What were you trying to do that didn't work?

When building an OCI image while specifying a /boot partition in the blueprint, the /boot partition gets configured as Partition 4 instead of partition 3:

# parted /dev/nbd0 print
Model: Unknown (unknown)
Disk /dev/nbd0: 5586MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: 

Number  Start   End     Size    File system  Name  Flags
 1      1049kB  2097kB  1049kB                     bios_grub
 2      2097kB  212MB   210MB   fat16              boot, esp
 4      212MB   2359MB  2147MB  xfs                bls_boot
 3      2359MB  5586MB  3226MB                     lvm

This leads to Cloud providers to enlarge /boot instead of /, and breaks osbuild design (OSBuild - General principles) webpage:

The partition that contains the root filesystem, whether this is a plain formatted partition, an LVM Volume Group, or a Btrfs partition, is always last in the partition table layout when it is automatically added. For Disk customizations the user-defined order is respected.

What is the impact of this issue to you?

Can't generate an image with /boot partition.

Please provide the package NVR for which the bug is seen:

python3-osbuild-158-1.el10.noarch
osbuild-selinux-158-1.el10.noarch
osbuild-158-1.el10.noarch
osbuild-depsolve-dnf-158-1.el10.noarch
osbuild-composer-core-149-4.el10_1.x86_64
osbuild-luks2-158-1.el10.noarch
osbuild-lvm2-158-1.el10.noarch
osbuild-ostree-158-1.el10.noarch
osbuild-composer-worker-149-4.el10_1.x86_64
osbuild-composer-149-4.el10_1.x86_64

How reproducible is this bug?

Always

Steps to reproduce

1. Create a basic blueprint with /boot customization

   name = "TEST_MINIMAL_10_WITH_BOOT"
   description = "RHEL10"
   distro = "rhel-10.1"
   
   [[customizations.filesystem]]
   mountpoint = "/boot"
   size = "2048MiB"
   

2. Push the blueprint and generate an OCI image

   # composer-cli blueprints push test_minimal_10_with_boot.toml 
   # composer-cli compose start TEST_MINIMAL_10_WITH_BOOT oci
   # composer-cli compose image <ID>
   

3. Check the partitioning

   # modprobe nbd
   # qemu-nbd -c /dev/nbd0 ./<ID>.qcow2
   # fdisk -l /dev/nbd0
   

Expected results

Proper ordering (root as partition 4):

Device        Start      End Sectors  Size Type
/dev/nbd0p1    2048     4095    2048    1M BIOS boot
/dev/nbd0p2    4096   413695  409600  200M EFI System
/dev/nbd0p3  413696  4607999 4194304    2G Linux extended boot
/dev/nbd0p4 4608000 10909662 6301663    3G Linux LVM

Actual results

Wrong ordering:

Device        Start      End Sectors  Size Type
/dev/nbd0p1    2048     4095    2048    1M BIOS boot
/dev/nbd0p2    4096   413695  409600  200M EFI System
/dev/nbd0p3 4608000 10909662 6301663    3G Linux LVM
/dev/nbd0p4  413696  4607999 4194304    2G Linux extended boot

Partition table entries are not in disk order.