using freeform is the new standard way of using modules and should replace
extraConfig.
In particular, this will allow us to place a condition on mails
Before this patch, services.dendrite.environmentFile is used for
secrets and environment variable substitution only happens when this
option is used.
systemd-247 provides a mechanism called LoadCredential for secrets and
it is better than environment file. See the section of Environment=
in the manual of systemd.exec for more information.
This patch always substitute environment variables, which enables the
usage of systemd LoadCredential.
The Nix-provided `nix-daemon.socket` file has a
> ConditionPathIsReadWrite=/nix/var/nix/daemon-socket/socket
line, to skip that unit if /nix/var/nix/daemon-socket/socket is
read-only (which is the case in some nixos-containers with that folder
bind-ro-mounted from the host).
In these cases, the unit was skipped.
Systemd 250 (rightfully) started to also skip in these cases:
> [ 237.187747] systemd[1]: Nix Daemon Socket was skipped because of a failed condition check (ConditionPathIsReadWrite=/nix/var/nix/daemon-socket).
However, systemd < 250 didn't skip if /nix/var/nix/daemon-socket/socket
didn't /exist at all/, and we were relying on this bug in the case for
fresh NixOS systems, to have /nix/var/nix/daemon-socket/socket created
initially.
Move the creation of that folder to systemd-tmpfiles, by shipping an
appropriate file in `${nixPackage}/lib/tmpfiles.d/nix-daemon.conf`
(NixOS/nix#6285).
In the meantime, set a systemd tmpfiles rule manually in NixOS.
This has been tested to still work with read-only bind-mounted
/nix/var/nix/daemon-socket/socket in containers, it'll keep them
read-only ;-)
Add an exception to the `paperless-ng-server` service's
`SystemCallFilter` as the `mbind` syscall is needed when consuming a
document while having a classification model present.
As `nix-daemon.service` does not make use of `ExecStop`, we prefer
to keep the socket up and available. This is important for machines
that run Nix-based services, such as automated build, test, and deploy
services, that expect the daemon socket to be available at all times.
See committed inline comment for further explanation.
