Using fai-mirror and fai-cd for an offline Xenial installer

[Alexander Thomas]

Hello,

I am trying to create a bootable USB stick that can install a basic
Ubuntu Xenial system with certain customisations, without needing
internet access for the installation. I am running the FAI setup from
within a Xenial host. From what I find in previous messages, the
approach for making a Ubuntu installer is to make a Jessie NFSROOT
with a Xenial basefile.

The workflow should be:
1. Make or download a Xenial basefile
2. fai-make-nfsroot
3. fai-mirror
4. fai-cd

As a first test, I took the ‘simple’ example config and went through
this workflow (skipping step 1), which seemed to work although I
didn't check the output for any errors, and I'm not sure what I ended
up with. It is possible to install a VM from that ISO with the Xenial
menu option, but the installed system looks weird. Logging into X gets
stuck on an empty and non-functional background image, and consoles
show the Debian logo and say “Ubuntu Xenial Xerus (development
branch)” instead of “Ubuntu 16.04.1 LTS”. Looks like a Frankenstein
install between Debian and Ubuntu.

I had my doubts from the start about making a fai-mirror with an
nfsroot from a different distribution than the one from the mirror
itself, but theoretically it seems possible. I tried to make it work
by first stripping all the unneeded parts from the config and only
keeping the bits needed for the nfsroot and Ubuntu. However,
fai-mirror keeps on failing because it seems to try to download jessie
packages from ubuntu APT sources, or vice versa.

Is it a sane idea anyway to try to make a stand-alone FAI CD that
installs Xenial from a jessie nfsroot? If it is possible, how can it
be done? If not, is there another way?

Regards,
Alexander