[libvirt-users] libvirtd vs XDG_RUNTIME_DIR

[Daniel P. Berrange]

On Wed, Mar 09, 2016 at 01:01:40PM -0500, Lars Kellogg-Stedman wrote:
> I ran into an odd problem today.  I wanted to share it here in the
> hopes of maybe saving someone else some lost time.
> 
> When you run libvirtd as an unprivileged user (e.g., if you target
> qemu:///session from a non-root account), then libvirt will open a
> unix domain socket in one of two places:
> 
> - If XDG_RUNTIME_DIR is defined, then inside
>   $XDG_RUNTIME_DIR/libvirt/libvirt-sock
> 
> - If XDG_RUNTIME_DIR is *not* defined, then inside
>   $HOME/.cache/libvirt/libvirt-sock
> 
> With a CentOS 7 system, at least, if you ssh directly into an
> account, XDG_RUNTIME_DIR is set.  But!  If you `su -` to the account
> from root, e.g:
> 
>     # su - stack
> 
> Then XDG_RUNTIME_DIR is *not* set.  The problem is a little subtle,
> because most operations you will perform will work just fine in both
> cases: you can query for defined but not active guests, storagep
> pools, volumes, and so forth without a problem and you'll get the same
> answer.

IMHO this is a bug in the pam config. We really expect to see the
same environment setup no matter how you login  text console vs su
vs ssh vs GDM.  If that's not happening, its always going to cause
bad behaviour across many apps, not only libvirt.


Regards,
Daniel
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