add prometheus deluge exporter

CHANGELOG.md

@@ -18,6 +18,7 @@
 - Revert Loki to major version 2 because upgrading to version 3 required manual intervention as Loki
   refuses to start. So until this issue is tackled, reverting is the best immediate fix.
   See https://github.com/NixOS/nixpkgs/commit/8f95320f39d7e4e4a29ee70b8718974295a619f4
+- Add prometheus deluge exporter support. It just needs the `shb.deluge.prometheusScraperPasswordFile` option to be set.
 
 ## Other Changes
 

flake.nix

@@ -20,6 +20,10 @@
           url = "https://patch-diff.githubusercontent.com/raw/NixOS/nixpkgs/pull/315018.patch";
           hash = "sha256-8jcGyO/d+htfv/ZajxXh89S3OiDZAr7/fsWC1JpGczM=";
         })
+        (originPkgs.fetchpatch {
+          url = "https://github.com/NixOS/nixpkgs/pull/317107.patch";
+          hash = "sha256-/bFQVxQgrDrMlACQGWBpMk76+PaA5mP9HuWm9MwCs/0=";
+        })
       ];
       patchedNixpkgs = originPkgs.applyPatches {
         name = "nixpkgs-patched";

modules/services/deluge.nix

@@ -182,6 +182,12 @@ in
       type = lib.types.path;
     };
 
+    prometheusScraperPasswordFile = lib.mkOption {
+      description = "File containing password for prometheus scraper. Setting this option will activate the prometheus deluge exporter.";
+      type = lib.types.nullOr lib.types.path;
+      default = null;
+    };
+
     enabledPlugins = lib.mkOption {
       type = lib.types.listOf lib.types.str;
       description = ''
@@ -266,7 +272,9 @@ in
     systemd.services.deluged.preStart = lib.mkBefore (shblib.replaceSecrets {
       userConfig = cfg.extraUsers // {
         localclient.password.source = config.shb.deluge.localclientPasswordFile;
-      };
+      } // (lib.optionalAttrs (config.shb.deluge.prometheusScraperPasswordFile != null) {
+        prometheus_scraper.password.source = config.shb.deluge.prometheusScraperPasswordFile;
+      });
       resultPath = "${config.services.deluge.dataDir}/.config/deluge/authTemplate";
       generator = name: value: pkgs.writeText "delugeAuth" (authGenerator value);
     });
@@ -320,5 +328,24 @@ in
     };
   } {
     systemd.services.deluged.serviceConfig = cfg.extraServiceConfig;
-  }]);
+  } (lib.mkIf (config.shb.deluge.prometheusScraperPasswordFile != null) {
+    services.prometheus.exporters.deluge = {
+      enable = true;
+
+      delugeHost = "127.0.0.1";
+      delugePort = config.services.deluge.config.daemon_port;
+      delugeUser = "prometheus_scraper";
+      delugePasswordFile = config.shb.deluge.prometheusScraperPasswordFile;
+    };
+
+    services.prometheus.scrapeConfigs = [
+      {
+        job_name = "deluge";
+        static_configs = [{
+          targets = ["127.0.0.1:${toString config.services.prometheus.exporters.deluge.port}"];
+        }];
+      }
+    ];
+  })
+  ]);
 }

test/vm/deluge.nix

@@ -98,6 +98,21 @@ let
             raise Exception(f"result had an error {response['error']}")
     '';
 
+  prometheusTestScript = { nodes, ... }:
+    let
+      hasSSL = !(isNull nodes.server.shb.deluge.ssl);
+      proto_fqdn = if hasSSL then "https://${fqdn}" else "http://${fqdn}";
+    in
+    ''
+    server.wait_for_open_port(${toString nodes.server.services.prometheus.exporters.deluge.port})
+    with subtest("prometheus"):
+        response = server.succeed(
+            "curl -sSf "
+            + " http://localhost:${toString nodes.server.services.prometheus.exporters.deluge.port}/metrics"
+        )
+        print(response)
+    '';
+
   base = {
     imports = [
       (pkgs'.path + "/nixos/modules/profiles/headless.nix")
@@ -293,4 +308,27 @@ in
   #
   #   testScript = commonTestScript;
   # };
+
+  prometheus = pkgs.testers.runNixOSTest {
+    name = "deluge_https";
+
+    nodes.server = lib.mkMerge [
+      base
+      certs
+      basic
+      https
+      prometheus
+      {
+        options = {
+          shb.authelia = lib.mkOption { type = lib.types.anything; };
+        };
+      }
+    ];
+
+    nodes.client = {};
+
+    testScript = inputs:
+      (commonTestScript inputs)
+      + (prometheusTestScript inputs);
+  };
 }