images created are not unlinkable and cause uvtool to fail next sync

[Christian Ehrhardt ]

Hi,
this has puzzled me for a while and I think I now at least have enough data to report it for discussion.

It seems that when I sync images they get created without the right permissions/ownership?
Effectively I see after a sync of images that they look fine in a query:

uvt-simplestreams-libvirt query
release=xenial arch=amd64 label=daily (20160914)
release=yakkety arch=amd64 label=daily (20160914)

Those are the images of yesterday (this will become important)

And in the FS those look like
ll /var/lib/uvtool/libvirt/images/x-uvt-b64-Y29tLnVidW50dS5jbG91ZC5kYWlseTpzZXJ2ZXI6MTYuMDQ6YW1kNjQgMjAxNjA5MDk=
-rw------- 1 libvirt-qemu kvm 1020067840 Sep 14 09:22 /var/lib/uvtool/libvirt/images/x-uvt-b64-Y29tLnVidW50dS5jbG91ZC5kYWlseTpzZXJ2ZXI6MTYuMDQ6YW1kNjQgMjAxNjA5MDk=

All fine and working.
But on a subsequent sync that wants to unlink those uvt is failing, the same happens for a purge.
uvt-simplestreams-libvirt purge
Traceback (most recent call last):
  File "/usr/bin/uvt-simplestreams-libvirt", line 27, in <module>
    uvtool.libvirt.simplestreams.main()
  File "/usr/lib/python2.7/dist-packages/uvtool/libvirt/simplestreams.py", line 326, in main
    args.func(args)
  File "/usr/lib/python2.7/dist-packages/uvtool/libvirt/simplestreams.py", line 286, in main_purge
    purge_pool()
  File "/usr/lib/python2.7/dist-packages/uvtool/libvirt/simplestreams.py", line 142, in purge_pool
    volume.delete(0)
  File "/usr/lib/python2.7/dist-packages/libvirt.py", line 3359, in delete
    if ret == -1: raise libvirtError ('virStorageVolDelete() failed', vol=self)
libvirt.libvirtError: cannot unlink file '/var/lib/uvtool/libvirt/images/x-uvt-b64-Y29tLnVidW50dS5jbG91ZC5kYWlseTpzZXJ2ZXI6MTYuMDQ6YW1kNjQgMjAxNjA5MDk=': Permission denied

I wonder if something in my setup is odd - e.g. that the permissions shouldn't be this way to begin. And I wanted to discuss that before we debug deeper into what is happening in the code while executing.

[Robie Basak (racb)]

Thanks Christian. I've seen this too, as has Ryan I think, but we never found a clean reproducer on a fresh system. Is this the same as bug 1608704?

[Christian Ehrhardt  (paelzer)]

> Is this the same as bug 1608704?
>

The permissions described in 1608704 are true on my system as well.
Yet I can destroy guests just nice.
So I think not the same but maybe two symptoms of the same root cause.

[Robie Basak (racb)]

Also there's bug 1571068. Is this a dupe of that one?

[Christian Ehrhardt  (paelzer)]

Yes that is the one I mentioned on IRC.
And I helped this today to pass proposed, at least for me the issue is fixed by that.
So I'd dup this bug to 1571068