add ups periodic checks

modules/default.nix

@@ -76,6 +76,10 @@ package:
           warning_threshold_comb_bytes = interfaceCfg.warningThresholdCombBytes;
           critical_threshold_comb_bytes = interfaceCfg.criticalThresholdCombBytes;
         }) cfg.checks.net.interfaces;
+
+        ups = with cfg.checks.ups; {
+          ups_to_check = upsToCheck;
+        };
       };
     };
   in lib.mkIf cfg.enable {

modules/options.nix

@@ -33,6 +33,7 @@ in
         "ram"
         "temp"
         "net"
+        "ups"
 
         "vulnix"
       ]);
@@ -45,6 +46,7 @@ in
         * ram -- alerts when RAM usage is above threshold
         * temp -- alerts when temperature readings are above thresholds
         * net -- alerts when network usage is above threshold
+        * ups -- alerts on UPS events
         * vulnix -- periodically scans system for known CVEs, alerts if any are found (NixOS only)'';
     };
 
@@ -170,6 +172,14 @@ in
             }'';
         };
       };
+
+      ups = {
+        upsToCheck = lib.mkOption {
+          type = with lib.types; nullOr (listOf str);
+          default = null;
+          description = "List of UPS's to monitor, in `upsc`-compatible format. If null, all UPS's connected to localhost are checked.";
+        };
+      };
     };
   };
 }