New: Old/Obsolete Indexer Check

src/NzbDrone.Core/HealthCheck/Checks/OutdatedDefinitionCheck.cs

@@ -0,0 +1,46 @@
+using System.Linq;
+using NLog;
+using NzbDrone.Core.Indexers;
+using NzbDrone.Core.Indexers.Cardigann;
+using NzbDrone.Core.IndexerVersions;
+using NzbDrone.Core.Localization;
+using NzbDrone.Core.ThingiProvider.Events;
+
+namespace NzbDrone.Core.HealthCheck.Checks
+{
+    [CheckOn(typeof(ProviderDeletedEvent<IIndexer>))]
+    public class OutdatedDefinitionCheck : HealthCheckBase
+    {
+        private readonly IIndexerDefinitionUpdateService _indexerDefinitionUpdateService;
+        private readonly IIndexerFactory _indexerFactory;
+        private readonly Logger _logger;
+
+        public OutdatedDefinitionCheck(IIndexerDefinitionUpdateService indexerDefinitionUpdateService, IIndexerFactory indexerFactory, ILocalizationService localizationService, Logger logger)
+            : base(localizationService)
+        {
+            _indexerDefinitionUpdateService = indexerDefinitionUpdateService;
+            _indexerFactory = indexerFactory;
+            _logger = logger;
+        }
+
+        public override HealthCheck Check()
+        {
+            var blacklist = _indexerDefinitionUpdateService.GetBlacklist();
+
+            var oldIndexers = _indexerFactory.All().Where(i => i.Implementation == "Cardigann" && blacklist.Contains(((CardigannSettings)i.Settings).DefinitionFile)).ToList();
+
+            if (oldIndexers.Count == 0)
+            {
+                return new HealthCheck(GetType());
+            }
+
+            return new HealthCheck(GetType(),
+                HealthCheckResult.Warning,
+                string.Format(_localizationService.GetLocalizedString("IndexerObsoleteCheckMessage"),
+                string.Join(", ", oldIndexers.Select(v => v.Name))),
+                "#indexers-are-obsolete");
+        }
+
+        public override bool CheckOnSchedule => false;
+    }
+}

src/NzbDrone.Core/IndexerVersions/IndexerDefinitionUpdateService.cs

@@ -18,6 +18,7 @@ namespace NzbDrone.Core.IndexerVersions
     {
         List<CardigannMetaDefinition> All();
         CardigannDefinition GetDefinition(string fileKey);
+        List<string> GetBlacklist();
     }
 
     public class IndexerDefinitionUpdateService : IIndexerDefinitionUpdateService, IExecute<IndexerDefinitionUpdateCommand>
@@ -79,6 +80,11 @@ namespace NzbDrone.Core.IndexerVersions
             return definition;
         }
 
+        public List<string> GetBlacklist()
+        {
+            return _defintionBlacklist;
+        }
+
         private CardigannDefinition GetHttpDefinition(string id)
         {
             var req = new HttpRequest($"https://indexers.prowlarr.com/master/{DEFINITION_VERSION}/{id}");

src/NzbDrone.Core/Localization/Core/en.json

@@ -82,6 +82,7 @@
   "DevelopmentSettings": "Development Settings",
   "Disabled": "Disabled",
   "Docker": "Docker",
+  "IndexerObsoleteCheckMessage": "Indexers are obsolete or have been updated: {0}. Please remove and (or) re-add to Prowlarr",
   "DownloadClient": "Download Client",
   "DownloadClientCheckNoneAvailableMessage": "No download client is available",
   "DownloadClientCheckUnableToCommunicateMessage": "Unable to communicate with {0}.",