Make new config options dynamic

docs/configuration.asciidoc

@@ -1078,9 +1078,11 @@ NOTE: Changing this configuration will overwrite the default value.
 [[config-transaction-name-groups]]
 ==== `TransactionNameGroups` (added[1.27.0])
 
-With this option, you can group transaction names that contain dynamic parts with a wildcard expression. For example, the pattern `GET /user/*/cart` would consolidate transactions, such as 'GET /users/42/cart' and 'GET /users/73/cart' into a single transaction name 'GET /users/*/cart', hence reducing the transaction name cardinality.
+<<dynamic-configuration, image:./images/dynamic-config.svg[] >>
+
+With this option, you can group transaction names that contain dynamic parts with a wildcard expression. For example, the pattern `GET /user/*/cart` would consolidate transactions, such as `GET /users/42/cart` and `GET /users/73/cart` into a single transaction name `GET /users/*/cart`, hence reducing the transaction name cardinality.
 
-This option supports the wildcard *, which matches zero or more characters. Examples: GET /foo/*/bar/*/baz*, *foo*. Matching is case insensitive by default. Prepending an element with (?-i) makes the matching case sensitive.
+This option supports the wildcard `*`, which matches zero or more characters. Examples: `GET /foo/*/bar/*/baz*``, `*foo*`. Matching is case insensitive by default. Prepending an element with (?-i) makes the matching case sensitive.
 
 [options="header"]
 |============
@@ -1118,8 +1120,9 @@ When this setting is `true`, the agent also adds the header `elasticapm-tracepar
 [[config-use-path-as-transaction-name]]
 ==== `UsePathAsTransactionName` (added[1.27.0])
 
-If set to `true`,
-transaction names of unsupported or partially-supported frameworks will be in the form of `$method $path` instead of just `$method unknown route`.
+<<dynamic-configuration, image:./images/dynamic-config.svg[] >>
+
+If set to `true`, transaction names of unsupported or partially-supported frameworks will be in the form of `$method $path` instead of just `$method unknown route`.
 
 WARNING: If your URLs contain path parameters like `/user/$userId`,
 you should be very careful when enabling this flag,
@@ -1412,12 +1415,12 @@ you must instead set the `LogLevel` for the internal APM logger under the `Loggi
 | <<config-stack-trace-limit,`StackTraceLimit`>> | Yes | Stacktrace, Performance
 | <<config-trace-context-ignore-sampled-false,`TraceContextIgnoreSampledFalse`>> | No | Core
 | <<config-transaction-ignore-urls,`TransactionIgnoreUrls`>>  | Yes | HTTP, Performance
-| <<config-transaction-name-groups,`TransactionNameGroups`>>  | No | HTTP
+| <<config-transaction-name-groups,`TransactionNameGroups`>>  | Yes | HTTP
 | <<config-transaction-max-spans,`TransactionMaxSpans`>>  | Yes | Core, Performance
 | <<config-transaction-sample-rate,`TransactionSampleRate`>> | Yes | Core, Performance
 | <<config-trace-continuation-strategy,`TraceContinuationStrategy`>> | Yes | HTTP, Performance
 | <<config-use-elastic-apm-traceparent-header,`UseElasticTraceparentHeader`>> | No | HTTP
-| <<config-use-path-as-transaction-name,`UsePathAsTransactionName`>>  | No | HTTP
+| <<config-use-path-as-transaction-name,`UsePathAsTransactionName`>>  | Yes | HTTP
 | <<config-use-windows-credentials,`UseWindowsCredentials`>> | No | Reporter
 | <<config-verify-server-cert,`VerifyServerCert`>> | No | Reporter
 

src/Elastic.Apm/BackendComm/CentralConfig/CentralConfiguration.cs

@@ -54,6 +54,8 @@ internal class CentralConfiguration : AbstractConfigurationReader, IConfiguratio
 				GetSimpleConfigurationValue(DynamicConfigurationOption.ExitSpanMinDuration, ParseExitSpanMinDuration);
 			TraceContinuationStrategy =
 				GetConfigurationValue(DynamicConfigurationOption.TraceContinuationStrategy, ParseTraceContinuationStrategy);
+			TransactionNameGroups = GetConfigurationValue(DynamicConfigurationOption.TransactionNameGroups, ParseTransactionNameGroups);
+			UsePathAsTransactionName = GetSimpleConfigurationValue(DynamicConfigurationOption.UsePathAsTransactionName, ParseUsePathAsTransactionName);
 		}
 
 		public string Description => $"Central configuration (ETag: `{ETag}')";
@@ -92,10 +94,14 @@ internal class CentralConfiguration : AbstractConfigurationReader, IConfiguratio
 
 		internal IReadOnlyList<WildcardMatcher> TransactionIgnoreUrls { get; private set; }
 
+		internal IReadOnlyCollection<WildcardMatcher> TransactionNameGroups { get; private set; }
+
 		internal int? TransactionMaxSpans { get; private set; }
 
 		internal double? TransactionSampleRate { get; private set; }
 
+		internal bool? UsePathAsTransactionName { get; private set; }
+
 		private CentralConfigurationKeyValue BuildKv(DynamicConfigurationOption option, string value) => new(option, value, Description);
 
 		private T GetConfigurationValue<T>(DynamicConfigurationOption option, Func<ConfigurationKeyValue, T> parser)

src/Elastic.Apm/BackendComm/CentralConfig/DynamicConfigurationOption.cs

@@ -30,8 +30,10 @@ internal enum DynamicConfigurationOption
 		StackTraceLimit = ConfigurationOption.StackTraceLimit,
 		TraceContinuationStrategy = ConfigurationOption.TraceContinuationStrategy,
 		TransactionIgnoreUrls = ConfigurationOption.TransactionIgnoreUrls,
+		TransactionNameGroups = ConfigurationOption.TransactionNameGroups,
 		TransactionMaxSpans = ConfigurationOption.TransactionMaxSpans,
 		TransactionSampleRate = ConfigurationOption.TransactionSampleRate,
+		UsePathAsTransactionName = ConfigurationOption.UsePathAsTransactionName
 	}
 
 	internal static class DynamicConfigurationExtensions
@@ -64,6 +66,8 @@ dynamicOption switch
 				TransactionIgnoreUrls => ConfigurationOption.TransactionIgnoreUrls,
 				TransactionMaxSpans => ConfigurationOption.TransactionMaxSpans,
 				TransactionSampleRate => ConfigurationOption.TransactionSampleRate,
+				TransactionNameGroups => ConfigurationOption.TransactionNameGroups,
+				UsePathAsTransactionName => ConfigurationOption.UsePathAsTransactionName,
 				_ => throw new ArgumentOutOfRangeException(nameof(dynamicOption), dynamicOption, null)
 			};
 
@@ -75,7 +79,7 @@ option switch
 				ConfigurationOption.CaptureHeaders => CaptureHeaders,
 				ConfigurationOption.ExitSpanMinDuration => ExitSpanMinDuration,
 				ConfigurationOption.IgnoreMessageQueues => IgnoreMessageQueues,
-				ConfigurationOption.LogLevel => DynamicConfigurationOption.LogLevel,
+				ConfigurationOption.LogLevel => LogLevel,
 				ConfigurationOption.Recording => Recording,
 				ConfigurationOption.SanitizeFieldNames => SanitizeFieldNames,
 				ConfigurationOption.SpanCompressionEnabled => SpanCompressionEnabled,
@@ -90,6 +94,8 @@ option switch
 				ConfigurationOption.TransactionIgnoreUrls => TransactionIgnoreUrls,
 				ConfigurationOption.TransactionMaxSpans => TransactionMaxSpans,
 				ConfigurationOption.TransactionSampleRate => TransactionSampleRate,
+				ConfigurationOption.TransactionNameGroups => TransactionNameGroups,
+				ConfigurationOption.UsePathAsTransactionName => UsePathAsTransactionName,
 				_ => null
 			};
 
@@ -101,7 +107,7 @@ dynamicOption switch
 				CaptureHeaders => "capture_headers",
 				ExitSpanMinDuration => "exit_span_min_duration",
 				IgnoreMessageQueues => "ignore_message_queues",
-				DynamicConfigurationOption.LogLevel => "log_level",
+				LogLevel => "log_level",
 				Recording => "recording",
 				SanitizeFieldNames => "sanitize_field_names",
 				SpanCompressionEnabled => "span_compression_enabled",
@@ -116,6 +122,8 @@ dynamicOption switch
 				TransactionIgnoreUrls => "transaction_ignore_urls",
 				TransactionMaxSpans => "transaction_max_spans",
 				TransactionSampleRate => "transaction_sample_rate",
+				TransactionNameGroups => "transaction_name_groups",
+				UsePathAsTransactionName => "use_path_as_transaction_name",
 				_ => throw new ArgumentOutOfRangeException(nameof(dynamicOption), dynamicOption, null)
 			};
 	}

src/Elastic.Apm/BackendComm/CentralConfig/RuntimeConfigurationSnapshot.cs

@@ -118,15 +118,15 @@ internal RuntimeConfigurationSnapshot(IConfigurationReader mainConfiguration, Ce
 			_dynamicConfiguration?.TransactionIgnoreUrls ?? _mainConfiguration.TransactionIgnoreUrls;
 
 		public IReadOnlyCollection<WildcardMatcher> TransactionNameGroups =>
-			_mainConfiguration.TransactionNameGroups;
+			 _dynamicConfiguration?.TransactionNameGroups ?? _mainConfiguration.TransactionNameGroups;
 
 		public int TransactionMaxSpans => _dynamicConfiguration?.TransactionMaxSpans ?? _mainConfiguration.TransactionMaxSpans;
 
 		public double TransactionSampleRate => _dynamicConfiguration?.TransactionSampleRate ?? _mainConfiguration.TransactionSampleRate;
 
 		public bool UseElasticTraceparentHeader => _mainConfiguration.UseElasticTraceparentHeader;
 
-		public bool UsePathAsTransactionName => _mainConfiguration.UsePathAsTransactionName;
+		public bool UsePathAsTransactionName => _dynamicConfiguration?.UsePathAsTransactionName ?? _mainConfiguration.UsePathAsTransactionName;
 
 		public bool VerifyServerCert => _mainConfiguration.VerifyServerCert;
 	}

test/Elastic.Apm.Tests/BackendCommTests/CentralConfig/CentralConfigResponseParserTests.cs

@@ -169,6 +169,8 @@ public void ParseHttpResponse_ShouldReturnEmptyConfigDelta_WhenResponseBodyIsEmp
 			configDelta.LogLevel.Should().BeNull();
 			configDelta.SpanFramesMinDurationInMilliseconds.Should().BeNull();
 			configDelta.StackTraceLimit.Should().BeNull();
+			configDelta.TransactionNameGroups.Should().BeNull();
+			configDelta.UsePathAsTransactionName.Should().BeNull();
 		}
 
 		[Fact]
@@ -307,6 +309,29 @@ public static IEnumerable<object[]> ConfigDeltaData
 						})
 					};
 				}
+
+				yield return new object[]
+				{
+					$"{{\"{DynamicConfigurationOption.UsePathAsTransactionName.ToJsonKey()}\": \"{true}\"}}",
+					new Action<CentralConfiguration>(cfg =>
+					{
+						cfg.UsePathAsTransactionName.Should()
+							.NotBeNull()
+							.And.Be(true);
+					})
+				};
+
+				var transactionNameGroups = "GET /customers/*, GET /orders/*";
+				yield return new object[]
+				{
+					$"{{\"{DynamicConfigurationOption.TransactionNameGroups.ToJsonKey()}\": \"{transactionNameGroups}\"}}",
+					new Action<CentralConfiguration>(cfg =>
+					{
+						cfg.TransactionNameGroups.Should()
+							.NotBeNull()
+							.And.HaveCount(2);
+					})
+				};
 			}
 		}