Add troubleshooting readme and traces example

examples/troubleshooting/README.md

@@ -0,0 +1,41 @@
+# Troubleshooting EDOT agent setups
+
+This directory holds code examples for testing aspects of running applications
+with the EDOT Java agent
+
+# Compilation
+
+Currently the examples are just standalone code. The 
+dependencies are the opentelemetry jars, so putting any
+of the code examples into a project and adding these three
+dependencies will allow for easy compilation
+
+- io.opentelemetry:opentelemetry-api
+- io.opentelemetry:opentelemetry-sdk
+- io.opentelemetry:opentelemetry-exporter-otlp
+
+(Manual compilation would require the jars and their dependencies downloaded, and then javac -cp <list of jars> path-to-java-file.)
+
+# Traces
+
+The TestOtelSdkTrace class is a standalone class that creates
+a span (named `test span`) in a service that you name. It takes
+three arguments
+1. The name of the service you want to have displayed in the APM UI
+2. The endpoint to send traces to, normally the Elastic APM server or the OpenTelemetry collector.
+   The url would typically look like `http://localhost:4318/v1/traces` or `https://somewhere:443/v1/traces` 
+   but if `/v1/traces` is missing from the argument, it is added to the endpoint 
+3. The secret token or apikey in the format secret:<token> or apikey:<apikey>. 
+   If the argument doesn't start with neither `secret:` nor `apikey:`, then the full argument is assumed to be a secret token
+
+After running the class, you should see the trace in the APM UI, eg with service name set to `test1` and
+correct endpoint and token, you should see something similar to 
+![this](images\test-trace.png)
+
+# Metrics
+
+To do
+
+# Logs
+
+To do

examples/troubleshooting/src/main/java/elastic/troubleshooting/TestOtelSdkTrace.java

@@ -0,0 +1,62 @@
+package elastic.troubleshooting;
+
+import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.api.trace.Tracer;
+import io.opentelemetry.exporter.otlp.http.trace.OtlpHttpSpanExporter;
+import io.opentelemetry.sdk.OpenTelemetrySdk;
+import io.opentelemetry.sdk.resources.Resource;
+import io.opentelemetry.sdk.trace.SdkTracerProvider;
+import io.opentelemetry.sdk.trace.export.BatchSpanProcessor;
+
+public class TestOtelSdkTrace {
+
+  public static void main(String[] args) throws Exception {
+    String servicename = args[0];
+    String endpoint = args[1];
+    String secretOrApikey = args[2];
+    if (!endpoint.endsWith("/v1/traces")) {
+      if (endpoint.endsWith("/")) {
+        endpoint = endpoint + "v1/traces";
+      } else {
+        endpoint = endpoint + "/v1/traces";
+      }
+    }
+    boolean isSecret = true;
+    if (secretOrApikey.startsWith("secret:")) {
+      secretOrApikey = secretOrApikey.substring(7);
+    } else if (secretOrApikey.startsWith("apikey:")) {
+      secretOrApikey = secretOrApikey.substring(7);
+      isSecret = false;
+    }
+
+    System.out.println("Starting test ... initializing OpenTelemetry");
+
+    Resource resource = Resource.getDefault().toBuilder().put("service.name", servicename).build();
+
+    OtlpHttpSpanExporter spanExporter = OtlpHttpSpanExporter.builder().setEndpoint(endpoint)
+        .addHeader("Authorization", (isSecret ? "Bearer " : "ApiKey ") + secretOrApikey).build();
+
+    SdkTracerProvider tracerProvider = SdkTracerProvider.builder()
+        .addSpanProcessor(BatchSpanProcessor.builder(spanExporter).build()).setResource(resource)
+        .build();
+
+    OpenTelemetrySdk openTelemetry = OpenTelemetrySdk.builder().setTracerProvider(tracerProvider)
+        .build();
+
+    System.out.println("Starting test ... creating a span");
+
+    Tracer tracer = openTelemetry.getTracer("TestOtelSdkTrace");
+    Span span = tracer.spanBuilder("test span").startSpan();
+    try {
+      System.out.println("Starting test ... ending the span");
+    } finally {
+      span.end();
+    }
+    openTelemetry.shutdown().whenComplete(() -> {
+      System.out.println("Ending test ... shutdown OpenTelemetry");
+    });
+
+    Thread.sleep(60_000L);
+    System.out.println("Ending test ... terminating the JVM");
+  }
+}