tree e568a2087ba4f8335a1e2ba10a8e01e9809b4de8
parent e0db72ca567b5142bb6a31d745b3bf78cd8eb53a
author Jan Schär <jan@monogon.tech> 1750674727 +0000
committer Jan Schär <jan@monogon.tech> 1750865872 +0000

m/test/launch: build image at runtime

Test launch now builds the node disk image from the OCI image, instead
of creating a qcow2 snapshot of the pre-built disk image. This speeds up
tests and test cluster launch.

The OCI image is uncompressed and payloads are not verified, which
enables the previously implemented copy_file_range optimization. If the
host file system supports reflinks, this has a similar effect as the
qcow2 snapshot had previously: Building the image is very fast as the
rootfs data is not copied on disk. On my machine, it takes 30 ms.

The build before launching a cluster is now faster: The MkImage step
taking 6 s is replaced by MkOCI taking 1 s. The majority of this time is
spent by Bazel computing hashes of files. For MkImage, the generated
file was a 5 GB disk image consisting mostly of zeroes, which took a
long time to hash.

Additionally, the qcow2 layer added some overhead, which is now gone.
The HA e2e test previously took 103 s on my machine, now it takes 80 s.

Change-Id: I0ce5059626cc682061c26ac3c8d11b752e641c60
Reviewed-on: https://review.monogon.dev/c/monogon/+/4294
Tested-by: Jenkins CI
Reviewed-by: Tim Windelschmidt <tim@monogon.tech>