Re: [libvirt] [PATCH] qemu: configurable VNC port boundaries for domains

On Tue, May 22, 2012 at 09:09:55AM -0600, Eric Blake wrote: > On 05/22/2012 09:00 AM, Dave Allan wrote: > > On Tue, May 22, 2012 at 04:10:03PM +0200, Martin Kletzander wrote: > >> The defines QEMU_VNC_PORT_MIN and QEMU_VNC_PORT_MAX were used to find > >> free port when starting domains. As this was hardcoded to the same > >> ports as default VNC servers, there were races with these other > >> programs. This patch includes the possibility to change the default > >> starting port as well as the maximum port in qemu config file. > > > > Hi Martin, > > > > Two design comments: > > > > 1) https://bugzilla.redhat.com/show_bug.cgi?id=782814 requests that > > the default port be changed to avoid conflicts, which seems reasonable > > to me. > > If we choose better defaults for new installations, we still need to > worry about preserving existing ranges when upgrading old installations. > This may need some coordination with the spec file doing some %post > magic to add in vnc_port_min with a value other than 5900 to qemu.conf > on new installations, but leaving it unspecified when doing an upgrade. That's a good point, we certainly don't want to break things on upgrade. At least one case that would is where people have opened the old range in a firewall, and now instead of ports, say, 5900-n, now people will be getting some other range. > > 2) I agree with the config option since most applications on the > > system will want the system defaults. However, IMO in this case an > > application writer should be given the option in the XML to override > > the system default. > > Agreed - I think we need both solutions - qemu.conf to specify the > default range, and per-domain XML to specify an override (does the XML > need to specify a range, or just a single port?). I think a range, like the config option.