Re: [libvirt] [virt-tools-list] [PATCH virt-manager v4] Add inspection to virt-manager

On Tue, Jul 19, 2011 at 10:17:02AM -0400, Cole Robinson wrote: > On 07/19/2011 03:49 AM, Richard W.M. Jones wrote: > > On Mon, Jul 18, 2011 at 05:41:00PM -0400, Cole Robinson wrote: > >> On 07/18/2011 02:53 PM, Richard W.M. Jones wrote: > >>> This updates 1/4 with the fixes you suggested. Also, all check-pylint > >>> warnings and errors have been fixed. > >>> > >>> Rich. > >>> > >> > >> Thanks! Pushed the series. > > > > In reply to your comment on IRC: > > > > crobinso> rjones: so in the default usage of virt-manager in fedora, > > the guest inspection probably won't work since we > > save disk images in /var/lib/libvirt/images/, which > > regular user doesn't have access to. > > crobinso> rjones: that's not entirely clear from feature page. > > crobinso> rjones: I'm thinking of adding a disk path access check in > > the inspection thread, to avoid flooding the logs > > with errors if we can't even read the disk > > image. that should be safe to do? > > > > I always run virt-manager as root (or from sudo) so this hasn't been > > an issue. What user does virt-manager run as normally? > > > > I think most common usage is just running virt-manager as the logged in > user, using policykit to authenticate the libvirt connection so the rest > of the app doesn't have root privs. > > > AFAICT if there's no access to the disks, then the call to either > > g.add_drive_opts or g.launch will throw an exception. But the > > inspection._vmseen hash will mean this will only happen once per > > domain per run of virt-manager. > > > > On an unrelated note: I think we need to cache inspection between runs > > of virt-manager. Does virt-manager currently store permanent state (I > > assume it must do - ie. list of connections), and where? > > > > We store config like that in gconf, though I don't think sticking > largish data like list of applications or a png in there is a good idea. > hostname + os info could be cached, though ideally the latter would be > stored in libvirt XML at some point. Agreed, it would be desirable to cache the PNGs in $HOME/.virt-manager though, perhaps as $HOME/.virt-manager/icons/$CONN_URI/$DOMAIN_UUID To avoid growing without bound, probably want to have virt-manager purge files in that directory on startup, if the PNG is older than 3 months and the associated connection or domain no longer exists. ie don't immediately purge them, since a user might later re-add a connection or re-create a VM. Another thought though is that we've also got some work going on a little plugin for gnome-shell to capture & display screenshots of VMs. It might be nice for virt-manager to take advantage of this too, while also the shell plugin might like the icon image. So perhaps we should declare a standard location for storing assets related to a VM, which are expensive to extract/fetch. $HOME/.local/libvirt/$CONN_URI/$DOMAIN_UUID/screenshot.png $HOME/.local/libvirt/$CONN_URI/$DOMAIN_UUID/icon.png $HOME/.local/libvirt/$CONN_URI/$DOMAIN_UUID/osinfo.json or something like that