[PATCH 0/3] rootfs-postcommands: replace the sysusers.d postcommand

[Louis Rannou <lrannou@baylibre.com>]

This is a suggestion to replace the management of sysusers.d in the build.

sysusers.d is a set of configuration files to declare system users and groups
supposed to be created at boot when they do not exist.

Until now, we have a rootfs post command that checks those configuration and
creates missing users and groups. This command is defective when a home
directory or a shell is specified. The actual parsing leads to incorrect
commands such as:

`useradd --shell /sbin/nologin --uid 0 --comment "Super User" /root --system
root`

Also, it appears there is more interest for a command that checks all required
users are correctly created before the rootfs is done.

Therefore, the first patch here replaces the command `systemd_create_users` by a
command `systemd_sysusers_check` that every users/groups declared in sysusers.d
configuration files already exist in `/etc/passwd` and `/etc/group` and check at
best if the properties match.

This reveals two misconfiguration:

WARNING: memfault-image-1.0-r0 do_rootfs: User root has been defined as (root, 0, 0, root, /home/root, /bin/sh) but sysusers.d expects it as (root, 0, -, Super User, /root, -)
WARNING: memfault-image-1.0-r0 do_rootfs: Group wheel has never been defined

1. As systemd supposes the rootfs should not be configurable, whereas it is possibl
ein yocto through the variable ROOT_HOME,, a second patch suggests to replace
the sysusers.d configuration file 'basic.conf' by ours.

2. The user wheel can be used for some superuser tasks such as consulting the
systemd journal or manage printers in cups. It can also be used for su and sudo
in replacement of the sudo group. It looks good to add this in the base-passwd
files. It is not upstreamable as the debian point of view is that the wheel
group is unset by default.

Signed-off-by: Louis Rannou <lrannou@baylibre.com>
---
Louis Rannou (3):
      rootfs-postcommands: change sysusers.d command
      systemd: replace the sysusers.d basic configuration
      base-passwd: add the wheel group

 meta/classes-recipe/rootfs-postcommands.bbclass    | 133 +++++++++++++++++----
 .../base-passwd/0007-Add-wheel-group.patch         |  20 ++++
 meta/recipes-core/base-passwd/base-passwd_3.6.1.bb |   1 +
 meta/recipes-core/systemd/systemd/basic.conf.in    |  40 +++++++
 meta/recipes-core/systemd/systemd_253.3.bb         |   5 +
 5 files changed, 175 insertions(+), 24 deletions(-)
---
base-commit: 8078a62739f08e60de98e194b9cd987d8c5b2e7b
change-id: 20230613-sysusersd-614778830079

Best regards,
-- 
Louis Rannou <lrannou@baylibre.com>