Regardless of mutable or immutable users, systemd-sysupdate never
updates existing user records and thus will for example never change
passwords for you.
It only support initial passwords and now actively asserts agains other
paswords.
On Linux we cannot feasbibly generate users statically because we need
to take care to not change or re-use UIDs over the lifetime of a machine
(i.e. over multiple generations). This means we need the context of the
running machine.
Thus, stop creating users statically and instead generate them at
runtime irrespective of mutableUsers.
When /etc is immutable, the password files (e.g. /etc/passwd etc.) are
created in a separate directory (/var/lib/nixos/etc). /etc will be
pre-populated with symlinks to this separate directory.
Immutable users are now implemented by bind-mounting the password files
read-only onto themselves and only briefly re-mounting them writable to
re-execute sysusers. The biggest limitation of this design is that you
now need to manually unmount this bind mount to change passwords because
sysusers cannot change passwords for you. This shouldn't be too much of
an issue because system users should only rarely need to change their
passwords.
systemd-sysusers cannot create normal users (i.e. with a UID > 1000).
Thus we stop trying an explitily only use systemd-sysusers when there
are no normal users on the system (e.g. appliances).
The activation script that remounts the /etc overlay now handles other
mount points on top of /etc by bind mounting them to the new temporary
/etc overlay and then atomically revealing it.
Fix regular expression used to get bootloader versions from bootctl status.
This avoids problems that occur in minor environments like mine.
References: #296563
we have a zoo of ways to call subprocesses.
Let's just replace this with one function that has reasonable defaults.
i.e. I catched instances where commands where run in a shell.
When `services.resolved` is enabled, then `resolve [!UNAVAIL=return]`
is added to `system.nssDatabases.hosts` with priority 501,
which prevents lower-priority NSS modules from running
unless systemd-resolved is not available.
Quoting from `man nss-resolve`:
> To activate the NSS module, add "resolve [!UNAVAIL=return]" to the line
> starting with "hosts:" in /etc/nsswitch.conf. Specifically, it is
> recommended to place "resolve" early in /etc/nsswitch.conf's "hosts:"
> line. It should be before the "files" entry, since systemd-resolved
> supports /etc/hosts internally, but with caching. To the contrary, it
> should be after "mymachines", to give hostnames given to local VMs and
> containers precedence over names received over DNS. Finally, we
> recommend placing "dns" somewhere after "resolve", to fall back to
> nss-dns if systemd-resolved.service is not available.
Note that the man page (just) recommends "early" and means with this
"before the 'files' and 'dns' entries". It does not insist on being
first or excluding other modules.
For this reason, libvirt NSS modules should run before the `resolve`
module. They should come right next to `mymachines` because both are
conceptually very similar -- they resolve local VMs/containers.
Since the data source of the libvirt NSS modules are local
plain text files (see source code of the libvirt NSS module),
no performance impact is expected form this raise of priorities.
Other NSS modules in NixOS also explicitly set their priority, which is
why this change increases consistency.
Fixes#322022
Any future behavioral modifications to switch-to-configuration should
also be made to switch-to-configuration-ng. Leave a note at the top of
the script to ensure people don't forget.
These messages should be able to be printed in all cases. In particular, trying to coerce a `null` to a string is an error unless passed through `toString`.
