switch from netdata to grafana

modules/services/prometheus.nix

@@ -0,0 +1,31 @@
+{ config, pkgs, lib, ... }: {
+
+  options.metricsServer = lib.mkOption {
+    type = lib.types.str;
+    description = "Hostname of the Grafana server.";
+    default = "grafana.masu.rs";
+  };
+
+  config = {
+
+    services.grafana.enable = true;
+    services.prometheus = {
+      enable = true;
+      exporters.node.enable = true;
+      scrapeConfigs = [{
+        job_name = "local";
+        static_configs = [{ targets = [ "127.0.0.1:9100" ]; }];
+      }];
+    };
+
+    caddyRoutes = [{
+      match = [{ host = [ config.metricsServer ]; }];
+      handle = [{
+        handler = "reverse_proxy";
+        upstreams = [{ dial = "localhost:3000"; }];
+      }];
+    }];
+
+  };
+
+}