Set the frame type for JSON logging when sending JSON logs to Lambda telemetry API

Author: normj

Libraries/src/Amazon.Lambda.RuntimeSupport/Bootstrap/Constants.cs

@@ -33,6 +33,14 @@ internal class Constants
         internal const string AWS_LAMBDA_INITIALIZATION_TYPE_PC = "provisioned-concurrency";
         internal const string AWS_LAMBDA_INITIALIZATION_TYPE_ON_DEMAND = "on-demand";
 
+        internal const string NET_RIC_LOG_LEVEL_ENVIRONMENT_VARIABLE = "AWS_LAMBDA_HANDLER_LOG_LEVEL";
+        internal const string NET_RIC_LOG_FORMAT_ENVIRONMENT_VARIABLE = "AWS_LAMBDA_HANDLER_LOG_FORMAT";
+
+        internal const string LAMBDA_LOG_LEVEL_ENVIRONMENT_VARIABLE = "AWS_LAMBDA_LOG_LEVEL";
+        internal const string LAMBDA_LOG_FORMAT_ENVIRONMENT_VARIABLE = "AWS_LAMBDA_LOG_FORMAT";
+
+        internal const string LAMBDA_LOG_FORMAT_JSON = "Json";
+
         internal enum AwsLambdaDotNetPreJit
         {
             Never,

Libraries/src/Amazon.Lambda.RuntimeSupport/Client/IRuntimeApiClient.cs

@@ -13,6 +13,7 @@
  * permissions and limitations under the License.
  */
 
+using Amazon.Lambda.RuntimeSupport.Helpers;
 using System;
 using System.IO;
 using System.Threading;
@@ -25,6 +26,11 @@ namespace Amazon.Lambda.RuntimeSupport
     /// </summary>
     public interface IRuntimeApiClient
     {
+        /// <summary>
+        /// Logger used for formatting log messages into the user's CloudWatch Log stream.
+        /// </summary>
+        IConsoleLoggerWriter ConsoleLogger { get; }
+
         /// <summary>
         /// Report an initialization error as an asynchronous operation.
         /// </summary>

Libraries/src/Amazon.Lambda.RuntimeSupport/Client/RuntimeApiClient.cs

@@ -39,6 +39,9 @@ public class RuntimeApiClient : IRuntimeApiClient
         internal Func<Exception, ExceptionInfo> ExceptionConverter { get;  set; }
         internal LambdaEnvironment LambdaEnvironment { get; set; }
 
+        /// <inheritdoc/>
+        public IConsoleLoggerWriter ConsoleLogger => _consoleLoggerRedirector;
+
         /// <summary>
         /// Create a new RuntimeApiClient
         /// </summary>

Libraries/src/Amazon.Lambda.RuntimeSupport/Helpers/ConsoleLoggerWriter.cs

@@ -288,12 +288,6 @@ class WrapperTextWriter : TextWriter
             private readonly TextWriter _innerWriter;
             private string _defaultLogLevel;
 
-            const string NET_RIC_LOG_LEVEL_ENVIRONMENT_VARIABLE = "AWS_LAMBDA_HANDLER_LOG_LEVEL";
-            const string NET_RIC_LOG_FORMAT_ENVIRONMENT_VARIABLE = "AWS_LAMBDA_HANDLER_LOG_FORMAT";
-
-            const string LAMBDA_LOG_LEVEL_ENVIRONMENT_VARIABLE = "AWS_LAMBDA_LOG_LEVEL";
-            const string LAMBDA_LOG_FORMAT_ENVIRONMENT_VARIABLE = "AWS_LAMBDA_LOG_FORMAT";
-
             private LogLevel _minmumLogLevel = LogLevel.Information;
 
             enum LogFormatType { Default, Unformatted, Json }
@@ -322,7 +316,7 @@ public WrapperTextWriter(TextWriter innerWriter, string defaultLogLevel)
                 _innerWriter = innerWriter;
                 _defaultLogLevel = defaultLogLevel;
 
-                var envLogLevel = GetEnviromentVariable(NET_RIC_LOG_LEVEL_ENVIRONMENT_VARIABLE, LAMBDA_LOG_LEVEL_ENVIRONMENT_VARIABLE);
+                var envLogLevel = GetEnvironmentVariable(Constants.NET_RIC_LOG_LEVEL_ENVIRONMENT_VARIABLE, Constants.LAMBDA_LOG_LEVEL_ENVIRONMENT_VARIABLE);
                 if (!string.IsNullOrEmpty(envLogLevel))
                 {
                     // Map Lambda's fatal logging level to the .NET RIC critical
@@ -340,7 +334,7 @@ public WrapperTextWriter(TextWriter innerWriter, string defaultLogLevel)
                     }
                 }
 
-                var envLogFormat = GetEnviromentVariable(NET_RIC_LOG_FORMAT_ENVIRONMENT_VARIABLE, LAMBDA_LOG_FORMAT_ENVIRONMENT_VARIABLE);
+                var envLogFormat = GetEnvironmentVariable(Constants.NET_RIC_LOG_FORMAT_ENVIRONMENT_VARIABLE, Constants.LAMBDA_LOG_FORMAT_ENVIRONMENT_VARIABLE);
                 if (!string.IsNullOrEmpty(envLogFormat))
                 {
                     if (Enum.TryParse<LogFormatType>(envLogFormat, true, out var result))
@@ -359,7 +353,7 @@ public WrapperTextWriter(TextWriter innerWriter, string defaultLogLevel)
                 }
             }
 
-            private string GetEnviromentVariable(string envName, string fallbackEnvName)
+            private string GetEnvironmentVariable(string envName, string fallbackEnvName)
             {
                 var value = Environment.GetEnvironmentVariable(envName);
                 if(string.IsNullOrEmpty(value) && fallbackEnvName != null)

Libraries/src/Amazon.Lambda.RuntimeSupport/Helpers/FileDescriptorLogStream.cs

@@ -19,6 +19,7 @@
 using System.Text;
 using Microsoft.Win32.SafeHandles;
 using System.Collections.Concurrent;
+using Amazon.Lambda.RuntimeSupport.Bootstrap;
 
 namespace Amazon.Lambda.RuntimeSupport.Helpers
 {
@@ -33,7 +34,8 @@ public static class FileDescriptorLogFactory
         // max cloudwatch log event size, 256k - 26 bytes of overhead.
         internal const int MaxCloudWatchLogEventSize = 256 * 1024 - 26;
         internal const int LambdaTelemetryLogHeaderLength = 16;
-        internal const uint LambdaTelemetryLogHeaderFrameType = 0xa55a0003;
+        internal const uint LambdaTelemetryLogHeaderFrameTypeText = 0xa55a0003;
+        internal const uint LambdaTelemetryLogHeaderFrameTypeJson = 0xa55a0002;
         internal static readonly DateTimeOffset UnixEpoch = new DateTimeOffset(1970, 1, 1, 0, 0, 0, TimeSpan.Zero);
 
         /// <summary>
@@ -84,12 +86,19 @@ private class FileDescriptorLogStream : Stream
         {
             private readonly Stream _fileDescriptorStream;
             private readonly byte[] _frameTypeBytes;
+            private readonly uint _frameType;
 
             public FileDescriptorLogStream(Stream logStream)
             {
+                var logFormat = Environment.GetEnvironmentVariable(Constants.LAMBDA_LOG_FORMAT_ENVIRONMENT_VARIABLE);
+                _frameType = string.Equals(logFormat, Constants.LAMBDA_LOG_FORMAT_JSON, StringComparison.InvariantCultureIgnoreCase) 
+                                ? LambdaTelemetryLogHeaderFrameTypeJson : LambdaTelemetryLogHeaderFrameTypeText;
+
+                InternalLogger.GetDefaultLogger().LogDebug("FileDescriptorLogStream FrameType: " + _frameType);
+
                 _fileDescriptorStream = logStream;
 
-                _frameTypeBytes = BitConverter.GetBytes(LambdaTelemetryLogHeaderFrameType);
+                _frameTypeBytes = BitConverter.GetBytes(_frameType);
                 if (BitConverter.IsLittleEndian)
                 {
                     Array.Reverse(_frameTypeBytes);

Libraries/test/Amazon.Lambda.RuntimeSupport.Tests/Amazon.Lambda.RuntimeSupport.UnitTests/TestHelpers/TestRuntimeApiClient.cs

@@ -12,6 +12,7 @@
  * express or implied. See the License for the specific language governing
  * permissions and limitations under the License.
  */
+using Amazon.Lambda.RuntimeSupport.Helpers;
 using Amazon.Lambda.RuntimeSupport.UnitTests.TestHelpers;
 using System;
 using System.Collections.Generic;
@@ -28,6 +29,8 @@ internal class TestRuntimeApiClient : IRuntimeApiClient
         private IEnvironmentVariables _environmentVariables;
         private Dictionary<string, IEnumerable<string>> _headers;
 
+        public IConsoleLoggerWriter ConsoleLogger { get; } = new LogLevelLoggerWriter();
+
         public TestRuntimeApiClient(IEnvironmentVariables environmentVariables, Dictionary<string, IEnumerable<string>> headers)
         {
             _environmentVariables = environmentVariables;