Re: multistrap support

[Claudius Heine <claudius.heine.ext@siemens.com>]

Hi Kazu,

I don't speak for the whole Isar community, but just from my point of 
view. For context I implemented the switch from multistrap to debootstrap.

On 13/02/2019 14.14, kazuhiro3.hayashi@toshiba.co.jp wrote:
> Hi,
> 
> I would like to know if isar still has some plans to use multistrap again
> (or similar existing tools if exists) to generate target images.

No, only debootstrap is supported and we will most probably stick with that.

> Multistrap for isar-image-base has been removed by the following commit:
> https://github.com/ilbers/isar/commit/19a314559178f7afd93ce3dafe8c8647ca6c8884
> and replaced by setup_root_file_system() in isar-bootstrap-helper.bbclass,
> which seems to use (pre-built?) isar-bootstrap-$ROOTFS_DISTRO-$ROOTFS_ARCH
> as the base tree instead of running the debootstrap process.
> 
> I guess that the main purposes of quitting multistrap is that
> there is no big update for a few years (though the last update is 2.2.10 on Nov. 2018)
> Are there any other reasons?

That is one of them. Debootstrap is better supported by the main Debian 
community than any other bootstrapping tools. And since it is out of 
scope or the Isar Project to implement its own bootstrapping mechanism, 
we will stick with the second most official one 'debootstrap'. The 
Debian installer being the most official way to install Debian, which is 
a bit to bulky and integrated to be easily used in a scripted environment.

Both multistrap and debootstrap had or still have some inconveniences 
with our usage and it would of course be great to have one that fits 
exactly our purposes and is used and supported by the broader 
Debian/Embedded Debian and possible Debian server community. But as I 
said Isar does not have the resources to implement that.

> (Some bugs difficult to be fixed, mismatches with isar specification, etc.)
> 
> The current isar-bootstrap based approach would work fine for isar system,
> but in that case, it might be difficult to share efforts for
> developing and maintaining the functionality with non isar users.
> I'm just interested in the future plan of isar.

Maybe you can give an example about which feature you think could be 
moved outside of the isar project and be used separately.

One issue here is that Isar uses bitbake as the build task scheduler, so 
shell scripts etc. are difficult to extract from it to be used outside 
of Isar. And if they are extracted from the Isar recipes, then using 
them in Isar again is disadvantageous for the Isar build process.

So sharing code between a bitbake/isar project and other build systems 
is not really possible.

regards,
Claudius

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