prometheus: added but not enabled yet

options/services.nix

@@ -55,6 +55,10 @@ in
         type = types.bool;
         default = config.profile.services.telemetry.enable;
       };
+      prometheus.enable = mkOption {
+        type = types.bool;
+        default = config.profile.services.telemetry.enable;
+      };
     };
   };
 }

system/services/telemetry/alloy.nix

@@ -3,7 +3,6 @@ let
   cfg = config.profile.services.telemetry.alloy;
   webguiListenAddress = "0.0.0.0:5319";
   domain = "alloy.tigor.web.id";
-  inherit (lib.strings) optionalString;
 in
 {
   imports = [

system/services/telemetry/default.nix

@@ -6,5 +6,6 @@
     ./tempo.nix
     ./alloy.nix
     ./mimir.nix
+    ./prometheus.nix
   ];
 }

system/services/telemetry/prometheus.nix

@@ -0,0 +1,50 @@
+{ config, lib, ... }:
+let
+  cfg = config.profile.services.telemetry.prometheus;
+  inherit (lib) mkIf;
+in
+{
+  config = mkIf cfg.enable {
+    services.prometheus = {
+      enable = false;
+      port = 0; # Random
+      enableAgentMode = true;
+      globalConfig = {
+        external_labels = {
+          instance = "homeserver";
+        };
+      };
+      remoteWrite =
+        let
+          mimirServer = config.services.mimir.configuration.server;
+        in
+        [
+          {
+            url = "http://${mimirServer.http_listen_address}:${toString mimirServer.http_listen_port}/api/v1/push";
+          }
+        ];
+      scrapeConfigs = [
+        {
+          job_name = "systemd";
+          static_configs = [{
+            labels = {
+              job = "systemd";
+            };
+            targets =
+              let
+                systemdExporter = config.services.prometheus.exporters.systemd;
+              in
+              [
+                "${systemdExporter.listenAddress}:${toString systemdExporter.port}"
+              ];
+          }];
+        }
+      ];
+      exporters = {
+        systemd = {
+          enable = true;
+        };
+      };
+    };
+  };
+}