nuc: add elbe pegel

hosts/nuc/modules/monitoring/default.nix

@@ -93,6 +93,19 @@ in
         enable = true;
         enabledCollectors = [ "systemd" ];
       };
+      json = {
+        enable = true;
+        configFile = pkgs.writeText "json-exporter.yml" ''
+          ---
+          modules:
+            pegelstand:
+              metrics:
+                - name: pegelstand_elbe_dresden
+                  path: '{ $.pegel }'
+                  type: value
+                  help: Pegelstand in Dresden
+        '';
+      };
     };
     scrapeConfigs = [
       {
@@ -127,6 +140,20 @@ in
           targets = [ "nuc.vpn.rfive.de:9300" ];
         }];
       }
+      {
+        job_name = "pegel_dresden";
+        metrics_path = "/probe";
+        params = {
+          module = [ "pegelstand" ];
+          target = [
+            "https://api.stramke.com/wasserstand/sachsen/Dresden"
+          ];
+        };
+        static_configs = [{
+          targets = [ "nuc.vpn.rfive.de:7979" ];
+        }];
+        scrape_interval = "5m";
+      }
       {
         job_name = "caddy";
         static_configs = [{