[Buildroot] SSHD issue between 2015 and 2020 versions

[Peter Seiderer <ps.report@gmx.net>]

Hello Stephen,

On Tue, 11 Aug 2020 10:02:16 -0400, Stephen Beckwith via buildroot <buildroot@busybox.net> wrote:

> Peter,
>   Thank you for your reply.  As I pointed out in the document:
> 2020 Buildroot creates a "full_users_table.txt" in the
> output/build/buildroot_fs directory, whereas the 2015 version puts a
> _users_table.txt in the output/build directory.  In the case of the 2015
> Buildroot, this file is "empty", whereas the 2020 Buildroot has an entry in
> this file that seems to be placed there by the Buildroot infrastructure.
> Why?  (I realize infrastructure changes occur between releases and we're
> making a might big leap here).
> I did update the Buildroot configuration via menuconfig (we save off a
> defconfig) since there are new default options for packages,etc in the new
> Buildroot release.
> A "simple build" is not possible, due to the nature of our setup using an
> external tree for the proprietary code.
> I did a build from "scratch" (we call extraclean, removes the output
> directory and does a complete re-setup of the target information we use).
> This builds fine, without opensshd enabled in the configuration.  I then
> use menuconfig to enable opensshd (in target packages->networking) and do a
> "make" here and I get this error at the end when we package up the entire
> system.  the opensshd itself builds correctly.
> The contents of the full_users_table.txt file comes from the
> sshd-sysusers.conf file in the 2020 Buildroot openssh package.  We do NOT
> use systemd or Device Tree.  Yet this is defined as the OPENSSH_USERS in
> the opensshd.mk file, how does this then get to the full_users_table.txt???

For a reference see [1] at 'LIBFOO_USERS'...

> I have enclosed the .config file used to build WITH opensshd enabled.

After a quick look at your config file (nothing suspicious) I would suspect
the content of the overlays/post-build-script (search for sshd there):

BR2_ROOTFS_OVERLAY="$(BR2_EXTERNAL_SP_DEV_PATH)/src/rootfs-overlay $(BR2_EXTERNAL_SP_DEV_PATH)/platform/mendo/rootfs-overlay"
BR2_ROOTFS_POST_BUILD_SCRIPT="$(BR2_EXTERNAL_SP_DEV_PATH)/scripts/post_rootfs_build.sh"

And/or the following change of mkusers ([2])...

Regards,
Peter

[1] https://buildroot.org/downloads/manual/manual.html#generic-package-reference
[2] https://git.buildroot.net/buildroot/commit/?id=497f7134fca4b111499b2fd23501d7e048303e7c

>
> I look forward to your reply.
>
> Regards,
> Stephen Beckwith
>
>
> On Mon, Aug 10, 2020 at 6:09 PM Peter Seiderer <ps.report@gmx.net> wrote:
>
> > Hello Stephen,
> >
> > On Mon, 10 Aug 2020 17:03:05 -0400, Stephen Beckwith <
> > embeddedsteve at gmail.com> wrote:
> >
> > > Please see the attached document that describes an issue that I've
> > > encountered when migrating from Buildroot 2015.08.1 to Buildroot 2020.02.
> > > At this point, I cannot include ssh/sshd for inclusion in the system,
> > which
> > > is necessary.
> >
> > Hard to determine what is causing your failure:
> >
> >         mkusers: user 'sshd' already exists with group 'users' (wants
> > 'sshd')
> >
> > Does it happen with an simple build? Or with your re-started one?
> >
> > Please provide a .config/defconfig file from your failing buildroot
> > configuration...
> >
> > Regards,
> > Peter
> >
> > >
> > > Any pointers/suggestions would be greatly appreciated.
> > >
> > > Regards,
> > > Stephen Beckwith
> >
> >