Implementation is now compatible with the option's .type already defined.
This allows us to pass `config.users.users.<user>.hashedPassword` even if this is null (the default).
Before:
true => access
false => no access
hash => access via password
null => eval error
After:
true => access
false => no access
hash => access via password
null => no access
This adds support for declaring tmpfiles rules exclusively for the
systemd initrd. Configuration is possible through the new option
`boot.initrd.systemd.tmpfiles.settings` that shares the same interface as
`systemd.tmpfiles.settings`.
I did intentionally not replicate the `rules` interface here, given that
the settings attribute set is more versatile than the list of strings
used for `rules`. This should also make it unnecessary to implement the
workaround from 1a68e21d47 again.
A self-contained `tmpfiles.d` directory is generated from the new initrd
settings and it is added to the initrd as a content path at
`/etc/tmpfiles.d`.
The stage-1 `systemd-tmpfiles-setup.service` is now altered to no longer
operate under the `/sysroot` prefix, because the `/sysroot` hierarchy
cannot be expected to be available when the default upstream service is
started.
To handle files under `/sysroot` a slightly altered version of the
upstream default service is introduced. This new unit
`systemd-tmpfiles-setup-sysroot.service` operates only under the
`/sysroot` prefix and it is ordered between `initrd-fs.target` and the
nixos activation.
Config related to tmpfiles was moved from initrd.nix to tmpfiles.nix.
In #327506, we stopped using `/sbin` in the `pathsToLink` of `initrdBinEnv`. This inadvertantly stopped including the `sbin` directory of the `initrdBin` packages, which meant that things like `mdadm`'s udev rules, which referred to binaries by their `sbin` paths, stopped working.
The purpose of #327506 was to fix the fact that `mount` was not calling mount helpers like `mount.ext4` unless they happened to be in `/sbin`. But this raised some questions for me, because I thought we set `managerEnvironment.PATH` to help util-linux find helpers for both `mount` and `fsck`. So I decided to look at how this works in stage 2 to figure it out, and it's a little cursed.
---
What I already knew is that we have [this](696a4e3758/nixos/modules/system/boot/systemd.nix (L624-L625))
```
# util-linux is needed for the main fsck utility wrapping the fs-specific ones
PATH = lib.makeBinPath (config.system.fsPackages ++ [cfg.package.util-linux]);
```
And I thought this was how `mount` finds the mount helpers. But if that were true, then `mount` should be finding helpers in stage 1 because of [this](696a4e3758/nixos/modules/system/boot/systemd/initrd.nix (L411))
```
managerEnvironment.PATH = "/bin";
```
Turns out, `mount` _actually_ finds helpers with [this configure flag](696a4e3758/pkgs/os-specific/linux/util-linux/default.nix (L59))
```
"--enable-fs-paths-default=/run/wrappers/bin:/run/current-system/sw/bin:/sbin"
```
Ok... so then why do we need the PATH? Because `fsck` has [this](a75c7a102e/disk-utils/fsck.c (L1659))
```
fsck_path = xstrdup(path && *path ? path : FSCK_DEFAULT_PATH);
```
(`path` is `getenv("PATH")`)
So, tl;dr, `mount` and `fsck` have completely unrelated search paths for their helper programs
For `mount`, we have to use a configure flag to point to `/run/current-system`, and for `fsck` we can just set PATH
---
So, for systemd stage 1, we *do* want to include packages' `sbin` paths, because of the `mdadm` problem. But for `mount`, we need helpers to be on the search path, and right now that means putting it somewhere in `/run/wrappers/bin:/run/current-system/sw/bin:/sbin`.
With the the Systemd-based initrd, systemd-journald is doing the logging.
One of Journald's Trusted Journal Fields is `_HOSTNAME` (systemd.journal-fields(7)).
Without explicitly setting the hostname via this file or the kernel cmdline, `localhost` is used and captured in the journal.
As a result, a boot's log references multiple hostnames.
With centralized log collection this breaks filtering (more so when logs from multiple Systemd-based initrds are streaming in simultaneously.
Fixes#318907.
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).
This allows us to set things like dependencies in a way that we can
catch typos at eval time.
So instead of
```nix
systemd.services.foo.wants = [ "bar.service" ];
```
we can write
```nix
systemd.services.foo.wants = [ config.systemd.services.bar.name ];
```
which will throw an error if no such service has been defined.
Not all cases can be done like this (eg template services), but in a lot
of cases this will allow to avoid typos.
There is a matching option on the unit option
(`systemd.units."foo.service".name`) as well.
these changes were generated with nixq 0.0.2, by running
nixq ">> lib.mdDoc[remove] Argument[keep]" --batchmode nixos/**.nix
nixq ">> mdDoc[remove] Argument[keep]" --batchmode nixos/**.nix
nixq ">> Inherit >> mdDoc[remove]" --batchmode nixos/**.nix
two mentions of the mdDoc function remain in nixos/, both of which
are inside of comments.
Since lib.mdDoc is already defined as just id, this commit is a no-op as
far as Nix (and the built manual) is concerned.
The maximum length for a GPT label supported by systemd is 36
characters. When a repart definition contains a label that is longer
than the supported maximum length, it is ignored by systemd-repart and
a log message is produced.
The new assertion makes this obvious to the user at evaluation time,
allowing them to either drop the property entirely or choose a supported
label within the length limit instead.
Before there was a kernel modules path named kernel-modules which then got turned
into linux-X.X.XX-modules-shrunk. Now the unshrunk package is called linux-X.X.XX-modules
and gets turned into X.X.XX-modules-shrunk.
These should be defaults as they're pretty reasonable to want to
override as a user. Unsure how to change the slice defaults to be
overridable, that should probably be a later conversation.
