Comment # 22 on bug 1173402 from Thomas Blume

(In reply to Fabian Vogt from comment #21)
> (In reply to Thomas Blume from comment #20)
> > I've created testpackages with a proposed patch at:
> > 
> >  https://build.opensuse.org/package/show/home:tsaupe:branches:openSUSE:
> > Factory:dracut-bsc1173402/dracut
> > 
> > It worked well in my test setup, but it would be good if you could confirm.
> 
> Confirmed to work with:
> rd.neednet -> DHCPv4
> rd.neednet ip=dhcp6 -> DHCPv6
> rd.neednet bootdev=eth0 -> DHCPv4 (once)
> 
> > Here is the commit for reference:
> > 
> > https://github.com/tblume/dracut/commit/
> > 2127271afdbf8ab669a86b382e75eb51a9965396
> 
> I'd actually go a step further:
> https://github.com/Vogtinator/dracut-1/commit/
> b39e4fe4d53a0806f82aa303690a7a7da9d09711
> 
> That also makes other differences (bugs?) more obvious:
> - in the bootdev case, it calls load_ipv6, then do_dhcp. AFAICT do_dhcp is
> equivalent to do_dhcp -4 for wicked, but probably not dhclient?
> - for s in $(getargs nameserver); do ... done is only done if ip is not set,
> but not in the ip=dhcp/dhcp6 case or the bootdev case
> - load_ipv6 is missing before do_dhcp -6

Thanks a lot Fabian, I took the freedom to merge your commit and addressed the
above issues.
Looking into the dhclient manpage I've found that it defaults to dhcp4, so it
should behave just like wicked.

There was one little quirks in your patch, it didn't address the case when
net.bootdev exists.
In that case do_dhcp (-4) would have been already called in the BOOTDEV branch.
So, I've added a check.

My updated patch is at:

https://github.com/tblume/dracut/commit/824f0308428d3e270a346ad69f38f70387304111

Would be nice if you could take another look and double check.