[libvirt-users] provisioning with vagrant-libvirt leaves .img file only readable by root

[Hans-Christoph Steiner]

I'm using libvirt on Debian/stretch (testing) with vagrant and the
vagrant-libvirt plugin.  When I import a vagrant box (jessie64.box), the
resulting file permssions let anyone in the "kvm" group read the img.
But when I build upon that box, only root can read it:

-rw------- 1 root         root 20198785024 Sep 19 18:19
buildserver_default.img
-rwxr--r-- 1 libvirt-qemu kvm   2148663296 Sep  5 22:55
jessie64_vagrant_box_image_0.img

How can I control those file permissions as a regular user in the
libvirtd group?  I need to read that image in order to use qemu-img to
rebase and create a new vagrant box.  The current `vagrant package`
command only works with VirtualBox VMs, but its easy to make a .box if
you have read access to the libvirt QEMU .img file.

/etc/libvirt/storage/default.xml says:
  <target>
    <path>/var/lib/libvirt/images</path>
    <permissions>
      <mode>0755</mode>
    </permissions>
  </target>


You can find the context for this work here:
https://gitlab.com/fdroid/fdroidserver/issues/238

.hc

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