nixos/tests/prometheus-exporters: add exportarr-sonarr test (#285119)

nixos/tests/prometheus-exporters.nix

@@ -356,6 +356,46 @@ let
       '';
     };
 
+    exportarr-sonarr = let apikey = "eccff6a992bc2e4b88e46d064b26bb4e"; in {
+      nodeName = "exportarr_sonarr";
+      exporterConfig = {
+        enable = true;
+        url = "http://127.0.0.1:8989";
+        apiKeyFile = pkgs.writeText "dummy-api-key" apikey;
+      };
+      metricProvider = {
+        services.sonarr.enable = true;
+        systemd.services.sonarr.serviceConfig.ExecStartPre =
+          let
+            sonarr_config = pkgs.writeText "config.xml" ''
+              <Config>
+                <LogLevel>info</LogLevel>
+                <EnableSsl>False</EnableSsl>
+                <Port>8989</Port>
+                <SslPort>9898</SslPort>
+                <UrlBase></UrlBase>
+                <BindAddress>*</BindAddress>
+                <ApiKey>${apikey}</ApiKey>
+                <AuthenticationMethod>None</AuthenticationMethod>
+                <UpdateMechanism>BuiltIn</UpdateMechanism>
+                <Branch>main</Branch>
+                <InstanceName>Sonarr</InstanceName>
+              </Config>
+            '';
+          in
+          [
+            ''${pkgs.coreutils}/bin/install -D -m 777 ${sonarr_config} -T /var/lib/sonarr/.config/NzbDrone/config.xml''
+          ];
+      };
+      exporterTest = ''
+        wait_for_unit("sonarr.service")
+        wait_for_open_port(8989)
+        wait_for_unit("prometheus-exportarr-sonarr-exporter.service")
+        wait_for_open_port(9708)
+        succeed("curl -sSf http://localhost:9708/metrics | grep sonarr_series_total")
+      '';
+    };
+
     fastly = {
       exporterConfig = {
         enable = true;