NLogLoggingConfiguration - Support KeepVariablesOnReload (#286)

NLog · Apr 28, 2019 · 1e5180d · 1e5180d
1 parent cef73eb
commit 1e5180d
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Showing 2 changed files with 35 additions and 9 deletions.
diff --git a/src/NLog.Extensions.Logging/Config/NLogLoggingConfiguration.cs b/src/NLog.Extensions.Logging/Config/NLogLoggingConfiguration.cs
@@ -97,8 +97,14 @@ private void ReloadConfigurationSection(IConfigurationSection nlogConfig)
 
                 InternalLogger.Info("Reloading NLogLoggingConfiguration...");
                 var newConfig = new NLogLoggingConfiguration(nlogConfig, LogFactory);
-                if (LogFactory.Configuration != null)
+                var oldConfig = LogFactory.Configuration;
+                if (oldConfig != null)
                 {
+                    if (LogFactory.KeepVariablesOnReload)
+                    {
+                        foreach (var variable in oldConfig.Variables)
+                            newConfig.Variables[variable.Key] = variable.Value;
+                    }
                     LogFactory.Configuration = newConfig;
                 }
             }

diff --git a/test/NLog.Extensions.Logging.Tests/NLogLoggingConfigurationTests.cs b/test/NLog.Extensions.Logging.Tests/NLogLoggingConfigurationTests.cs
@@ -108,14 +108,14 @@ public void LoadDefaultTargetParametersJsonLayoutConfig()
         {
             var memoryConfig = CreateMemoryConfigConsoleTargetAndRule();
             memoryConfig["NLog:Targets:file:type"] = "File";
-            memoryConfig["NLog:Default-target-parameters:file:filename"] = "hello.txt";
-            memoryConfig["NLog:Default-target-parameters:file:layout:type"] = "JsonLayout";
-            memoryConfig["NLog:Default-target-parameters:file:layout:Attributes:0:name"] = "timestamp";
-            memoryConfig["NLog:Default-target-parameters:file:layout:Attributes:0:layout"] = "${date:format=o}";
-            memoryConfig["NLog:Default-target-parameters:file:layout:Attributes:1:name"] = "level";
-            memoryConfig["NLog:Default-target-parameters:file:layout:Attributes:1:layout"] = "${level}";
-            memoryConfig["NLog:Default-target-parameters:file:layout:Attributes:2:name"] = "message";
-            memoryConfig["NLog:Default-target-parameters:file:layout:Attributes:2:layout"] = "${message}";
+            memoryConfig["NLog:default-target-parameters:file:filename"] = "hello.txt";
+            memoryConfig["NLog:default-target-parameters:file:layout:type"] = "JsonLayout";
+            memoryConfig["NLog:default-target-parameters:file:layout:Attributes:0:name"] = "timestamp";
+            memoryConfig["NLog:default-target-parameters:file:layout:Attributes:0:layout"] = "${date:format=o}";
+            memoryConfig["NLog:default-target-parameters:file:layout:Attributes:1:name"] = "level";
+            memoryConfig["NLog:default-target-parameters:file:layout:Attributes:1:layout"] = "${level}";
+            memoryConfig["NLog:default-target-parameters:file:layout:Attributes:2:name"] = "message";
+            memoryConfig["NLog:default-target-parameters:file:layout:Attributes:2:layout"] = "${message}";
 
             var logConfig = CreateNLogLoggingConfigurationWithNLogSection(memoryConfig);
 
@@ -150,6 +150,26 @@ private void ReloadLogFactoryConfiguration()
             configuration.Reload(); // Nothing should happen
         }
 
+        [Fact]
+        private void ReloadLogFactoryConfigurationKeepVariables()
+        {
+            var memoryConfig = CreateMemoryConfigConsoleTargetAndRule();
+            memoryConfig["NLog:Targets:file:type"] = "File";
+            memoryConfig["NLog:Targets:file:fileName"] = "${var:var_filename}";
+            memoryConfig["NLog:autoreload"] = "true";
+            memoryConfig["NLog:KeepVariablesOnReload"] = "true";
+            memoryConfig["NLog:variables:var_filename"] = "hello.txt";
+            var configuration = new ConfigurationBuilder().AddInMemoryCollection(memoryConfig).Build();
+            var logFactory = new LogFactory();
+            var logConfig = new NLogLoggingConfiguration(configuration.GetSection("NLog"), logFactory);
+            logFactory.Configuration = logConfig;
+            Assert.Equal("hello.txt", (logFactory.Configuration.FindTargetByName("file") as FileTarget)?.FileName.Render(LogEventInfo.CreateNullEvent()));
+            logFactory.Configuration.Variables["var_filename"] = "updated.txt";
+            Assert.Equal("updated.txt", (logFactory.Configuration.FindTargetByName("file") as FileTarget)?.FileName.Render(LogEventInfo.CreateNullEvent()));
+            configuration.Reload(); // Automatic Reload
+            Assert.Equal("updated.txt", (logFactory.Configuration.FindTargetByName("file") as FileTarget)?.FileName.Render(LogEventInfo.CreateNullEvent()));
+        }
+
         private static NLogLoggingConfiguration CreateNLogLoggingConfigurationWithNLogSection(IDictionary<string, string> memoryConfig)
         {
             var configuration = new ConfigurationBuilder().AddInMemoryCollection(memoryConfig).Build();