DNF and mock

[Miroslav Suchý]

I just spoke with two members of DNF team about default usage of DNF in mock. I would like to share outcomes of this
meeting.

First I would like to state that you can already optionally use DNF in your mock by setting:
  config_opts['package_manager'] = 'dnf'
in your
  /etc/mock/site-defaults.cfg
It is present in mock for half a year and all known problems have been resolved for some time.
You can even set this option per chroot target. E.g. put this line only in
  /etc/mock/fedora-rawhide-x86_64.cfg
and then only rawhide-x86_64 builds will use dnf while everything else will use yum.

DNF should be default packager manager in Fedora 22, so I started thinking how it affects mock.

I have a notion, that after branching of Fedora 22 I will change
  /etc/mock/fedora-rawhide-*.cfg
to use DNF by default. I.e. everything build for Fedora 23 would use DNF for building.

At the outset I thought that we use yum for older targets (epel-7, fedora-22..) indefinitely. Or to be precise until
those targets will be EOLed. But that would imply that yum have to be present in Fedora until Fedora 40 [1].
This is very unlikely to happen. More realistic expectation is that yum will disappear around Fedora 27 [2].
Which means that in  Fedora 27 you either will be unable to build packages for epel-7 or you will have to use DNF.
This is quite distant future and we will try our best to make this transition as much flawless as possible.
I just want to make you aware in advance. Of course if you want to help, you are very welcome.

I expect that we will be building Fedora 22- always by yum due to short Fedora life cycle. Yum will be still present in
Fedora 24 for sure.

[1] https://access.redhat.com/support/policy/updates/errata#Life_Cycle_Dates
[2] It’s Difficult to Make Predictions, Especially About the Future

-- 
Miroslav Suchy, RHCE, RHCDS
Red Hat, Senior Software Engineer, #brno, #devexp, #fedora-buildsys