debian-forge-composer/internal/weldr
Ondřej Budai 973639d372 distro/rhel84: use a random uuid for XFS partition
Imagine this situation: You have a RHEL system booted from an image produced
by osbuild-composer. On this system, you want to use osbuild-composer to
create another image of RHEL.

However, there's currently something funny with partitions:

All RHEL images built by osbuild-composer contain a root xfs partition. The
interesting bit is that they all share the same xfs partition UUID. This might
sound like a good thing for reproducibility but it has a quirk.

The issue appears when osbuild runs the qemu assembler: it needs to mount all
partitions of the future image to copy the OS tree into it.

Imagine that osbuild-composer is running on a system booted from an imaged
produced by osbuild-composer. This means that its root xfs partition has this
uuid:

efe8afea-c0a8-45dc-8e6e-499279f6fa5d

When osbuild-composer builds an image on this system, it runs osbuild that
runs the qemu assembler at some point. As I said previously, it will mount
all partitions of the future image. That means that it will also try to
mount the root xfs partition with this uuid:

efe8afea-c0a8-45dc-8e6e-499279f6fa5d

Do you remember this one? Yeah, it's the same one as before. However, the xfs
kernel driver doesn't like that. It contains a global table[1] of all xfs
partitions that forbids to mount 2 xfs partitions with the same uuid.

I mean... uuids are meant to be unique, right?

This commit changes the way we build RHEL 8.4 images: Each one now has a
unique uuid. It's now literally a unique universally unique identifier. haha

[1]: a349e4c659/fs/xfs/xfs_mount.c (L51)
2020-12-15 16:43:39 +01:00
..
api.go distro/rhel84: use a random uuid for XFS partition 2020-12-15 16:43:39 +01:00
api_test.go distro/rhel84: use a random uuid for XFS partition 2020-12-15 16:43:39 +01:00
compose.go weldr: rename C{Waiting,Running,Finished,Failed} 2020-11-09 14:17:19 +01:00
json.go weldr: implement cancel route 2020-06-12 10:00:50 +02:00
upload.go weldr: rename C{Waiting,Running,Finished,Failed} 2020-11-09 14:17:19 +01:00
util.go composer/job-queue: add scaffolding for the job queue API 2019-09-26 19:53:06 +02:00