Re: [Libguestfs] Can't access remote URI

On 12/20/2012 05:53 PM, Richard W.M. Jones wrote: > On Thu, Dec 20, 2012 at 05:30:03PM +0800, Wanlong Gao wrote: >> On 12/20/2012 05:08 PM, Richard W.M. Jones wrote: >>> On Thu, Dec 20, 2012 at 04:00:10PM +0800, Wanlong Gao wrote: >>>> Hi Rich, >>>> >>>> We just found that the libguestfs can't access the remote URI. >>>> When doing guestfs__add_drive_opts(), we always add files from >>>> local system, it's related the -c|--connect option. >>>> >>>> As I know, we are using local kernel to lunch the min-guest, >>>> and it's hard to attach remote disks to our local min-guest. >>>> >>>> Our test team found this problem by using following command, >>>> >>>> # virt-sysprep -c qemu+ssh://<host>/system -d domname >>>> >>>> Then, for example the path of remote disk is /work/rhel.img, >>>> but we are about to access the /work/rhel.img locally. >>>> >>>> So, IMHO, if we are about to not support the remote URI, we >>>> should give a error message first. But access local disks >>>> instead of remote disks are definitely wrong here. >>>> >>>> Maybe we also need document this. >>>> >>>> Any thoughts? >>> >>> John Eckersberg is working on implementing this for libguestfs 1.22. >>> Most of the libvirt support has been done already, but there is some >>> more libvirt and libguestfs work. >>> >>> As for reporting an error, it's difficult because libvirt doesn't give >>> a simple way to find out if a URI is "remote" or not (whatever >>> "remote" means). And even if libvirt did, it's not necessarily true >>> that remote URIs wouldn't work, eg. if the user attached a LUN to both >>> the remote and local machine. >> >> So, at this time, we should report a useful message to user but not just >> fail without any thing. Right? > > I don't know how you can report a useful message, since it's not > obvious if a libvirt URI is remote. eg. How about the URI > "qemu+ssh://foo/session" where the hostname of the local machine is > "foo.example.com"? Or the hostname is "bar.example.com" but the local > DNS contains a PTR record "foo" -> "bar"? Oops, I don't have a good idea either. So, as John is doing this work, can you share the working progress and the roadmap so that we can help doing something?