Add support for Lambda log level

Author: hjgraca

libraries/src/AWS.Lambda.Powertools.Common/Core/Constants.cs

@@ -54,6 +54,11 @@ internal static class Constants
     ///     Constant for POWERTOOLS_LOG_LEVEL environment variable
     /// </summary>
     internal const string LogLevelNameEnv = "POWERTOOLS_LOG_LEVEL";
+    
+    /// <summary>
+    ///     Constant for POWERTOOLS_LOG_LEVEL environment variable
+    /// </summary>
+    internal const string AwsLogLevelNameEnv = "AWS_LAMBDA_LOG_LEVEL";
 
     /// <summary>
     ///     Constant for POWERTOOLS_LOGGER_SAMPLE_RATE environment variable

libraries/src/AWS.Lambda.Powertools.Common/Core/PowertoolsConfigurations.cs

@@ -152,7 +152,7 @@ public bool GetEnvironmentVariableOrDefault(string variable, bool defaultValue)
     /// </summary>
     /// <value>The log level.</value>
     public string LogLevel =>
-        GetEnvironmentVariable(Constants.LogLevelNameEnv);
+        GetEnvironmentVariableOrDefault(Constants.AwsLogLevelNameEnv, GetEnvironmentVariable(Constants.LogLevelNameEnv));
 
     /// <summary>
     ///     Gets the logger sample rate.

libraries/tests/AWS.Lambda.Powertools.Logging.Tests/PowertoolsLoggerTest.cs

@@ -1,12 +1,12 @@
 /*
  * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * 
+ *
  * Licensed under the Apache License, Version 2.0 (the "License").
  * You may not use this file except in compliance with the License.
  * A copy of the License is located at
- * 
+ *
  *  http://aws.amazon.com/apache2.0
- * 
+ *
  * or in the "license" file accompanying this file. This file is distributed
  * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
  * express or implied. See the License for the specific language governing
@@ -21,8 +21,11 @@
 using System.Text;
 using AWS.Lambda.Powertools.Common;
 using AWS.Lambda.Powertools.Logging.Internal;
+using AWS.Lambda.Powertools.Logging.Tests.Utilities;
 using Microsoft.Extensions.Logging;
 using NSubstitute;
+using NSubstitute.Extensions;
+using NSubstitute.ReceivedExtensions;
 using Xunit;
 
 namespace AWS.Lambda.Powertools.Logging.Tests
@@ -34,7 +37,7 @@ public PowertoolsLoggerTest()
         {
             Logger.UseDefaultFormatter();
         }
-        
+
         private static void Log_WhenMinimumLevelIsBelowLogLevel_Logs(LogLevel logLevel, LogLevel minimumLevel)
         {
             // Arrange
@@ -1219,7 +1222,7 @@ public void Log_Set_Execution_Environment_Context()
                 $"{Constants.FeatureContextIdentifier}/Logger/{assemblyVersion}");
             env.Received(1).GetEnvironmentVariable("AWS_EXECUTION_ENV");
         }
-        
+
         [Fact]
         public void Log_Should_Serialize_DateOnly()
         {
@@ -1260,7 +1263,7 @@ public void Log_Should_Serialize_DateOnly()
                 )
             );
         }
-        
+
         [Fact]
         public void Log_Should_Serialize_TimeOnly()
         {
@@ -1301,5 +1304,74 @@ public void Log_Should_Serialize_TimeOnly()
                 )
             );
         }
+
+        [Theory]
+        [InlineData(true, LogLevel.Warning)]
+        [InlineData(false, LogLevel.Critical)]
+        public void Log_Should_Use_Lambda_Log_Level_When_Enabled(bool willLog, LogLevel logLevel)
+        {
+            // Arrange
+            var loggerName = Guid.NewGuid().ToString();
+
+            var environment = Substitute.For<IPowertoolsEnvironment>();
+            environment.GetEnvironmentVariable("POWERTOOLS_LOG_LEVEL").Returns("Error");
+            environment.GetEnvironmentVariable("AWS_LAMBDA_LOG_LEVEL").Returns(logLevel.ToString());
+
+            var systemWrapper = new SystemWrapperMock(environment);
+            var configuration = new PowertoolsConfigurations(systemWrapper);
+
+            var logger = new PowertoolsLogger(loggerName, configuration, systemWrapper, () =>
+                new LoggerConfiguration
+                {
+                    LoggerOutputCase = LoggerOutputCase.CamelCase
+                });
+
+            var message = new
+            {
+                PropOne = "Value 1",
+                PropTwo = "Value 2",
+                Time = new TimeOnly(12, 0, 0)
+            };
+
+            logger.LogWarning(message);
+            
+            Assert.True(logger.IsEnabled(logLevel));
+            Assert.Equal(logLevel.ToString(), configuration.LogLevel);
+            Assert.Equal(willLog, systemWrapper.LogMethodCalled);
+        }
+
+        [Theory]
+        [InlineData(true, LogLevel.Warning)]
+        [InlineData(false, LogLevel.Critical)]
+        public void Log_Should_Use_Powertools_Log_Level_When_Lambda_Log_Level_Unavailable(bool willLog, LogLevel logLevel)
+        {
+            // Arrange
+            var loggerName = Guid.NewGuid().ToString();
+            var environment = Substitute.For<IPowertoolsEnvironment>();
+            environment.GetEnvironmentVariable("POWERTOOLS_LOG_LEVEL").Returns(logLevel.ToString());
+
+            var systemWrapper = new SystemWrapperMock(environment);
+            var configuration = new PowertoolsConfigurations(systemWrapper);
+
+            var logger = new PowertoolsLogger(loggerName, configuration, systemWrapper, () =>
+                new LoggerConfiguration
+                {
+                    LoggerOutputCase = LoggerOutputCase.CamelCase
+                });
+
+            var message = new
+            {
+                PropOne = "Value 1",
+                PropTwo = "Value 2",
+                Time = new TimeOnly(12, 0, 0)
+            };
+
+            logger.LogWarning(message);
+
+            // Assert
+            Assert.True(logger.IsEnabled(logLevel));
+            Assert.Equal(logLevel.ToString(), configuration.LogLevel);
+            Assert.Equal(willLog, systemWrapper.LogMethodCalled);
+        }
     }
 }

libraries/tests/AWS.Lambda.Powertools.Logging.Tests/Utilities/SystemWrapperMock.cs

@@ -0,0 +1,58 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+using AWS.Lambda.Powertools.Common;
+
+namespace AWS.Lambda.Powertools.Logging.Tests.Utilities;
+
+public class SystemWrapperMock : ISystemWrapper
+{
+    private readonly IPowertoolsEnvironment _powertoolsEnvironment;
+    public bool LogMethodCalled { get; private set; }
+
+    public SystemWrapperMock(IPowertoolsEnvironment powertoolsEnvironment)
+    {
+        _powertoolsEnvironment = powertoolsEnvironment;
+    }
+
+    public string GetEnvironmentVariable(string variable)
+    {
+        return _powertoolsEnvironment.GetEnvironmentVariable(variable);
+    }
+
+    public void Log(string value)
+    {
+        LogMethodCalled = true;
+    }
+    
+    public void LogLine(string value)
+    {
+        LogMethodCalled = true;
+    }
+
+    public double GetRandom()
+    {
+        throw new System.NotImplementedException();
+    }
+
+    public void SetEnvironmentVariable(string variable, string value)
+    {
+        throw new System.NotImplementedException();
+    }
+
+    public void SetExecutionEnvironment<T>(T type)
+    {
+    }
+}