[Libosinfo] [libosinfo PATCH] os: Add kernel-url-argument API

[Fabiano Fidêncio]

On Fri, 2019-05-03 at 13:07 +0200, Fabiano Fidêncio wrote:
> On Thu, May 2, 2019 at 4:39 PM Fabiano Fidêncio <fidencio at redhat.com>
> wrote:
> > Tree based installations will require a kernel-url-argument to be
> > assed. Let's provide an API to the apps to get this info from
> > OsinfoOS.
> > 
> > https://gitlab.com/libosinfo/osinfo-db/issues/28
> > 
> > Signed-off-by: Fabiano Fidêncio <fidencio at redhat.com>
> 
> I've discusses this with Cole off-list and we've decided that going
> for an "inheritance" (pero no mucho) way would be better.
> I'll change the implementation for something towards the line of:
> current.kernel_url_argument = current.kernel_url_argument or
> derived_from.kernel_url_argument
> 
> With that we'll be able to keep kernel_url_argument as a single one
> and just replace it in case a new one is added (which will be needed
> for Fedora >= 19, for instance).
> 
> A v3 (of the whole thing) will be submitted.

Okay, I have this work done but before submit the v3, I'd like to raise
one possible issue and confirm that having this kind of duplication is
fine.

In the v2, I've been using as part of the scripts something like:
<xsl:value-if select="os/kernel-url-argument"/>

Once we start inheriting kernel-url-argument, the kind of call shown
above wouldn't be possible anymore, leading us to have, as part of the
scripts, something like (for RHEL):
<xsl:choose>
  <xsl:when test="os/version < 7">
    <xsl:text> method</xsl:text>
  </xsl:when>
  <xsl:otherwise>
    <xsl:text> inst.repo</xsl:text>
  </xsl:otherwise>
</xsl:choose>

This is duplication of info will be needed because not all the <os/>
entris will have the <kernel-url-argument/> attribute.

IMO it still looks better in this way (please, check v1[0]) than having
to have the entry added in all OSes.

Cole, what do you think?

If you're okay with this, I'll just submit the v3.

[0]: https://www.redhat.com/archives/libosinfo/2019-April/msg00188.html

Best Regards,
-- 
Fabiano Fidêncio