dns: Add prometheus exporter

machines/renge/services/prometheus.nix

@@ -123,6 +123,18 @@ in
           replacement = "vueko.sbruder.de";
         };
       }
+      {
+        job_name = "knot";
+        static_configs = mkStaticTargets [
+          "okarin.vpn.sbruder.de:9433"
+          "vueko.vpn.sbruder.de:9433"
+        ];
+        relabel_configs = lib.singleton {
+          target_label = "instance";
+          source_labels = lib.singleton "__address__";
+          regex = "(.*)\\.vpn\\.sbruder\\.de:9433";
+        };
+      }
     ];
 
     rules =

modules/authoritative-dns.nix

@@ -41,6 +41,15 @@ in
         log:
           - target: syslog
             any: info
+
+        mod-stats:
+          - id: custom
+            edns-presence: on
+            flag-presence: on
+            query-size: on
+            query-type: on
+            reply-size: on
+
         remote:
         ${lib.concatStrings (lib.mapAttrsToList (host: hostAddresses: ''
           - id: ${host}
@@ -70,6 +79,8 @@ in
             # dnssec
             dnssec-signing: on
             dnssec-policy: default
+            # stats
+            module: mod-stats/custom
           - id: nix-generated
             storage: /var/lib/knot/nix-zones/
             semantic-checks: on
@@ -77,6 +88,8 @@ in
             zonefile-sync: -1
             zonefile-load: difference-no-serial
             journal-content: all
+            # stats
+            module: mod-stats/custom
 
         zone:
         ${lib.concatMapStrings (domain: ''
@@ -93,6 +106,8 @@ in
           - id: default
             master: [${primaryHost}]
             acl: [primary_notify]
+            # stats
+            module: mod-stats/custom
       '');
     };
 
@@ -167,6 +182,11 @@ in
       allowedUDPPorts = [ 53 ];
     };
 
+    services.prometheus.exporters.knot = {
+      enable = true;
+      listenAddress = config.sbruder.wireguard.home.address;
+    };
+
     assertions = [
       {
         assertion = isPrimaryHost -> (lib.hasAttr "vpn.sbruder.de" cfg.generated-zones);