[Libguestfs] [PATCH] Differentiate 'distro' and 'distrofamily' in Sys::Guestfs::Lib

[Daniel P. Berrange]

On Fri, Jul 17, 2009 at 12:41:04PM +0100, Matthew Booth wrote:
> On 17/07/09 12:21, Richard W.M. Jones wrote:
> >On Fri, Jul 17, 2009 at 12:06:31PM +0100, Matthew Booth wrote:
> >>On 17/07/09 11:21, Daniel P. Berrange wrote:
> >>>IMHO doing this is a big mistake. This is what we did for virt-install
> >>>and hugely regret it. Things just don't fall into a nice hierarchy. We
> >>>are now looking at doing a flat list of distros + tagging/categorization
> >>>relationships to be defined.
> >>>
> >>>   http://www.redhat.com/archives/et-mgmt-tools/2009-June/msg00018.html
> >>Thanks, Dan.
> >>
> >>What problems did you hit? I'm inclined to think I might get away with
> >>it for virt-v2v because we also have so much other additional info about
> >>the system. So far, 'redhat' pretty much means it uses rpm rather than
> >>anything else.
> >
> >How about instead of "distrofamily" we add flags to tell us what
> >we actually want to know:
> >
> >   uses_rpm
> >   uses_dpkg
> 
> or, as this would be single-os specific:
> 
> package_management=rpm
> package_management=dpkg

Yep, this looks good to me, though perhaps name it  'package_format', unless
you are actually wanting to represent the basic package tool vs format.

This packaging stuff is a great example of the  trouble of the distro 
family idea. eg, if you wanted to track the package type, then  you'd want 
fedora + rhel together, since they both use rpm.  If you wanted to track 
package repository service, then you'd want fedora & rhel separate  (aka,
YUM repo vs RHN). If you  wanted to track package mgmt command line tool,
then you'd want fedora + rhel5 separate from rhel <= 4, (aka '/usr/bin/yum'
vs '/usr/bin/up2date'). So even for the simple task of package mgmt, the 
'distrofamily' is insufficiently expressive 

> My only concern about that scheme is that at this point we have little 
> idea about what we need to know. I guess it won't be too hard to add it 
> as we go along.

I think this is a benefit ! You can trivially add new metadata tags for
specific things you discover you need to track, and not have to worry
about typing to squash them into an ill-fitting distro-family set.

Daniel
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