Fedora 22/23 template

[marmarek]

Checklist:

• add support for dnf to builder-fedora plugin
• setup dnf to use updates proxy in TemplateVM
• setup PackageKit to use updates proxy in TemplateVM (#982)
• make sure that dom0 updates can be downloaded by f22-based VM
• make sure that yum hooks are still called (sync appmenus, "updates installed" notify)
• adjust default application shortcuts (if needed)
• build the template, verify services (qrexec, gui, etc), disable unneeded services
• test upgrade path

[marmarek]

Status update:
Generally fc22 introduced new package manager - dnf instead of yum
(actually it was available also in fc21, but not as default). This makes
a lot of problems with the template building/updating code. Some work is
already done - for example there is fc22 branch in my builder-fedora
repo. But some more is needed - for example convincing all that stuff to
use our updates proxy.

[marmarek]

Status update:
Generally fc22 introduced new package manager - dnf instead of yum
(actually it was available also in fc21, but not as default). This makes
a lot of problems with the template building/updating code. Some work is
already done - for example there is fc22 branch in my builder-fedora
repo. But some more is needed - for example convincing all that stuff to
use our updates proxy.

[marmarek]

Not a strict blocker, but pretty severe issue: DNF takes a lot of CPU power for processing repository metadata. Upstream bug (incorrectly closed as a duplicate...): https://bugzilla.redhat.com/show_bug.cgi?id=1227014

The impact is that, the mere checking for updates (which is run in every VM every 6 hours) takes about 10-15 minutes at 100% CPU. At least for the first time (after VM startup), but probably every time after repository metadata got updated.

[marmarek]

Not a strict blocker, but pretty severe issue: DNF takes a lot of CPU power for processing repository metadata. Upstream bug (incorrectly closed as a duplicate...): https://bugzilla.redhat.com/show_bug.cgi?id=1227014

The impact is that, the mere checking for updates (which is run in every VM every 6 hours) takes about 10-15 minutes at 100% CPU. At least for the first time (after VM startup), but probably every time after repository metadata got updated.