[Sdk] Added options for disabling signals

build/Common.props

@@ -31,6 +31,7 @@
     <MicrosoftAspNetCoreHttpFeaturesPkgVer>[2.1.1,6.0)</MicrosoftAspNetCoreHttpFeaturesPkgVer>
     <MicrosoftCodeAnalysisAnalyzersPkgVer>[3.3.3]</MicrosoftCodeAnalysisAnalyzersPkgVer>
     <MicrosoftCodeCoveragePkgVer>[17.3.0]</MicrosoftCodeCoveragePkgVer>
+    <MicrosoftExtensionsConfigurationEnvironmentVariablesPkgVer>[3.1.0,)</MicrosoftExtensionsConfigurationEnvironmentVariablesPkgVer>
     <MicrosoftExtensionsHostingAbstractionsPkgVer>[2.1.0,)</MicrosoftExtensionsHostingAbstractionsPkgVer>
     <MicrosoftExtensionsLoggingPkgVer>[3.1.0,)</MicrosoftExtensionsLoggingPkgVer>
     <MicrosoftExtensionsLoggingConfigurationPkgVer>[3.1.0,)</MicrosoftExtensionsLoggingConfigurationPkgVer>

src/OpenTelemetry/OpenTelemetry.csproj

@@ -19,6 +19,7 @@
     <PackageReference Include="System.Reflection.Emit.Lightweight" Version="$(SystemReflectionEmitLightweightPkgVer)" Condition="'$(TargetFramework)' != 'net6.0'" />
     <PackageReference Include="Microsoft.Extensions.Logging" Version="$(MicrosoftExtensionsLoggingPkgVer)" />
     <PackageReference Include="Microsoft.Extensions.Logging.Configuration" Version="$(MicrosoftExtensionsLoggingConfigurationPkgVer)" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" Version="$(MicrosoftExtensionsConfigurationEnvironmentVariablesPkgVer)" />
   </ItemGroup>
 
   <ItemGroup>

src/OpenTelemetry/SdkOptions.cs

@@ -0,0 +1,68 @@
+// <copyright file="SdkOptions.cs" company="OpenTelemetry Authors">
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License 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.
+// </copyright>
+
+#nullable enable
+
+using System;
+using System.Diagnostics;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Options;
+
+namespace OpenTelemetry
+{
+    public sealed class SdkOptions
+    {
+        private static Action<SdkOptions>? globalConfigureCallbacks;
+
+        public bool TracingEnabled { get; set; } = true;
+
+        public bool MetricsEnabled { get; set; } = true;
+
+        public bool LoggingEnabled { get; set; } = true;
+
+        public static void RegisterConfigureCallback(Action<SdkOptions> configure)
+        {
+            globalConfigureCallbacks += configure ?? throw new ArgumentNullException(nameof(configure));
+        }
+
+        internal sealed class ConfigureSdkOptions : IConfigureOptions<SdkOptions>
+        {
+            private readonly IConfiguration configuration;
+
+            public ConfigureSdkOptions(IConfiguration configuration)
+            {
+                Debug.Assert(configuration != null, "configuration was null");
+
+                this.configuration = configuration;
+            }
+
+            public void Configure(SdkOptions options)
+            {
+                Debug.Assert(options != null, "options was null");
+
+                var globalDisableFlagValue = this.configuration.GetValue("OTEL_SDK_DISABLED", false);
+                if (globalDisableFlagValue)
+                {
+                    options.TracingEnabled = false;
+                    options.MetricsEnabled = false;
+                    options.LoggingEnabled = false;
+                }
+
+                globalConfigureCallbacks?.Invoke(options);
+            }
+        }
+    }
+}

src/OpenTelemetry/Trace/Builder/TracerProviderBuilderBase.cs

@@ -18,6 +18,7 @@
 
 using System;
 using System.Diagnostics;
+using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Options;
@@ -51,8 +52,15 @@ internal TracerProviderBuilderBase(IServiceCollection services)
         {
             Guard.ThrowIfNull(services);
 
-            services.AddOptions();
-            services.TryAddSingleton<TracerProvider>(sp => new TracerProviderSdk(sp, ownsServiceProvider: false));
+            RegisterSharedServices(services);
+
+            services.TryAddSingleton<TracerProvider>(sp =>
+            {
+                var sdkOptions = sp.GetRequiredService<IOptions<SdkOptions>>().Value;
+                return !sdkOptions.TracingEnabled
+                    ? new NoopTracerProvider()
+                    : new TracerProviderSdk(sp, ownsServiceProvider: false);
+            });
 
             this.services = services;
             this.ownsServices = false;
@@ -64,7 +72,7 @@ protected TracerProviderBuilderBase()
         {
             var services = new ServiceCollection();
 
-            services.AddOptions();
+            RegisterSharedServices(services);
 
             this.services = services;
             this.ownsServices = true;
@@ -264,7 +272,24 @@ protected TracerProvider Build()
 
             var serviceProvider = services.BuildServiceProvider();
 
-            return new TracerProviderSdk(serviceProvider, ownsServiceProvider: true);
+            var sdkOptions = serviceProvider.GetRequiredService<IOptions<SdkOptions>>().Value;
+            if (!sdkOptions.TracingEnabled)
+            {
+                serviceProvider.Dispose();
+
+                return new NoopTracerProvider();
+            }
+            else
+            {
+                return new TracerProviderSdk(serviceProvider, ownsServiceProvider: true);
+            }
+        }
+
+        private static void RegisterSharedServices(IServiceCollection services)
+        {
+            services.AddOptions();
+            services.TryAddSingleton<IConfiguration>(sp => new ConfigurationBuilder().AddEnvironmentVariables().Build());
+            services.TryAddSingleton<IConfigureOptions<SdkOptions>, SdkOptions.ConfigureSdkOptions>();
         }
 
         private static BaseProcessor<Activity> BuildExportProcessor(
@@ -332,10 +357,7 @@ private void TryAddSingleton<T>()
         {
             var services = this.services;
 
-            if (services != null)
-            {
-                services.TryAddSingleton<T>();
-            }
+            services?.TryAddSingleton<T>();
         }
     }
 }

src/OpenTelemetry/Trace/NoopTracerProvider.cs

@@ -0,0 +1,24 @@
+// <copyright file="NoopTracerProvider.cs" company="OpenTelemetry Authors">
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License 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.
+// </copyright>
+
+#nullable enable
+
+namespace OpenTelemetry.Trace
+{
+    internal sealed class NoopTracerProvider : TracerProvider
+    {
+    }
+}