hierarchical comps groups proposal

[Jens Petersen]

Hi,

> 2014-03-05 9:40 GMT+01:00 Jens Petersen < petersen at redhat.com > :
> > I would like to suggest the idea of adding support for
> > hierarchical comps groups to Fedora.

> (I'm not going to contribute actual work on this anyway, but) do we actually
> need that complexity?

I am not sure how complex it is. As Ales pointed out
it might allow us to remove environment groups for example
so it might actually simplify comps, as well as eliminating some repetitions.
Note that more modular comps would also be helpful for people
writing kickstart files for example.

> > The idea is make yum groups in comps more modular,
> > ie groups could require other groups not just packages;
> > at this time I don't think it would require any GUI changes.

> So the proposal is not to show them as really hierarchical, and not to add
> any structurally new user-visible features[1] just to avoid repetition in
> the comps file?

To me current comps is quite messy because everything has to be "flat"
which limits its flexibility in various ways.
But right, *initially* I reckon hierarchical groups need not *require*
any GUI changes to anaconda, etc.  In the first instance it would be
about providing greater structure and more fine-grained groups in comps.
Later these could also be used for more advanced selection of groups
in the installer and package GUI.

> Would it be an option to use an XML entity for the duplicated parts, or a
> similar preprocessing step during generation of comps.xml, to create the
> current group format instead? That would have the advantage of not having to
> adjust yum/dnf/anaconda to support the new feature.

Perhaps, but the primary goal/motivation is not just to eliminate
the duplication of common package sets but to provide a richer, more modular,
flexible hierarchy of comps groups. Perhaps an explicit example would help.

Jens