[sdk+hosting] Move AddOpenTelemetry & OpenTelemetryBuilder into Hosting package (#4174)

* Move AddOpenTelemetry & OpenTelemetryBuilder into Hosting package.

* Added Azure Functions warning.

* Test fixes.

* Test fixes.

* Patch CHANGELOGs.

* Hosting README updates.

* Comment tweak.

* Clean up.

* Test cleanup.

* MD lint.

* Test fixes.

Author: CodeBlanch

docs/trace/getting-started-aspnetcore/Program.cs

@@ -15,7 +15,6 @@
 // </copyright>
 
 using System.Diagnostics;
-using OpenTelemetry;
 using OpenTelemetry.Resources;
 using OpenTelemetry.Trace;
 
@@ -27,8 +26,7 @@
         .AddService(serviceName: "OTel.NET Getting Started"))
     .WithTracing(builder => builder
         .AddAspNetCoreInstrumentation()
-        .AddConsoleExporter())
-    .StartWithHost();
+        .AddConsoleExporter());
 
 var app = appBuilder.Build();
 

examples/AspNetCore/Program.cs

@@ -15,7 +15,6 @@
 // </copyright>
 
 using Examples.AspNetCore;
-using OpenTelemetry;
 using OpenTelemetry.Exporter;
 using OpenTelemetry.Instrumentation.AspNetCore;
 using OpenTelemetry.Logs;
@@ -45,7 +44,7 @@
 appBuilder.Services.AddSingleton<Instrumentation>();
 
 // Configure OpenTelemetry tracing & metrics with auto-start using the
-// StartWithHost extension from OpenTelemetry.Extensions.Hosting.
+// AddOpenTelemetry extension from OpenTelemetry.Extensions.Hosting.
 appBuilder.Services.AddOpenTelemetry()
     .ConfigureResource(configureResource)
     .WithTracing(builder =>
@@ -127,8 +126,7 @@
                 builder.AddConsoleExporter();
                 break;
         }
-    })
-    .StartWithHost();
+    });
 
 // Clear default logging providers used by WebApplication host.
 appBuilder.Logging.ClearProviders();

examples/GrpcService/Startup.cs

@@ -14,7 +14,6 @@
 // limitations under the License.
 // </copyright>
 
-using OpenTelemetry;
 using OpenTelemetry.Resources;
 using OpenTelemetry.Trace;
 
@@ -61,8 +60,7 @@ public void ConfigureServices(IServiceCollection services)
                             builder.AddConsoleExporter();
                             break;
                     }
-                })
-                .StartWithHost();
+                });
         }
 
         public void Configure(IApplicationBuilder app, IWebHostEnvironment env)

examples/MicroserviceExample/WebApi/Startup.cs

@@ -14,7 +14,6 @@
 // limitations under the License.
 // </copyright>
 
-using OpenTelemetry;
 using OpenTelemetry.Trace;
 using Utils.Messaging;
 
@@ -43,8 +42,7 @@ public void ConfigureServices(IServiceCollection services)
                     {
                         var zipkinHostName = Environment.GetEnvironmentVariable("ZIPKIN_HOSTNAME") ?? "localhost";
                         b.Endpoint = new Uri($"http://{zipkinHostName}:9411/api/v2/spans");
-                    }))
-                .StartWithHost();
+                    }));
         }
 
         public void Configure(IApplicationBuilder app, IWebHostEnvironment env)

examples/MicroserviceExample/WorkerService/Program.cs

@@ -14,7 +14,6 @@
 // limitations under the License.
 // </copyright>
 
-using OpenTelemetry;
 using OpenTelemetry.Trace;
 using Utils.Messaging;
 
@@ -42,8 +41,7 @@ public static IHostBuilder CreateHostBuilder(string[] args) =>
                             {
                                 var zipkinHostName = Environment.GetEnvironmentVariable("ZIPKIN_HOSTNAME") ?? "localhost";
                                 b.Endpoint = new Uri($"http://{zipkinHostName}:9411/api/v2/spans");
-                            }))
-                        .StartWithHost();
+                            }));
                 });
     }
 }

src/OpenTelemetry.Exporter.Jaeger/README.md

@@ -98,8 +98,7 @@ services.AddOpenTelemetry()
                 client.DefaultRequestHeaders.Add("X-MyCustomHeader", "value");
                 return client;
             };
-        }))
-    .StartWithHost();
+        }));
 ```
 
 For users using

src/OpenTelemetry.Exporter.OpenTelemetryProtocol/README.md

@@ -135,8 +135,7 @@ services.AddOpenTelemetry()
                 client.DefaultRequestHeaders.Add("X-MyCustomHeader", "value");
                 return client;
             };
-        }))
-    .StartWithHost();
+        }));
 ```
 
 For users using

src/OpenTelemetry.Exporter.Prometheus.AspNetCore/README.md

@@ -28,8 +28,7 @@ dotnet add package --prerelease OpenTelemetry.Exporter.Prometheus.AspNetCore
     ```csharp
     services.AddOpenTelemetry()
         .WithMetrics(builder => builder
-            .AddPrometheusExporter())
-        .StartWithHost();
+            .AddPrometheusExporter());
     ```
 
 * Or configure directly:

src/OpenTelemetry.Exporter.Zipkin/README.md

@@ -87,8 +87,7 @@ services.AddOpenTelemetry()
             HttpClient client = new HttpClient();
             client.DefaultRequestHeaders.Add("X-MyCustomHeader", "value");
             return client;
-        }))
-    .StartWithHost();
+        }));
 ```
 
 For users using

src/OpenTelemetry.Extensions.Hosting/.publicApi/netstandard2.0/PublicAPI.Shipped.txt

@@ -0,0 +1 @@
+#nullable enable