Add option to include message templates as an additional field

mattwcole · Aug 4, 2019 · adf9214 · adf9214
1 parent 1de9506
commit adf9214
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Showing 3 changed files with 43 additions and 9 deletions.
diff --git a/src/Gelf.Extensions.Logging/GelfLogger.cs b/src/Gelf.Extensions.Logging/GelfLogger.cs
@@ -4,7 +4,6 @@
 using System.Linq;
 using System.Text.RegularExpressions;
 using Microsoft.Extensions.Logging;
-using Microsoft.Extensions.Logging.Internal;
 
 namespace Gelf.Extensions.Logging
 {
@@ -17,7 +16,8 @@ public class GelfLogger : ILogger
             "logger",
             "exception",
             "event_id",
-            "event_name"
+            "event_name",
+            "message_template"
         };
 
         private readonly string _name;
@@ -113,8 +113,8 @@ public IDisposable BeginScope<TState>(TState state)
 
         private static IEnumerable<KeyValuePair<string, object>> GetStateAdditionalFields<TState>(TState state)
         {
-            return state is /*FormattedLogValues*/IEnumerable<KeyValuePair<string, object>> logValues
-                ? logValues.Take(logValues.Count() - 1)
+            return state is IEnumerable<KeyValuePair<string, object>> logValues
+                ? logValues
                 : Enumerable.Empty<KeyValuePair<string, object>>();
         }
 
@@ -137,18 +137,25 @@ private IEnumerable<KeyValuePair<string, object>> GetScopeAdditionalFields()
             return additionalFields.Reverse();
         }
 
-        private static IEnumerable<KeyValuePair<string, object>> ValidateAdditionalFields(
+        private IEnumerable<KeyValuePair<string, object>> ValidateAdditionalFields(
             IEnumerable<KeyValuePair<string, object>> additionalFields)
         {
             foreach (var field in additionalFields)
             {
-                if (AdditionalFieldKeyRegex.IsMatch(field.Key) && !ReservedAdditionalFieldKeys.Contains(field.Key))
+                if (field.Key != "{OriginalFormat}")
                 {
-                    yield return field;
+                    if (AdditionalFieldKeyRegex.IsMatch(field.Key) && !ReservedAdditionalFieldKeys.Contains(field.Key))
+                    {
+                        yield return field;
+                    }
+                    else
+                    {
+                        Debug.Fail($"GELF message has additional field with invalid key \"{field.Key}\".");
+                    }
                 }
-                else
+                else if (_options.IncludeMessageTemplates)
                 {
-                    Debug.Fail($"GELF message has additional field with invalid key \"{field.Key}\".");
+                    yield return new KeyValuePair<string, object>("message_template", field.Value);
                 }
             }
         }

diff --git a/src/Gelf.Extensions.Logging/GelfLoggerOptions.cs b/src/Gelf.Extensions.Logging/GelfLoggerOptions.cs
@@ -78,5 +78,10 @@ public GelfLoggerOptions()
         /// Timeout used when sending logs via HTTP(S).
         /// </summary>
         public TimeSpan HttpTimeout { get; set; } = TimeSpan.FromSeconds(30);
+
+        /// <summary>
+        /// Include a field with the original message template before structured log parameters are replaced.
+        /// </summary>
+        public bool IncludeMessageTemplates { get; set; }
     }
 }
diff --git a/test/Gelf.Extensions.Logging.Tests/GelfLoggerTests.cs b/test/Gelf.Extensions.Logging.Tests/GelfLoggerTests.cs
@@ -44,6 +44,7 @@ public async Task Sends_message_to_Graylog(LogLevel logLevel, int expectedLevel)
             Assert.Equal(expectedLevel, message.level);
             Assert.Equal(typeof(GelfLoggerTests).FullName, message.logger);
             Assert.Throws<RuntimeBinderException>(() => message.exception);
+            Assert.Throws<RuntimeBinderException>(() => message.message_template);
         }
 
         [Fact]
@@ -216,6 +217,27 @@ public async Task Ignores_null_values_in_additional_fields()
             }
         }
 
+        [Fact]
+        public async Task Sends_message_templates_when_enabled()
+        {
+            var options = LoggerFixture.LoggerOptions;
+            options.IncludeMessageTemplates = true;
+            options.AdditionalFields.Add("test_id", TestContext.TestId);
+
+            using (var loggerFactory = LoggerFixture.CreateLoggerFactory(options))
+            {
+                var messageTemplate = "This is a message template {foo} {bar}";
+                var sut = loggerFactory.CreateLogger(nameof(GelfLoggerTests));
+                sut.LogInformation(messageTemplate, "FOO", "BAR");
+
+                var message = await GraylogFixture.WaitForMessageAsync();
+
+                Assert.Equal(messageTemplate, message.message_template);
+                Assert.Equal("FOO", message.foo);
+                Assert.Equal("BAR", message.bar);
+            }
+        }
+
         public void Dispose()
         {
             LoggerFixture.Dispose();