Shouldn't use rmadison

[Loïc Minier]

Hi

This is to collect my thoughts on dropping the need for rmadison which seems to be the reason for the devscripts Depends/Recommends.

Currently, vm-builder/VMBuilder/plugins/ubuntu/distro.py uses rmadison to query the version (particularly the ABI version) of the Xen kernel to use for the guest. This is used as a default for the --xen-kernel and --xen-ramdisk filenames in the generated config file. I understand that the expectation is that the host has the kernels for the guest system installed.

What's wrong with the current approach?
- devscripts is heavy and pulls in many deps not desirable on a server install (mostly useful on developers' systems)
- rmadison introduces a runtime dependency on the network and Launchpad / CGIs in particular; that is, if Launchpad is down, rmadison fails; rmadison fails multiple times per day against the Debian servers too (albeit vm-builder doesn't support Debian ATM); it might be desirable to run vm-builder in environments without access to the public Internet / Launchpad, or during Launchpad downtimes, and passsing --xen-kernel / --xen-ramdisk is slightly less handy
- this is not friendly to Ubuntu derivatives or other Debian derivatives not providing a rmadison service, or for local xen kernels, but these require porting anyway

*If* vm-builder really needs to query this data, I would recommend parsing the Packages.gz files of the target (perhaps from $target/var/lib/apt/*_Packages).

However, I believe it's useful to have the kernel package installed within the xen guest, to provide the corresponding modules. So I would propose that:
- vm-builder installs linux-image-xen (or linux-image-server, or linux-image-virtual etc.) in the xen guests
- vm-builder uses the $target/boot/ramdisk and $target/boot/kernel files (without the $target prefix) for the xen config, unless overriden on the command-line

Does the proposed approach makes sense?

Thanks,

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: ubuntu-vm-builder 0.12.3-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.32-19.28-generic 2.6.32.10+drm33.1
Uname: Linux 2.6.32-19-generic x86_64
Architecture: amd64
Date: Sun Apr 11 15:10:34 2010
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=fr_FR:fr:en_GB:en
 PATH=(custom, user)
 LANG=fr_FR.UTF-8
 SHELL=/bin/zsh
SourcePackage: vm-builder

[Chuck Short (zulcss)]

Yes this makes more sense to me at least.

Regards
chuck