feat(xo-server): add MBR to cloud-init drive

[fbeauchamp]

Description

terraform need the cloud init trive to be bootable under windows. Added a MBR
disk size is limited to 32MB, is it enough ?

Checklist

• Commit
  • Title follows commit conventions
  • Reference the relevant issue (Fixes #007, See xoa-support#42, See https://...)
  • If bug fix, add Introduced by
• Changelog
  • If visible by XOA users, add changelog entry
  • Update "Packages to release" in CHANGELOG.unreleased.md
• PR
  • If UI changes, add screenshots
  • If not finished or not tested, open as Draft

[fbeauchamp]

dumped the buffer + mbr in a file , fdisk -l=>

Disque /tmp/partition : 10 MiB, 10486272 octets, 20481 secteurs
Unités : secteur de 1 × 512 = 512 octets
Taille de secteur (logique / physique) : 512 octets / 512 octets
taille d'E/S (minimale / optimale) : 512 octets / 512 octets
Type d'étiquette de disque : dos
Identifiant de disque : 0x00000000

Périphérique    Amorçage Début   Fin Secteurs Taille Id Type
/tmp/partition1 *            1 20481    20481    10M  e W95 FAT16 (LBA)

[julien-f]

We are waiting for some user testing before merging this PR.

@fbeauchamp Just let me know when it's good for you 🙂

[olivierlambert]

I did a test here, it doesn't break our Debian Cloud init template, and I can see the partition layout, and mount it manually. So LGTM. No idea for the Windows cloudinit thing.

[julien-f]

@olivierlambert I think we should wait for Windows testing (at least a few days), if it does not work this PR is useless.

[julien-f]

Shall we merge this now?

[fbeauchamp]

Shall we merge this now?

still no news from our tester , I think we should merge it