Use single instance of WebhostMetricsLogger

Author: yojagad

src/WebJobs.Script.WebHost/DependencyInjection/DependencyValidator/DependencyValidator.cs

@@ -29,7 +29,7 @@ private static ExpectedDependencyBuilder CreateExpectedDependencies()
             expected.ExpectNone<IEventGenerator>();
 
             expected.Expect<ILoggerFactory, ScriptLoggerFactory>();
-            expected.Expect<IMetricsLogger, WebHostMetricsLogger>();
+            expected.ExpectInstance<IMetricsLogger, WebHostMetricsLogger>();
 
             expected.Expect<IWebJobsExceptionHandler, WebScriptHostExceptionHandler>();
 

src/WebJobs.Script.WebHost/WebHostServiceCollectionExtensions.cs

@@ -109,9 +109,6 @@ public static void AddWebJobsScriptHost(this IServiceCollection services, IConfi
             services.AddTransient<VirtualFileSystem>();
             services.AddTransient<VirtualFileSystemMiddleware>();
 
-            // Logging and diagnostics
-            services.AddSingleton<IMetricsLogger, WebHostMetricsLogger>();
-
             // Secret management
             services.TryAddSingleton<ISecretManagerProvider, DefaultSecretManagerProvider>();
 

src/WebJobs.Script.WebHost/WebScriptHostBuilderExtension.cs

@@ -91,7 +91,13 @@ public static IHostBuilder AddWebScriptHost(this IHostBuilder builder, IServiceP
                     }
 
                     // Logging and diagnostics
-                    services.AddSingleton<IMetricsLogger, WebHostMetricsLogger>();
+                    // Get WebHostMetricsLogger registered at webhost
+                    IMetricsLogger metricsLogger = rootServiceProvider.GetService<IMetricsLogger>();
+                    if (metricsLogger != null)
+                    {
+                        services.AddSingleton(metricsLogger);
+                    }
+
                     services.AddSingleton<IEventCollectorProvider, FunctionInstanceLogCollectorProvider>();
 
                     // Hosted services

src/WebJobs.Script/ScriptHostBuilderExtensions.cs

@@ -133,7 +133,10 @@ public static IHostBuilder AddScriptHostCore(this IHostBuilder builder, ScriptAp
                 services.AddSingleton<ITypeLocator, ScriptTypeLocator>();
                 services.AddSingleton<ScriptSettingsManager>();
                 services.AddTransient<IExtensionsManager, ExtensionsManager>();
+
+                // Fallback option if webhost is not present.
                 services.TryAddSingleton<IMetricsLogger, MetricsLogger>();
+
                 services.TryAddSingleton<IScriptJobHostEnvironment, ConsoleScriptJobHostEnvironment>();
                 services.AddTransient<IExtensionBundleContentProvider, ExtensionBundleContentProvider>();
 

test/WebJobs.Script.Tests/Description/DotNet/DotNetFunctionInvokerTests.cs

@@ -434,8 +434,6 @@ private RunDependencies CreateDependencies(Action<IServiceCollection> configureS
             compilationServiceFactory.Setup(f => f.CreateService(DotNetScriptTypes.CSharp, It.IsAny<IFunctionMetadataResolver>()))
                 .Returns(compilationService.Object);
 
-            var metricsLogger = new MetricsLogger();
-
             var hostBuilder = new HostBuilder()
                 .ConfigureDefaultTestWebScriptHost(o =>
                 {
@@ -461,7 +459,7 @@ private RunDependencies CreateDependencies(Action<IServiceCollection> configureS
                 CompilationServiceFactory = compilationServiceFactory,
                 LoggerProvider = loggerProvider,
                 LoggerFactory = loggerFactory,
-                MetricsLogger = metricsLogger
+                MetricsLogger = new TestMetricsLogger(),
             };
         }
 
@@ -495,7 +493,7 @@ private class RunDependencies
 
             public ILoggerFactory LoggerFactory { get; set; }
 
-            public MetricsLogger MetricsLogger { get; set; }
+            public IMetricsLogger MetricsLogger { get; set; }
         }
     }
 }