cluster/services/monitoring: make blackbox targets configurable through cluster config

cluster/services/monitoring/blackbox.nix

@@ -68,12 +68,7 @@ in
       };
     };
     blackbox_targets = let
-      regularTargets = mapTargets {
-        web = {
-          module = "https2xx";
-          address = "https://www.${domain}";
-        };
-      };
+      regularTargets = mapTargets cluster.config.monitoring.blackbox.targets;
       secretTargets = mkSecretTargets 1;
     in regularTargets ++ secretTargets;
   };

cluster/services/monitoring/default.nix

@@ -9,6 +9,10 @@ let
 in
 
 {
+  imports = [
+    ./options.nix
+  ];
+
   links = {
     loki-ingest = {
       protocol = "http";

cluster/services/monitoring/options.nix

@@ -0,0 +1,25 @@
+{ lib, ... }:
+with lib;
+
+{
+  options.monitoring = {
+    blackbox = {
+      targets = mkOption {
+        description = "Blackbox targets to be monitored by the cluster.";
+        default = {};
+        type = with types; attrsOf (submodule ({ ... }: {
+          options = {
+            module = mkOption {
+              description = "The Blackbox module to use.";
+              type = types.str;
+            };
+            address = mkOption {
+              description = "The target's address.";
+              type = types.str;
+            };
+          };
+        }));
+      };
+    };
+  };
+}