This allows the user to configure systemd tmpfiles.d via
`environment.etc."tmpfiles.d/X.conf".text = "..."`, which after #93073
causes permission denied (with new X.conf):
```
ln: failed to create symbolic link '/nix/store/...-etc/etc/tmpfiles.d/X.conf': Permission denied
builder for '/nix/store/...-etc.drv' failed with exit code 1
```
or collision between environment.etc and systemd-default-tmpfiles
packages (with existing X.conf, such as tmp.conf):
```
duplicate entry tmpfiles.d/tmp.conf -> /nix/store/...-etc-tmp.conf
mismatched duplicate entry /nix/store/...-systemd-246/example/tmpfiles.d/tmp.conf <-> /nix/store/...-etc-tmp.conf
builder for '/nix/store/...-etc.drv' failed with exit code 1
```
Fixes#96755
declare -a is not sufficient to make the array variable actually
exist, which resulted in the script failing when the target object did
not have any DT_NEEDED entries. This in turn resulted in some
initramfs libraries not having their rpaths patched to point to
extra-utils, which in turn broke the extra-utils tests.
symlinkJoin can break (silently) when the passed paths contain symlinks
to directories. This should work now.
Down-side: when lib/tmpfiles.d doesn't exist for some passed package,
the error message is a little less explicit, because we never get
to the postBuild phase (and symlinkJoin doesn't provide a better way):
/nix/store/HASH-NAME/lib/tmpfiles.d: No such file or directory
Also, it seemed pointless to create symlinks for whole package trees
and using only a part of the result (usually very small part).
These are now only installed by systemd if HAVE_SYSV_COMPAT is true,
which only is the case if you set sysvinit-path and sysvrcnd-path (which
we explicitly unset in the systemd derivation for quite some time)
From the systemd release notes:
nss-mymachines lost support for resolution of users and groups, and now
only does resolution of hostnames. This functionality is now provided by
nss-systemd. Thus, the 'mymachines' entry should be removed from the
'passwd:' and 'group:' lines in /etc/nsswitch.conf (and 'systemd' added
if it is not already there).
Since systemd 246, these are only installed by systemd if
HAVE_SYSV_COMPAT is true, which only is the case if you set
sysvinit-path and sysvrcnd-path (which we explicitly unset in the
systemd derivation for quite some time)
There's a circular dependency to systemd via cryptsetup and lvm2
(systemd -> cryptsetup -> lvm2 -> udev=systemd).
However, cryptsetup only really needs the devmapper component shipped
with lvm2. So build `pkgs.cryptsetup` with a lvm2 that doesn't come with
udev.
- Give a more accurate description of how fileSystems.<name/>.neededForBoot
works
- Give a more detailed description of how fileSystems.<name/>.encrypted.keyFile
works
The toplevel derivations of systems that have `networking.hostName`
set to `""` (because they want their hostname to be set by DHCP) used
to be all named
`nixos-system-unnamed-${config.system.nixos.label}`.
This makes them hard to distinguish.
A similar problem existed in NixOS tests where `vmName` is used in the
`testScript` to refer to the VM. It defaulted to the
`networking.hostName` which when set to `""` won't allow you to refer
to the machine from the `testScript`.
This commit makes the `system.name` configurable. It still defaults to:
```
if config.networking.hostName == ""
then "unnamed"
else config.networking.hostName;
```
but in case `networking.hostName` needs to be to `""` the
`system.name` can be set to a distinguishable name.
This lets users do sneaky things before systemd starts, and
permanently affect the environment in which systemd runs. For example,
we could start systemd in a non-default network namespace by setting
the systemdExecutable to a wrapper script containing:
#!/bin/sh
ip netns add virtual
touch /var/run/netns/physical
mount -o bind /proc/self/ns/net /var/run/netns/physical
exec ip netns exec virtual systemd
_note: the above example does literally work, but there are unresolved
problems with udev and dhcp._
