Added tagging feature

Author: zbalkan

Apps/LogExporterApp/App.cs

@@ -378,6 +378,10 @@ private void ConfigurePipeline()
             {
                 _enrichmentDispatcher.Add(new Normalize());
             }
+            if (_config!.Pipeline.TaggingProcessConfig?.Enabled is true)
+            {
+                _enrichmentDispatcher.Add(new Tags(_config.Pipeline.TaggingProcessConfig.Tags));
+            }
         }
 
         private void IncrementDropAndMaybeLog()

Apps/LogExporterApp/AppConfig.cs

@@ -144,10 +144,19 @@ public class PipelineConfig
         [JsonPropertyName("normalize")]
         public NormalizeProcess NormalizeProcessConfig { get; set; }
 
+        [JsonPropertyName("tagging")]
+        public TaggingProcess TaggingProcessConfig {  get; set; }
+
         public class NormalizeProcess : FeatureBase
-        {
+        {}
 
+        public class TaggingProcess : FeatureBase
+        {
+            [Required(ErrorMessage = "tags are required when tagging is enabled.")]
+            [JsonPropertyName("tags")]
+            public List<string> Tags { get; set; } = new List<string>();
         }
+
     }
     /// <summary>
     /// Shared serializer configuration for reading dnsApp.config.

Apps/LogExporterApp/Pipeline/Tags.cs

@@ -0,0 +1,45 @@
+/*
+Technitium DNS Server
+Copyright (C) 2025  Shreyas Zare (shreyas@technitium.com)
+Copyright (C) 2025  Zafer Balkan (zafer@zaferbalkan.com)
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace LogExporter.Pipeline
+{
+    public partial class Tags : IPipelineProcessor
+    {
+        private readonly string[] _tags; 
+        public Tags(IEnumerable<string> tags)
+        {
+            _tags = tags.ToArray();
+        }
+
+        public void Process(LogEntry logEntry)
+        {
+            logEntry.Meta["tags"] = _tags;
+        }
+
+        public void Dispose()
+        {
+            // If DomainCache ever needs disposal, do it here.
+            GC.SuppressFinalize(this);
+        }
+    }
+}

Apps/LogExporterApp/dnsApp.config

@@ -23,9 +23,13 @@
         "enabled": false
       }
   },
-  "pipeline":{
+  "pipeline": {
       "normalize": {
         "enabled": true
+      },
+      "tagging":{
+          "enabled": false,
+          "tags": [ "tenant:alpha" ]
       }
   }
 }