Systemd/User Services
Systemd supports running a separate instance of systemd for a given user, allowing the user to control their own services. See here for more information: https://wiki.archlinux.org/title/Systemd/User
In NixOS, a user service can be expressed with systemd.user.services.<name>
, as documented here: https://search.nixos.org/options?query=systemd.user.services
This may be useful if you want a user to be able to start, stop, and restart their own instance of a service without needing to make the user a sudoer.
Here is an example:
systemd.user.services.my-cool-user-service = {
enable = true;
after = [ "network.target" ];
wantedBy = [ "default.target" ];
description = "My Cool User Service";
serviceConfig = {
Type = "simple";
ExecStart = ''/my/cool/user/service'';
};
};
By default, user services will be stopped when the user logs out and will start again when the user logs back in due to us setting wantedBy = [ "default.target" ]
in the example.
Keeping user services running after logout
If you need a user service to stay running after a user logs out, you need to enable "lingering" by setting users.users.<username>.linger = true;
You'll also likely want to change to wantedBy = [ "multi-user.target" ];
so the service starts at boot time.
Enabling a service for specific users
By default, enabling a user service enables it for every user for which systemd spawns a service manager. If you wish for the service to be run only for specific users (say, UserA
and UserB
), use ConditionUser
(man 5 systemd.unit
):
systemd.user.services.my-cool-user-service = {
unitConfig.ConditionUser = "UserA|UserB";
};