Add otelcol docker to otlp example (#1073)

* Add OTel Collector docker to OTLP example

Adding a configuration and instructions on how to run the OpenTelemetry Collector to receive the spans generated using the OTLP exporter.

* Correct example instructions

* Separate Unix and Windows instructions

* Move collector config file to its own folder

Co-authored-by: Cijo Thomas <cithomas@microsoft.com>

examples/Console/TestOtlpExporter.cs

@@ -28,6 +28,30 @@ namespace Examples.Console
 
         private static object RunWithActivitySource(string endpoint)
         {
+            /*
+             * Setup an OpenTelemetry Collector to run on local docker.
+             *
+             * Open a terminal window at the examples/Console/ directory and
+             * launch the OpenTelemetry Collector with an OTLP receiver, by running:
+             *
+             *  - On Unix based systems use:
+             *     docker run --rm -it -p 55680:55680 -v $(pwd):/cfg otel/opentelemetry-collector:0.7.0 --config=/cfg/otlp-collector-example/config.yaml
+             *
+             *  - On Windows use:
+             *     docker run --rm -it -p 55680:55680 -v "%cd%":/cfg otel/opentelemetry-collector:0.7.0 --config=/cfg/otlp-collector-example/config.yaml
+             *
+             * On another terminal window at the examples/Console/ directory and
+             * launch the OTLP example by running:
+             *
+             *     dotnet run -p Examples.Console.csproj otlp
+             *
+             * The OpenTelemetry Collector will output all received spans to the stdout of its terminal until
+             * it is stopped via CTRL+C.
+             *
+             * For more information about the OpenTelemetry Collector go to https://github.com/open-telemetry/opentelemetry-collector
+             *
+             */
+
             // Enable OpenTelemetry for the sources "Samples.SampleServer" and "Samples.SampleClient"
             // and use OTLP exporter.
             using var openTelemetry = Sdk.CreateTracerProviderBuilder()
@@ -42,7 +66,7 @@ namespace Examples.Console
                 sample.Start();
 
                 System.Console.WriteLine("Traces are being created and exported" +
-                    "to OTLP in the background." +
+                    "to OTLP in the background. " +
                     "Press ENTER to stop.");
                 System.Console.ReadLine();
             }

examples/Console/TestZipkinExporter.cs

@@ -47,7 +47,7 @@ namespace Examples.Console
                 sample.Start();
 
                 System.Console.WriteLine("Traces are being created and exported" +
-                    "to Zipkin in the background. Use Zipkin to view them." +
+                    "to Zipkin in the background. Use Zipkin to view them. " +
                     "Press ENTER to stop.");
                 System.Console.ReadLine();
             }

examples/Console/otlp-collector-example/config.yaml

@@ -0,0 +1,20 @@
+# This is a configuration file for the OpenTelemetry Collector intended to be
+# used in conjunction with the OTLP Exporter example (see ../TestOtlpExporter.cs)
+#
+# For more information about the OpenTelemetry Collector see:
+#   https://github.com/open-telemetry/opentelemetry-collector
+#
+receivers:
+  otlp:
+    protocols:
+      grpc:
+
+exporters:
+  logging:
+    loglevel: debug
+
+service:
+  pipelines:
+    traces:
+      receivers: [otlp]
+      exporters: [logging]