I maintain a local mirror site for the Linux distributions we use. This is a simple rsync setup using ftpsync and Apache.

I recently added Ubuntu to the list, but ran into an issue when I tested an automated install. The installer complained it was “Unable to locate package puppet.”

In the preseed file, I tell the installer to also install this package with a pkgsel directive. (Later, using a late_command directive, the service is configured and started.)

d-i pkgsel/include string puppet

This worked great on Debian, but failed on the new Ubuntu mirror. It worked with the official mirror, though. After a bit of investigation, I discovered that the default Ubuntu install, unlike Debian, is configured for multiarch (at least on the releases I tested.)

debian:~$ lsb_release -a
Distributor ID: Debian
Description:    Debian GNU/Linux 10 (buster)
Release:        10
Codename:       buster
debian:~$ dpkg --print-foreign-architectures
debian:~$

ubuntu:~$ lsb_release -a
Distributor ID: Ubuntu
Description:    Ubuntu 18.04.5 LTS
Release:        18.04
Codename:       bionic
ubuntu:~$ dpkg --print-foreign-architectures
i386
ubuntu:~$

It was failing with the new mirror because I had limited the mirrored architectures to amd64, as I don’t have any 32-bit installs.

ARCH_INCLUDE="amd64 source"

Looking at my options to fix this, I could:

  1. remove the architecture with a dpkg --remove-architecture i386
  2. try to disable multiarch with a preseed command
  3. specify deb [arch=amd64] https://... in each of the apt sources to override the architectures apt uses
  4. add the i386 binaries to the mirror

I wanted others to be able to use this without any additional configuration so I chose the last option and just added i386 to the list in ftpsync-ubuntu.conf and manually ran the mirror script.

ARCH_INCLUDE="amd64 i386 source"

This added about 300GB to the local archive. Now, I have fully-automated PXE netboot installs for Ubuntu.