Add metrics host with Grafana and Prometheus

hosts/metrics/grafana.nix

@@ -1,11 +1,11 @@
-{ ... }:
+{ config, ... }:
 {
   services.grafana = {
     enable = true;
     settings = {
       server = {
-        domain = "grafana2.grzb.de";
-        root_url = "https://grafana2.grzb.de";
+        domain = "grafana.grzb.de";
+        root_url = "https://${config.services.grafana.settings.server.domain}";
       };
       security = {
         cookie_secure = true;
@@ -24,5 +24,13 @@
         startTLS_policy = "NoStartTLS";
       };
     };
+    provision.datasources.settings.datasources = [
+      {
+        name = "Prometheus";
+        type = "prometheus";
+        url = "http://localhost:${builtins.toString config.services.prometheus.port}";
+        isDefault = true;
+      }
+    ];
   };
 }

hosts/metrics/nginx.nix

@@ -3,7 +3,7 @@
   services.nginx = {
     enable = true;
     virtualHosts = {
-      "grafana2.grzb.de" = {
+      ${config.services.grafana.settings.server.domain} = {
         forceSSL = true;
         enableACME = true;
         listen = [
@@ -19,6 +19,7 @@
         ];
         locations."/" = {
           proxyPass = "http://${config.services.grafana.settings.server.http_addr}:${builtins.toString config.services.grafana.settings.server.http_port}";
+          proxyWebsockets = true;
         };
       };
     };

hosts/metrics/prometheus.nix

@@ -1,6 +1,19 @@
-{ ... }:
+{ hosts, ... }:
 {
   services.prometheus = {
     enable = true;
+    scrapeConfigs = [
+      {
+        job_name = "node";
+        static_configs = builtins.map (name: {
+          targets = [
+            "${name}.${hosts.${name}.site}.grzb.de:9100"
+          ];
+          labels = {
+            host = "${name}.${hosts.${name}.site}.grzb.de";
+          };
+        }) (builtins.attrNames hosts);
+      }
+    ];
   };
 }