refactor monitoring module to allow kicking out inactive systems

modules/TLMS/default.nix

@@ -7,6 +7,6 @@
       ./json.nix
       ./net.nix
       ./wg.nix
-      ./node-exporter.nix
+      ./monitoring.nix
     ];
 }

modules/TLMS/monitoring.nix

@@ -0,0 +1,45 @@
+{ lib, config, ... }:
+let
+  cfg = config.deployment-TLMS.monitoring;
+in
+{
+  options.deployment-TLMS.monitoring = with lib; {
+    enable = mkOption {
+      type = types.bool;
+      default = true;
+      description = ''
+        Whether to enable TLMS default prometheus exporter and log collection
+      '';
+    };
+    monitoring.node-exporter = with lib; {
+      port = mkOption {
+        type = types.port;
+        default = 8119;
+        description = ''
+          Default port for prometheus node exporter to listen to
+        '';
+      };
+    };
+  };
+
+  config =
+    let
+      wg-addr-pred = !isNull config.deployment-TLMS.net.wg.addr4;
+      check-wg = enabled:
+        lib.assertMsg (enabled && wg-addr-pred)
+          ''For monitoring to be working the system must be in wireguard. See config.deplayment-TLMS.net.wg'';
+    in
+    lib.mkIf (check-wg cfg.enable) {
+      # prometheus node exporter
+      services.prometheus.exporters = {
+        node = {
+          enable = true;
+          port = 8119;
+          listenAddress = config.deployment-TLMS.net.wg.addr4;
+          enabledCollectors = [
+            "systemd"
+          ];
+        };
+      };
+    };
+}

modules/TLMS/node-exporter.nix

@@ -1,14 +0,0 @@
-{ config, ... }:
-{
-  # metrics exporter
-  services.prometheus.exporters = {
-    node = {
-      enable = true;
-      port = 8119;
-      listenAddress = config.deployment-TLMS.net.wg.addr4;
-      enabledCollectors = [
-        "systemd"
-      ];
-    };
-  };
-}