[Bug 2011535] Re: nova can't access instance image file because the file is now chowned to the kvm group by default

[Steve Langasek]

Hello Takashi, or anyone else affected,

Accepted nova into kinetic-proposed. The package will build now and be
available at https://launchpad.net/ubuntu/+source/nova/3:26.1.0-0ubuntu2
in a few hours, and then in the -proposed repository.

Please help us by testing this new package.  See
https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how
to enable and use -proposed.  Your feedback will aid us getting this
update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug,
mentioning the version of the package you tested, what testing has been
performed on the package and change the tag from verification-needed-
kinetic to verification-done-kinetic. If it does not fix the bug for
you, please add a comment stating that, and change the tag to
verification-failed-kinetic. In either case, without details of your
testing we will not be able to proceed.

Further information regarding the verification process can be found at
https://wiki.ubuntu.com/QATeam/PerformingSRUVerification .  Thank you in
advance for helping!

N.B. The updated package will be released to -updates after the bug(s)
fixed by this package have been verified and the package has been in
-proposed for a minimum of 7 days.

** Changed in: nova (Ubuntu Kinetic)
       Status: Triaged => Fix Committed

** Tags added: verification-needed verification-needed-kinetic

-- 
You received this bug notification because you are a member of Ubuntu
OpenStack, which is subscribed to nova in Ubuntu.
https://bugs.launchpad.net/bugs/2011535

Title:
  nova can't access instance image file because the file is now chowned
  to the kvm group by default

Status in nova package in Ubuntu:
  Fix Released
Status in nova source package in Kinetic:
  Fix Committed
Status in nova source package in Lunar:
  Fix Released

Bug description:
  [Impact]
  This affects the nova package for kinetic and lunar. It is a side-effect of the changes made in https://bugs.launchpad.net/charm-nova-compute/+bug/1967956, specifically (1) and (3) described in https://bugs.launchpad.net/charm-nova-compute/+bug/1967956/comments/10. We tightened the mode of directories under /var/lib/nova from 755 to 750, and the mode of files under /var/lib/nova from 644 to 640. As a result, adding nova to the kvm group was required for nova to be able to access vm disks. We did that for nova-compute-kvm package but failed to do so for the nova-compute-qemu package.

  == original bug description ==

  It seems libvirt package in Ubuntu 22.04 uses the kvm group instead of the libvirt-qemu group when launching a qemu process.
  Because of this change and the default behavior of libvirt which makes all image files chowned by the group/user to run qemu process, the instance files are owned by the kvm group, instead of the libvirt-qemu group.

  However currently the nova user is still added to the libvirt-qemu
  group instead of the kvm group.

  Because of this inconsistency nova can't access to instance image once
  the files are chowned to the kvm group.

  nova 3:26.1.0-0ubuntu1~cloud0
  libvirt 8.0.0-1ubuntu7.4

  I've found the problem in puppet jobs. (example https://zuul.opendev.org/t/openstack/build/d6f2fb2e92ad4ece86bcd3d8793bf920 )
  Example error in nova can be found here: https://2e4f6457af6d4bb29c73-cc818d493c2a52ef4d37701157d67702.ssl.cf2.rackcdn.com/877214/2/check/puppet-openstack-integration-7-scenario002-tempest-ubuntu-jammy/d6f2fb2/logs/nova/nova-compute.txt

  I've tested adding the nova user to the kvm group and confirmed this fixes the error.
  https://review.opendev.org/c/openstack/puppet-openstack-integration/+/877338

  [Test Case]
  At the most basic level we can install the nova-compute-qemu package on a machine, and install the nova-compute-kvm package on another machine, and compare the directory and file modes under the /var/lib/nova/ tree.

  I'm sure Takashi will be able to give feedback on the fix as well.

  [Regression Potential]
  This is fixing a regression. We already add the nova user to the kvm group as part of the nova-compute-kvm postinst script, and this fix is doing the same for the nova-compute-qemu postinst script. I don't foresee any new regressions as a result of this.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/nova/+bug/2011535/+subscriptions