Adding drivers to initrd using kickstart & dracut

[Richard W.M. Jones]

I have a working kickstart for building a Fedora 20 guest.  But I want
to add Xen drivers to the guest's initrd.

So far I'm doing:

%post
pushd /etc/dracut.conf.d
echo 'add_drivers+="xen-blkfront xen-netfront"' > xen-drivers.conf
popd
dracut
%end

However although this creates the /etc/dracut.conf.d/xen-drivers.conf
file in the guest, it doesn't add the Xen drivers to the initramfs.
(I also tried running dracut --add-drivers ... but that does nothing).

Any ideas what I'm doing wrong?

Rich.