installer integration

[Colin Watson]

On Sun, Jan 22, 2006 at 12:22:43AM -0500, Phillip Susi wrote:
> I figured the easiest way to do this is to add it as a dep to partman,
> only when I got the source to partman, it's control file does not show
> that it has a -udeb target, so now I'm confused. 

Not all udebs have names ending in "-udeb"; that suffix is generally
only there when it's necessary to avoid confusion with normal packages.
If you're looking at the partman source package, that's a red herring,
as it's an aggregate package I put together to simplify the process of
building the live CD-based installer.

The "partman" actually used in the installer is composed of lots of
pieces; 'apt-get source partman' in Dapper will get you most of them as
it happens (look in the source/ directory). However, the actual source
package you're asking about is probably partman-base.

> Why does partman appear to not have a -udeb, and what is the correct way 
> to integrate dmraid into the installer?

My inclination would in fact be not to touch partman at all, at least
not for running this utility that configures device-mapper. Instead, I'd
just put /sbin/dmraid in a dmraid-udeb without any postinst scripts or
anything like that (add a stanza for dmraid-udeb to debian/control with
XC-Package-Type: udeb and install the binary to
debian/dmraid-udeb/sbin/dmraid, built in a second pass with -Os and
without klibc or libselinux), and have disk-detect (from the hw-detect
source package) run it when looking for disks. That way, the check in
disk-detect for whether you have any partitionable media won't fire
mistakenly on dmraid-requiring systems. I'm happy to help you with this.

By the way, to answer another question I saw in #ubuntu-devel
scrollback, no, the installer doesn't use initramfs-tools or
mkinitramfs. It has its own build system, which can be found in the
debian-installer source package. disk-detect isn't in the installer
initrd, though, so I don't expect that you'll need to modify the
installer initrd anyway.

Also, the easiest way to test installer changes is often just to edit
the running installer on the fly. For example, in this case you could
create your dmraid-udeb and put it somewhere network-accessible; then,
after the installer has brought the network up, wget the package,
install it with 'udpkg -i', and 'nano /bin/disk-detect' to make that
script do whatever you need. Voilà, instant testing without having to
mess about with creating and burning CD images.

You generally seem to be asking installer questions on IRC when all the
people who know the installer best (including me) are fast asleep. I'm
happy to answer questions on this list or in private mail, and I suspect
timezones are such that you'll get better results that way.

Cheers,

-- 
Colin Watson                                       [cjwatson at ubuntu.com]