Bug#1011343: WISHLIST: Offical ALL-IN-ONE images?

Hey folks,

On Sat, May 21, 2022 at 04:59:27PM +0200, Thomas Schmitt wrote:
>Andrew M.A. Cater wrote to [email protected]:
>
>> I don't actually know how long it take to create the .jigdo and .template
>> files - I don't think it's as long as generating the full .iso files

Whether you make the .iso or not, we have to run the full process. The
*only* part of the process we can win on (a little) is by not actually
writing the .iso file to disk. If we don't want the .iso, we output to
/dev/null and save a little bit of output I/O [1]. All the same I/O us
used for input, of course - we have to scan all the data to generate
checksums, etc.

>They are created by libjte under control of libisofs under control of
>xorriso as side effect of actual ISO production under control of debian-cd.
>(I'm developer of libisofs and xorriso, and co-funder of libjte, which is
>now back in the hands of Steve McIntyre from whose genisoimage code it
>got large parts of its entrails.)
>
>I was possibly wrong with guessing that the ISO is dumped into /dev/null,
>although debian-cd seems to be smart enough to read the various checksums
>from the .jigdo files, rather than calculating them from the .iso files.
>The checksum code
>  https://sources.debian.org/src/debian-cd/3.1.35/tools/imagesums/#L57
>reminded me that there are .torrent files made, which obviously need
>the .iso files at least at build time.

No, youre initial guess is correct. We don't generate the .iso files
at all for the larger images [1]. This means we also don't have
torrent files for them [2]. There's no point generating the .torrent if
we don't have the full .iso available as well, after all.

[1] https://salsa.debian.org/images-team/debian-cd/-/blob/master/tools/make_image#L124
[2] https://cdimage.debian.org/cdimage/release/11.3.0/amd64/

>-------------------------------------------------------------------------
>
>> it's always good to have otehr people to think round a problem with.
>
>Is there documentation from which i could learn how the stuff in (i guess)
>/dists of DLBD-1 and DLBD-2 could be merged so that it properly describes
>a merged pool tree ?
>
>My rough idea would be:
>- mount both ISOs
>- derive merged /dists files
>- run xorriso to let it
>  - load DLBD-1 with its boot equipment
>  - merge-in the pool tree of mounted DLBD-2
>  - overwrite the old /dists files by the newly derived ones
>  - automatically replay the commands for the loaded boot equipment
>  - store the result as new .iso file
>
>The second step is where i would need info or advise.

The debian-cd code in tools/make_disc_trees.pl is not documentation
**as such**, but it's exactly how we create disc trees: all the
packages/sources and metadata of various flavours. It's baiscally just
making a self-contained apt repository on each medium.