Boxbuild Tweaks

Note

Abstract

This document describes a few ways to modify box build VMs for testing/debugging.

Increase Box Build Image Size

In particularly large builds, you may find that the upstream build boxes aren’t quite large enough, and fail to build during the final few steps. While it is a bit of a kludge, it is possible to increase the size of the build box.

To do so, follow these steps:

Note

For this example, we will assume the box increase question is an Ubuntu box, located in ~/.kiwi_boxes/ubuntu

  1. While the VM is offline, locate the VM you want to modify and resize with qemu-img. Here we will increase the size by 20G. The VM will have to be told to utilize this space in the following steps.

$ qemu-img resize Ubuntu-Box.x86_64-1.22.04-System-BuildBox.qcow2 +20G

  1. When relaunching your kiwi-ng box build, make sure you use --no-snapshot and --box-debug options within your build command/script. Example:

$ kiwi --debug --profile="Disk" --type oem system boxbuild --no-snapshot \
--box-memory=32G --box-smp-cpus=16 --box-debug --box ubuntu -- \
--description ./ubuntu-jammy --target-dir /build/kiwi/outputs/

  1. When the build fails and drops you into the VM console, you will need to extend the partition of the VM rootfs, then resize with resize2fs. In this example, parted was used and the partition in question was /dev/vda3.

$ parted
# Can run parted print to check for relevant partitions if needed.
(parted) $ print
(parted) $ resizepart 3 100%
# Exit from parted
(parted) $ quit
# Run resize2fs to grow the filesystem to fill the space
$ resize2fs /dev/vda3

  1. From this point, depending on where your build failed, it may be possible to continue your build from inside the box, using the existing 9p mount points defined by your build command. Using the command above as an example, /result within the box maps up to /build/kiwi/outputs on the host, and it’s possible to run

$ kiwi-ng --profile="Disk" --type oem  system create \
--root=/result/build/image-root/ --target-dir=/result

  1. If the rebuild from within was successful, you can copy the files from /result to /bundle, from within the VM, where /bundle maps to your target-dir on the host.