Loki: add prometheus

instances/loki/configuration.nix

@@ -470,6 +470,28 @@ in
     ];
   };
 
+  servies.prometheus = {
+    enable = true;
+    exporters = {
+      node = { enable = true; enabledCollectors = [ "systemd" ]; };
+      process = {
+        enable = true;
+        settings.process_names = [
+          # Remove nix store path from process name
+          { name = "{{.Matches.Wrapped}} {{ .Matches.Args }}"; cmdline = [ "^/nix/store[^ ]*/(?P<Wrapped>[^ /]*) (?P<Args>.*)" ]; }
+        ];
+      };
+      systemd.enable = true;
+    };
+    globalConfig = { scrape_interval = "10s"; };
+    scrapeConfigs = [
+      { job_name = "node"; static_configs = [{ targets = [ "localhost:${toString config.services.prometheus.exporters.node.port}" ]; }]; }
+      { job_name = "process"; static_configs = [{ targets = [ "localhost:${toString config.services.prometheus.exporters.process.port}" ]; }]; }
+      { job_name = "systemd"; static_configs = [{ targets = [ "localhost:${toString config.services.prometheus.exporters.systemd.port}" ]; }]; }
+    ];
+    retentionTime = "15d";
+  };
+
   security.sudo.extraConfig = ''
     Defaults pwfeedback
   '';