Disallow auto-reboot when users are active

hosts/Rupert.nix

@@ -119,6 +119,7 @@ in
         gitPull = true;
         gitDeploymentKeyFile = "/secrets/ssh_id_gitea_nixos_configuration";
         gitUser = "fruchti";
+        rebootIgnoreUsersActive = [ "waldi" ];
     };
 
     # systemd.services.nixos-upgrade.onFailure = lib.mkIf config.system.autoUpgrade.enable [ "status-email@%n.service" ];

hosts/burp-server.nix

@@ -19,6 +19,7 @@
             "Berthold"
             "Ernesto"
             "Emitter"
+            "Adelheid"
         ]);
         superClients = [
             config.networking.hostName

options/auto-upgrade.nix

@@ -36,6 +36,13 @@ in
                 User used for the `git pull` operation (if `gitPull` is enabled).
             '';
         };
+        rebootIgnoreUsersActive = mkOption {
+            type = types.listOf types.str;
+            default = [];
+            description = mdDoc ''
+                If reboots are allowed, active users will prohibit a reboot. Users listed here are ignored from that check.
+            '';
+        };
     };
 
     config = mkIf cfg.enable {
@@ -156,6 +163,14 @@ in
                 EOF
                         )"
                         activate_configuration="no"
+
+                        # Check if any user sessions are open
+                        active_users=$(users | tr ' ' '\n' | sort | uniq | grep -vE '^(${concatStringsSep "|" cfg.rebootIgnoreUsersActive})$')
+                        if [ "$reboot_allowed" = "yes" ] && [ -n "$active_users" ] ; then
+                            reboot_allowed=no
+                            email_body="$(printf "%s\n%s\n%s" "$email_body" "The system cannot reboot since the following users are active:" "$active_users")"
+                        fi
+
                         if [ "$reboot_allowed" = "yes" ] && [ $exit_code -eq 0 ] ; then
                             email_body="$(printf "%s\n%s" "$email_body" "The system will reboot now.")"
                             do_reboot="yes"