User-defined log stream prefix (issue #83)

src/AWS.Logger.AspNetCore/AWSLoggerConfigSection.cs

@@ -62,6 +62,7 @@ public class AWSLoggerConfigSection
         internal const string LOG_LEVEL = "LogLevel";
         internal const string MAX_QUEUED_MESSAGES = "MaxQueuedMessages";
         internal const string LOG_STREAM_NAME_SUFFIX = "LogStreamNameSuffix";
+        internal const string LOG_STREAM_NAME_PREFIX = "LogStreamNamePrefix";
         internal const string LIBRARY_LOG_FILE_NAME = "LibraryLogFileName";
         internal const string INCLUDE_SCOPES_NAME = "IncludeScopes";
 
@@ -96,6 +97,10 @@ public AWSLoggerConfigSection(IConfiguration loggerConfigSection)
             {
                 Config.LogStreamNameSuffix = loggerConfigSection[LOG_STREAM_NAME_SUFFIX];
             }
+            if (loggerConfigSection[LOG_STREAM_NAME_PREFIX] != null)
+            {
+                Config.LogStreamNamePrefix = loggerConfigSection[LOG_STREAM_NAME_PREFIX];
+            }
             if (loggerConfigSection[LIBRARY_LOG_FILE_NAME] != null)
             {
                 Config.LibraryLogFileName = loggerConfigSection[LIBRARY_LOG_FILE_NAME];

src/AWS.Logger.Core/AWSLoggerConfig.cs

@@ -129,13 +129,23 @@ public AWSLoggerConfig(string logGroup)
         /// <summary>
         /// Gets and sets the LogStreamNameSuffix property. The LogStreamName consists of a DateTimeStamp as the prefix and a user defined suffix value that can 
         /// be set using the LogStreamNameSuffix property defined here.
-        /// The LogstreamName then follows the pattern '[DateTime.Now.ToString("yyyy/MM/ddTHH.mm.ss")]-[LogstreamNameSuffix]'
+        /// The LogstreamName then follows the pattern '[LogStreamNamePrefix]-[DateTime.Now.ToString("yyyy/MM/ddTHH.mm.ss")]-[LogStreamNameSuffix]'
         /// <para>
         /// The default is going to a Guid.
         /// </para>
         /// </summary>
         public string LogStreamNameSuffix { get; set; } = Guid.NewGuid().ToString();
 
+        /// <summary>
+        /// Gets and sets the LogStreamNamePrefix property. The LogStreamName consists of an optional user-defined LogStreamNamePrefix (that can be set here)
+        /// followed by a DateTimeStamp as the prefix, and a user defined suffix value
+        /// The LogstreamName then follows the pattern '[LogStreamNamePrefix]-[DateTime.Now.ToString("yyyy/MM/ddTHH.mm.ss")]-[LogStreamNameSuffix]'
+        /// <para>
+        /// The default is an empty string.
+        /// </para>
+        /// </summary>
+        public string LogStreamNamePrefix { get; set; } = string.Empty;
+
         /// <summary>
         /// Gets and sets the LibraryLogFileName property. This is the name of the file into which errors from the AWS.Logger.Core library will be wriiten into.
         /// <para>

src/AWS.Logger.Core/Core/AWSLoggerCore.cs

@@ -444,7 +444,7 @@ private async Task<string> LogEventTransmissionSetup(CancellationToken token)
                 }
             }
 
-            var currentStreamName = DateTime.Now.ToString("yyyy/MM/ddTHH.mm.ss") + " - " + _config.LogStreamNameSuffix;
+            var currentStreamName = GenerateStreamName();
 
             var streamResponse = await _client.CreateLogStreamAsync(new CreateLogStreamRequest
             {
@@ -461,6 +461,22 @@ private async Task<string> LogEventTransmissionSetup(CancellationToken token)
             return currentStreamName;
         }
 
+        /// <summary>
+        /// generate a logstream name
+        /// </summary>
+        /// <returns>logstream name that ALWAYS includes a unique date-based segment</returns>
+        private string GenerateStreamName()
+        {
+            var suffix = _config.LogStreamNameSuffix;
+            var prefix = _config.LogStreamNamePrefix ?? string.Empty;
+            if (!string.IsNullOrEmpty(prefix))
+            {
+                prefix += " - ";  //if there WAS a user-specified prefix, let's use it, followed by a separator
+            }
+
+            return prefix + DateTime.Now.ToString("yyyy/MM/ddTHH.mm.ss") + " - " + suffix;
+        }
+
         private static bool IsSuccessStatusCode(AmazonWebServiceResponse serviceResponse)
         {
             return (int)serviceResponse.HttpStatusCode >= 200 && (int)serviceResponse.HttpStatusCode <= 299;

src/AWS.Logger.Log4net/AWSAppender.cs

@@ -128,8 +128,8 @@ public int MaxQueuedMessages
         }
 
         /// <summary>
-        /// Gets and sets the LogStreamNameSuffix property. The LogStreamName consists of a DateTimeStamp as the prefix and a user defined suffix value that can 
-        /// be set using the LogStreamNameSuffix property defined here.
+        /// Gets and sets the LogStreamNameSuffix property. The LogStreamName consists of an optional user-defined prefix segment, then a DateTimeStamp as the
+        /// system-defined prefix segment, and a user defined suffix value that can be set using the LogStreamNameSuffix property defined here.
         /// <para>
         /// The default is going to a Guid.
         /// </para>
@@ -140,6 +140,19 @@ public string LogStreamNameSuffix
             set { _config.LogStreamNameSuffix = value; }
         }
 
+        /// <summary>
+        /// Gets and sets the LogStreamNamePrefix property. The LogStreamName consists of an optional user-defined prefix segment (defined here), then a
+        /// DateTimeStamp as the system-defined prefix segment, and a user defined suffix value that can be set using the LogStreamNameSuffix property.
+        /// <para>
+        /// The default will use an empty string for this user-defined portion, meaning the log stream name will start with the system-defined portion of the prefix (yyyy/MM/dd ... )
+        /// </para>
+        /// </summary>
+        public string LogStreamNamePrefix
+        {
+            get { return _config.LogStreamNamePrefix; }
+            set { _config.LogStreamNamePrefix = value; }
+        }
+
         /// <summary>
         /// Gets and sets the LibraryLogFileName property. This is the name of the file into which errors from the AWS.Logger.Core library will be wriiten into.
         /// <para>
@@ -173,6 +186,7 @@ public override void ActivateOptions()
                 BatchSizeInBytes = BatchSizeInBytes,
                 MaxQueuedMessages = MaxQueuedMessages,
 				LogStreamNameSuffix = LogStreamNameSuffix,
+                LogStreamNamePrefix = LogStreamNamePrefix,
 				LibraryLogFileName = LibraryLogFileName
             };
             _core = new AWSLoggerCore(config, "Log4net");

src/AWS.Logger.SeriLog/AWSLoggerSeriLogExtension.cs

@@ -18,6 +18,7 @@ public static class AWSLoggerSeriLogExtension
         internal const string BATCH_PUSH_SIZE_IN_BYTES = "Serilog:BatchPushSizeInBytes";
         internal const string MAX_QUEUED_MESSAGES = "Serilog:MaxQueuedMessages";
         internal const string LOG_STREAM_NAME_SUFFIX = "Serilog:LogStreamNameSuffix";
+        internal const string LOG_STREAM_NAME_PREFIX = "Serilog:LogStreamNamePrefix";
         internal const string LIBRARY_LOG_FILE_NAME = "Serilog:LibraryLogFileName";
 
         /// <summary>
@@ -58,6 +59,10 @@ public static LoggerConfiguration AWSSeriLog(
             {
                 config.LogStreamNameSuffix = configuration[LOG_STREAM_NAME_SUFFIX];
             }
+            if (configuration[LOG_STREAM_NAME_PREFIX] != null)
+            {
+                config.LogStreamNamePrefix = configuration[LOG_STREAM_NAME_PREFIX];
+            }
             if (configuration[LIBRARY_LOG_FILE_NAME] != null)
             {
                 config.LibraryLogFileName = configuration[LIBRARY_LOG_FILE_NAME];

src/NLog.AWS.Logger/AWSTarget.cs

@@ -132,8 +132,8 @@ public int MaxQueuedMessages
         }
 
         /// <summary>
-        /// Gets and sets the LogStreamNameSuffix property. The LogStreamName consists of a DateTimeStamp as the prefix and a user defined suffix value that can 
-        /// be set using the LogStreamNameSuffix property defined here.
+        /// Gets and sets the LogStreamNameSuffix property. The LogStreamName consists of an optional user-defined prefix segment, then a DateTimeStamp as the
+        /// system-defined prefix segment, and a user defined suffix value that can be set using the LogStreamNameSuffix property defined here.
         /// <para>
         /// The default is going to a Guid.
         /// </para>
@@ -144,6 +144,19 @@ public string LogStreamNameSuffix
             set { _config.LogStreamNameSuffix = value; }
         }
 
+        /// <summary>
+        /// Gets and sets the LogStreamNamePrefix property. The LogStreamName consists of an optional user-defined prefix segment (defined here), then a
+        /// DateTimeStamp as the system-defined prefix segment, and a user defined suffix value that can be set using the LogStreamNameSuffix property.
+        /// <para>
+        /// The default will use an empty string for this user-defined portion, meaning the log stream name will start with the system-defined portion of the prefix (yyyy/MM/dd ... )
+        /// </para>
+        /// </summary>
+        public string LogStreamNamePrefix
+        {
+            get { return _config.LogStreamNamePrefix; }
+            set { _config.LogStreamNamePrefix = value; }
+        }
+
         /// <summary>
         /// Gets and sets the LibraryLogFileName property. This is the name of the file into which errors from the AWS.Logger.Core library will be wriiten into.
         /// <para>
@@ -175,6 +188,7 @@ protected override void InitializeTarget()
                 BatchSizeInBytes = BatchSizeInBytes,
                 MaxQueuedMessages = MaxQueuedMessages,
                 LogStreamNameSuffix = RenderSimpleLayout(LogStreamNameSuffix, nameof(LogStreamNameSuffix)),
+                LogStreamNamePrefix = RenderSimpleLayout(LogStreamNamePrefix, nameof(LogStreamNamePrefix)),
                 LibraryLogFileName = LibraryLogFileName
             };
             _core = new AWSLoggerCore(config, "NLog");

test/AWS.Logger.AspNetCore.Tests/appsettings.json

@@ -3,6 +3,7 @@
     "LogGroup": "AWSILogger",
     "Region": "us-west-2",
     "LogStreamNameSuffix": "Custom",
+    "LogStreamNamePrefix": "CustomPrefix",
     "LogLevel": {
       "Default": "Debug",
       "System": "Information",

test/AWS.Logger.Log4Net.Tests/log4net.config

@@ -7,16 +7,17 @@
     <LogGroup>AWSLog4NetGroupLog4Net</LogGroup>
     <Region>us-west-2</Region>
     <LogStreamNameSuffix>Custom</LogStreamNameSuffix>
-      <layout type="log4net.Layout.PatternLayout">
+    <LogStreamNamePrefix>CustomPrefix</LogStreamNamePrefix>
+    <layout type="log4net.Layout.PatternLayout">
       <conversionPattern value="%-4timestamp [%thread] %-5level %logger %ndc - %message%newline" />
     </layout>
   </appender>
 
   <!-- Set root logger level to DEBUG and its only appender to A1 -->
-  
+
   <root>
     <level value ="DEBUG"/>
     <appender-ref ref="AWS" />
   </root>
-  
+
 </log4net>

test/AWS.Logger.NLog.Tests/Regular.config

@@ -5,7 +5,7 @@
     <add assembly ="NLog.AWS.Logger"/>
   </extensions>
   <targets>
-    <target name="AWSNLogGroup" type="AWSTarget" logGroup="AWSNLogGroup" region="us-west-2" logStreamNameSuffix="Custom"/>
+    <target name="AWSNLogGroup" type="AWSTarget" logGroup="AWSNLogGroup" region="us-west-2" logStreamNameSuffix="Custom" logStreamNamePrefix="CustomPrefix"/>
     <target name="loggerRegular" xsi:type="Console" layout="${callsite} ${message}" />
   </targets>
   <rules>

test/AWS.Logger.SeriLog.Tests/AWSSeriLogGroup.json

@@ -5,6 +5,7 @@
     "LogGroup": "AWSSeriLogGroup",
     "Region": "us-west-2",
     "LogStreamNameSuffix": "Custom",
+    "LogStreamNamePrefix": "CustomPrefix",
     "Enrich": [ "FromLogContext", "WithMachineName", "WithThreadId" ]
   }
 }

test/AWS.Logger.TestUtils/BaseTestClass.cs

@@ -19,6 +19,7 @@ public abstract class BaseTestClass : IClassFixture<TestFixture>
         public const int THREAD_COUNT = 2;
         public const string LASTMESSAGE = "LASTMESSAGE";
         public const string CUSTOMSTREAMSUFFIX = "Custom";
+        public const string CUSTOMSTREAMPREFIX = "CustomPrefix";
         public TestFixture _testFixture;
         public AmazonCloudWatchLogsClient Client;
 
@@ -105,12 +106,15 @@ protected void SimpleLoggingTest(string logGroupName)
 
                 var customStreamSuffix = describeLogstreamsResponse.LogStreams[0].LogStreamName.Split('-').Last().Trim();
                 Assert.Equal(CUSTOMSTREAMSUFFIX, customStreamSuffix);
+                var customStreamPrefix = describeLogstreamsResponse.LogStreams[0].LogStreamName.Split('-').First().Trim();
+                Assert.Equal(CUSTOMSTREAMPREFIX, customStreamPrefix);
             }
             Assert.Equal(SIMPLELOGTEST_COUNT, getLogEventsResponse.Events.Count());
 
 
             _testFixture.LogGroupNameList.Add(logGroupName);
         }
+
 
         protected void MultiThreadTestGroup(string logGroupName)
         {