
> > > 
> > > Some quick sanity testing seems to show that it does not need [] for ipv6
> > > addresses, which is nice.
> > 
> > Hmm, that is very odd to me, as that means parsing is ambiguous. The
> > ceph 'mon_host' option allows the port to be omitted, so given a
> > string  2001:242:24:23   there's no way of knowing whether it is
> > a IPv6 addr 2001:242:24:23, with no port, or an addr 2001:242:24 with
> > port of 23
> 
> Looking at the source code to ceph it appears that if you omit the
> use of [], then it will treat the entire string as being the address
> without port. It does look to support use of [], so we should use
> that IIUC.

For the sake of clarity, when you say we should use [] for ipv6, you mean
QEMU (rather than doing it in libvirt)?
> 
> https://blog.widodh.nl/2014/11/ceph-with-a-cluster-and-public-network-on-ipv6/
> 
> See also entity_addr_t::parse in $CEPH/src/msg/msg_types.cc which is
> what I think parses the mon addr. NB, I've not tested this yet, so
> if you have a live ceph cluster with ipv6, it'd be good to verify that
> using [] is correct.
>

Do you think this needs to be in place before either A) we pull the series
for softfreeze, or B) 2.10?  I.e., is this something we can fix up later?
It is OK if not, but I have a flight leaving soon and can't work on the
series anymore -- so depending on this and how v3 review goes, we may just
need to slip the series to 2.10.