Better tests and docs

Author: cyrille-leclerc

maven-extension/src/main/java/io/opentelemetry/maven/OpenTelemetrySdkService.java

@@ -5,6 +5,7 @@
 
 package io.opentelemetry.maven;
 
+import com.google.common.annotations.VisibleForTesting;
 import io.opentelemetry.api.OpenTelemetry;
 import io.opentelemetry.api.trace.Tracer;
 import io.opentelemetry.context.propagation.ContextPropagators;
@@ -40,7 +41,7 @@ public final class OpenTelemetrySdkService implements Closeable {
 
   private final OpenTelemetrySdk openTelemetrySdk;
 
-  private final Resource resource;
+  @VisibleForTesting final Resource resource;
 
   private final ConfigProperties configProperties;
 
@@ -67,10 +68,10 @@ public OpenTelemetrySdkService() {
     this.configProperties =
         Optional.ofNullable(AutoConfigureUtil.getConfig(autoConfiguredOpenTelemetrySdk))
             .orElseGet(() -> DefaultConfigProperties.createFromMap(Collections.emptyMap()));
-    this.resource =
-        Optional.ofNullable(AutoConfigureUtil2.getResource(autoConfiguredOpenTelemetrySdk))
-            .orElseGet(Resource::getDefault);
 
+    this.resource = AutoConfigureUtil2.getResource(autoConfiguredOpenTelemetrySdk);
+    // Display resource attributes in debug logs for troubleshooting when traces are not found in
+    // the observability backend, helping understand `service.name`, `service.namespace`, etc.
     logger.debug("OpenTelemetry: OpenTelemetrySdkService initialized, resource:{}", resource);
 
     this.mojosInstrumentationEnabled =
@@ -141,10 +142,6 @@ public Tracer getTracer() {
     return this.tracer;
   }
 
-  public Resource getResource() {
-    return resource;
-  }
-
   public ConfigProperties getConfigProperties() {
     return configProperties;
   }

maven-extension/src/test/java/io/opentelemetry/maven/OpenTelemetrySdkServiceTest.java

@@ -10,6 +10,7 @@
 
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
 import io.opentelemetry.sdk.resources.Resource;
+import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.Test;
 
 /**
@@ -26,7 +27,7 @@ public void testDefaultConfiguration() {
     System.clearProperty("otel.resource.attributes");
     try (OpenTelemetrySdkService openTelemetrySdkService = new OpenTelemetrySdkService()) {
 
-      Resource resource = openTelemetrySdkService.getResource();
+      Resource resource = openTelemetrySdkService.resource;
       assertThat(resource.getAttribute(stringKey("service.name"))).isEqualTo("maven");
 
       ConfigProperties configProperties = openTelemetrySdkService.getConfigProperties();
@@ -45,7 +46,7 @@ public void testOverwrittenResourceAttributes() {
 
     try (OpenTelemetrySdkService openTelemetrySdkService = new OpenTelemetrySdkService()) {
 
-      Resource resource = openTelemetrySdkService.getResource();
+      Resource resource = openTelemetrySdkService.resource;
       assertThat(resource.getAttribute(stringKey("service.name"))).isEqualTo("my-maven");
       assertThat(resource.getAttribute(stringKey("key1"))).isEqualTo("val1");
       assertThat(resource.getAttribute(stringKey("key2"))).isEqualTo("val2");
@@ -122,4 +123,14 @@ public void testOverwrittenExporterConfiguration_3() {
       System.clearProperty("otel.exporter.otlp.traces.protocol");
     }
   }
+
+  @AfterAll
+  static void afterAll() {
+    System.clearProperty("otel.exporter.otlp.endpoint");
+    System.clearProperty("otel.exporter.otlp.traces.endpoint");
+    System.clearProperty("otel.exporter.otlp.traces.protocol");
+    System.clearProperty("otel.resource.attributes");
+    System.clearProperty("otel.service.name");
+    System.clearProperty("otel.traces.exporter");
+  }
 }