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.
Before this patch, if we:
1. add a new user in the config,
2. mount /home seperately,
3. not set neededForBoot for /home,
4. and run `nixos-rebuild boot`,
the newly added user's home will not be created after a reboot. This
is because when nixos/modules/config/update-users-groups.pl is running
in stage 2 to setup users, /home is not mounted.
This patch fixes this issue.
it's really easy to accidentally write the wrong systemd Exec* directive, ones
that works most of the time but fails when users include systemd metacharacters
in arguments that are interpolated into an Exec* directive. add a few functions
analogous to escapeShellArg{,s} and some documentation on how and when to use them.
With the previous change that enabled error propagation through
`inherit_errexit`, the script would fail if `errexit` was set, but
`inherit_errexit` was not. This is due to `shopt -p` exiting with an
error if the option is disabled. To work around this, use the exit
code instead of the text value returned by `shopt -p`.
Fixes#160869.
If an error occurs while trying to read a secret file, we want that
error to propagate to the main shell context. That means we have to
set the `inherit_errexit` option, which allows errors from subshells
to propagate to the outer shell. Also, the subshell cannot run as part
of another command, such as `export`, since that will simply ignore
the subshell exit status and only respect `export`s exit status; first
assigning the value to a variable and then exporting it solves issue.
/var/lib/nixos is used by update-users-groups.pl in the activation
script for storing uid/gid mappings. If this has its own mountpoint
(as is the case in some setups with fine-grained bind mounts pointing
into persistent storage), the mappings are written to /var/lib, /var,
or /. These may be backed by a tmpfs or (otherwise ephemeral storage),
resulting in the mappings not persisting between reboots.
- Give a more accurate description of how fileSystems.<name/>.neededForBoot
works
- Give a more detailed description of how fileSystems.<name/>.encrypted.keyFile
works
Introduce new functions which allows modules to define options where,
if the input is an attrset and the output is JSON, the user can define
arbitrary secrets.
