odin: Enable prometheus node exporter and promtail

machines/odin/configuration.nix

@@ -15,6 +15,7 @@
     ./storage.nix
     ./network.nix
     ./virtualisation.nix
+    ./promtail
     ../../users/erwin
     ../../users/root
   ];
@@ -105,6 +106,12 @@
     lvm = {
       enable = true;
     };
+    prometheus.exporters = {
+      node = {
+        enable = true;
+        enabledCollectors = [ "systemd" ];
+      };
+    };
   };
 
   system.stateVersion = "24.05";

machines/odin/promtail/default.nix

@@ -0,0 +1,33 @@
+{
+  services.promtail = {
+    enable = true;
+    configuration = {
+      clients = [ { url = "http://saga:3100/loki/api/v1/push"; } ];
+      positions = {
+        filename = "/tmp/positions.yaml";
+      };
+      scrape_configs = [
+        {
+          job_name = "journal";
+          journal = {
+            labels = {
+              host = "odin";
+              job = "systemd-journal";
+            };
+            max_age = "12h";
+          };
+          relabel_configs = [
+            {
+              source_labels = [ "__journal__systemd_unit" ];
+              target_label = "unit";
+            }
+          ];
+        }
+      ];
+      server = {
+        grpc_listen_port = 0;
+        http_listen_port = 28183;
+      };
+    };
+  };
+}