Feature - clear logger providers except functions extension (#134)

* Feature - clear logger providers except functions

* pr-sug: update docs w/ created project

docs/preview/guidance/use-with-dotnet-and-functions.md

@@ -23,13 +23,13 @@ Using Serilog with Azure Functions requires some guidance and we've made it a bi
 Before we get started, install our NuGet package for Azure Functions:
 
 ```
-PM > TODO @stijnmoreels
+PM > Install-Package -Name Arcus.Observability.Telemetry.AzureFunctions
 ```
 
 Once that is done, you can configure Serilog during startup as following:
 
 ```csharp
-using Arcus.TODO.@stijnmoreels;
+using Microsoft.Extensions.Logging;
 
 [assembly: FunctionsStartup(typeof(Startup))]
 namespace Arcus.Samples.AzureFunction

src/Arcus.Observability.Telemetry.AzureFunctions/Arcus.Observability.Telemetry.AzureFunctions.csproj

@@ -0,0 +1,32 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFrameworks>netstandard2.0;netcoreapp3.1</TargetFrameworks>
+    <Authors>Arcus</Authors>
+    <Company>Arcus</Company>
+    <Description>Provides capability to improve telemetry with Serilog in Azure Functions applications</Description>
+    <Copyright>Copyright (c) Arcus</Copyright>
+    <PackageLicenseUrl>https://github.com/arcus-azure/arcus.observability/blob/master/LICENSE</PackageLicenseUrl>
+    <PackageProjectUrl>https://github.com/arcus-azure/arcus.observability</PackageProjectUrl>
+    <PackageIconUrl>https://raw.githubusercontent.com/arcus-azure/arcus/master/media/arcus.png</PackageIconUrl>
+    <RepositoryUrl>https://github.com/arcus-azure/arcus.observability</RepositoryUrl>
+    <RepositoryType>Git</RepositoryType>
+    <PackageTags>Azure;Observability;Telemetry;Azure Functions</PackageTags>
+    <PackageId>Arcus.Observability.Telemetry.AzureFunctions</PackageId>
+    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
+  </PropertyGroup>
+
+  <ItemGroup Condition="'$(TargetFramework)' == 'netcoreapp3.1'">
+    <FrameworkReference Include="Microsoft.AspNetCore.App" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(TargetFramework)' != 'netcoreapp3.1'">
+    <PackageReference Include="Microsoft.Extensions.Logging" Version="2.2.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Guard.Net" Version="1.2.0" />
+  </ItemGroup>
+
+</Project>

src/Arcus.Observability.Telemetry.AzureFunctions/Extensions/ILoggerBuilderExtensions.cs

@@ -0,0 +1,39 @@
+using GuardNet;
+using Microsoft.Extensions.DependencyInjection;
+
+// ReSharper disable once CheckNamespace
+namespace Microsoft.Extensions.Logging
+{
+    /// <summary>
+    /// <see cref="ILoggingBuilder"/> extensions related to Azure Functions projects.
+    /// </summary>
+    // ReSharper disable once InconsistentNaming
+    public static class ILoggingBuilderExtensions
+    {
+        /// <summary>
+        /// Clears the <see cref="ILoggerProvider"/> registrations from the given <paramref name="loggingBuilder"/>,
+        /// except the specific Azure Functions registrations.
+        /// </summary>
+        /// <param name="loggingBuilder">The builder containing the <see cref="ILoggerProvider"/> registrations.</param>
+        public static ILoggingBuilder ClearProvidersExceptFunctionProviders(this ILoggingBuilder loggingBuilder)
+        {
+            Guard.NotNull(loggingBuilder, nameof(loggingBuilder));
+
+            // Kudos to katrash: https://stackoverflow.com/questions/45986517/remove-console-and-debug-loggers-in-asp-net-core-2-0-when-in-production-mode
+            foreach (ServiceDescriptor serviceDescriptor in loggingBuilder.Services)
+            {
+                if (serviceDescriptor.ServiceType == typeof(ILoggerProvider))
+                {
+                    if (serviceDescriptor.ImplementationType.FullName != "Microsoft.Azure.WebJobs.Script.Diagnostics.HostFileLoggerProvider"
+                        && serviceDescriptor.ImplementationType.FullName != "Microsoft.Azure.WebJobs.Script.Diagnostics.FunctionFileLoggerProvider")
+                    {
+                        loggingBuilder.Services.Remove(serviceDescriptor);
+                        break;
+                    }
+                }
+            }
+
+            return loggingBuilder;
+        }
+    }
+}

src/Arcus.Observability.Tests.Unit/Arcus.Observability.Tests.Unit.csproj

@@ -18,6 +18,7 @@
   <ItemGroup>
     <ProjectReference Include="..\Arcus.Observability.Correlation\Arcus.Observability.Correlation.csproj" />
     <ProjectReference Include="..\Arcus.Observability.Telemetry.IoT\Arcus.Observability.Telemetry.IoT.csproj" />
+    <ProjectReference Include="..\Arcus.Observability.Telemetry.AzureFunctions\Arcus.Observability.Telemetry.AzureFunctions.csproj" />
     <ProjectReference Include="..\Arcus.Observability.Telemetry.Serilog.Filters\Arcus.Observability.Telemetry.Serilog.Filters.csproj" />
     <ProjectReference Include="..\Arcus.Observability.Telemetry.Serilog.Sinks.ApplicationInsights\Arcus.Observability.Telemetry.Serilog.Sinks.ApplicationInsights.csproj" />
     <ProjectReference Include="..\Arcus.Observability.Telemetry.Serilog.Enrichers\Arcus.Observability.Telemetry.Serilog.Enrichers.csproj" />

src/Arcus.Observability.Tests.Unit/Telemetry/AzureFunctions/Fixture/FunctionFileLoggerProvider.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using Microsoft.Extensions.Logging;
+
+// ReSharper disable once CheckNamespace
+namespace Microsoft.Azure.WebJobs.Script.Diagnostics
+{
+    /// <summary>
+    /// <see cref="ILoggerProvider"/> to verify if the surrogate of the real provider doesn't get removed.
+    /// </summary>
+    public class FunctionFileLoggerProvider : ILoggerProvider
+    {
+        /// <summary>
+        /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
+        /// </summary>
+        public void Dispose()
+        {
+            throw new NotImplementedException();
+        }
+
+        /// <summary>
+        /// Creates a new <see cref="T:Microsoft.Extensions.Logging.ILogger" /> instance.
+        /// </summary>
+        /// <param name="categoryName">The category name for messages produced by the logger.</param>
+        /// <returns>The instance of <see cref="T:Microsoft.Extensions.Logging.ILogger" /> that was created.</returns>
+        public ILogger CreateLogger(string categoryName)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}

src/Arcus.Observability.Tests.Unit/Telemetry/AzureFunctions/Fixture/HostFileLoggerProvider.cs

@@ -0,0 +1,30 @@
+using System;
+using Microsoft.Extensions.Logging;
+
+// ReSharper disable once CheckNamespace
+namespace Microsoft.Azure.WebJobs.Script.Diagnostics
+{
+    /// <summary>
+    /// <see cref="ILoggerProvider"/> to verify if the surrogate of the real provider doesn't get removed.
+    /// </summary>
+    public class HostFileLoggerProvider : ILoggerProvider
+    {
+        /// <summary>
+        /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
+        /// </summary>
+        public void Dispose()
+        {
+            throw new NotImplementedException();
+        }
+
+        /// <summary>
+        /// Creates a new <see cref="T:Microsoft.Extensions.Logging.ILogger" /> instance.
+        /// </summary>
+        /// <param name="categoryName">The category name for messages produced by the logger.</param>
+        /// <returns>The instance of <see cref="T:Microsoft.Extensions.Logging.ILogger" /> that was created.</returns>
+        public ILogger CreateLogger(string categoryName)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}

src/Arcus.Observability.Tests.Unit/Telemetry/AzureFunctions/Fixture/TestLoggerProvider.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using Microsoft.Extensions.Logging;
+
+namespace Arcus.Observability.Tests.Unit.Telemetry.AzureFunctions.Fixture
+{
+    /// <summary>
+    /// <see cref="ILoggerProvider"/> implementation to verify if the provider gets removed during the <see cref="ILoggerBuilderExtensionsTests"/>.
+    /// </summary>
+    public class TestLoggerProvider : ILoggerProvider
+    {
+        /// <summary>Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.</summary>
+        public void Dispose()
+        {
+            throw new NotImplementedException();
+        }
+
+        /// <summary>
+        /// Creates a new <see cref="T:Microsoft.Extensions.Logging.ILogger" /> instance.
+        /// </summary>
+        /// <param name="categoryName">The category name for messages produced by the logger.</param>
+        /// <returns>The instance of <see cref="T:Microsoft.Extensions.Logging.ILogger" /> that was created.</returns>
+        public ILogger CreateLogger(string categoryName)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}

src/Arcus.Observability.Tests.Unit/Telemetry/AzureFunctions/ILoggerBuilderExtensionsTests.cs

@@ -0,0 +1,32 @@
+using Arcus.Observability.Tests.Unit.Telemetry.AzureFunctions.Fixture;
+using Microsoft.Azure.WebJobs.Script.Diagnostics;
+using Microsoft.Extensions.DependencyInjection;
+using Moq;
+using Microsoft.Extensions.Logging;
+using Xunit;
+
+namespace Arcus.Observability.Tests.Unit.Telemetry.AzureFunctions
+{
+    public class ILoggerBuilderExtensionsTests
+    {
+        [Fact]
+        public void ClearProvidersExceptFunctions_WithLoggerBuilderContainingProviders_RemovesNonFunctionProviders()
+        {
+            // Arrange
+            var services = new ServiceCollection();
+            services.AddSingleton<ILoggerProvider, HostFileLoggerProvider>();
+            services.AddSingleton<ILoggerProvider, FunctionFileLoggerProvider>();
+            services.AddSingleton<ILoggerProvider, TestLoggerProvider>();
+            var builder = new Mock<ILoggingBuilder>();
+            builder.Setup(b => b.Services).Returns(services);
+
+            // Act
+            builder.Object.ClearProvidersExceptFunctionProviders();
+
+            // Assert
+            Assert.NotEmpty(services);
+            Assert.Equal(2, services.Count);
+            Assert.All(services, desc => Assert.NotEqual(typeof(TestLoggerProvider), desc.ImplementationType));
+        }
+    }
+}

src/Arcus.Observability.sln

@@ -23,6 +23,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Arcus.Observability.Tests.C
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Arcus.Observability.Telemetry.IoT", "Arcus.Observability.Telemetry.IoT\Arcus.Observability.Telemetry.IoT.csproj", "{E4A6624B-C1A4-4956-9FC2-E77D6C634717}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Arcus.Observability.Telemetry.AzureFunctions", "Arcus.Observability.Telemetry.AzureFunctions\Arcus.Observability.Telemetry.AzureFunctions.csproj", "{C6C0ED5D-94B4-4CD2-B17A-E72432AC4883}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -65,6 +67,10 @@ Global
 		{E4A6624B-C1A4-4956-9FC2-E77D6C634717}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{E4A6624B-C1A4-4956-9FC2-E77D6C634717}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{E4A6624B-C1A4-4956-9FC2-E77D6C634717}.Release|Any CPU.Build.0 = Release|Any CPU
+		{C6C0ED5D-94B4-4CD2-B17A-E72432AC4883}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{C6C0ED5D-94B4-4CD2-B17A-E72432AC4883}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{C6C0ED5D-94B4-4CD2-B17A-E72432AC4883}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{C6C0ED5D-94B4-4CD2-B17A-E72432AC4883}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE