Use ConditionalResourceProvider in the Spring Boot service name provider

instrumentation/spring/spring-boot-resources/library/src/main/java/io/opentelemetry/instrumentation/spring/resources/SpringBootServiceNameGuesser.java

@@ -8,6 +8,7 @@
 import com.google.auto.service.AutoService;
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
 import io.opentelemetry.sdk.autoconfigure.spi.ResourceProvider;
+import io.opentelemetry.sdk.autoconfigure.spi.internal.ConditionalResourceProvider;
 import io.opentelemetry.sdk.resources.Resource;
 import io.opentelemetry.semconv.resource.attributes.ResourceAttributes;
 import java.io.IOException;
@@ -47,7 +48,7 @@
  * </ul>
  */
 @AutoService(ResourceProvider.class)
-public class SpringBootServiceNameGuesser implements ResourceProvider {
+public class SpringBootServiceNameGuesser implements ConditionalResourceProvider {
 
   private static final Logger logger =
       Logger.getLogger(SpringBootServiceNameGuesser.class.getName());
@@ -95,6 +96,23 @@ public Resource createResource(ConfigProperties config) {
         .orElseGet(Resource::empty);
   }
 
+  @Override
+  public boolean shouldApply(ConfigProperties config, Resource resource) {
+    // we're skipping this provider if the service name was manually set by the user -- no need to
+    // waste time trying to compute the service name if it's going to be overridden anyway
+    String serviceName = config.getString("otel.service.name");
+    Map<String, String> resourceAttributes = config.getMap("otel.resource.attributes");
+    return serviceName == null
+        && !resourceAttributes.containsKey(ResourceAttributes.SERVICE_NAME.getKey())
+        && "unknown_service:java".equals(resource.getAttribute(ResourceAttributes.SERVICE_NAME));
+  }
+
+  @Override
+  public int order() {
+    // make it run later than the default set of providers
+    return 100;
+  }
+
   @Nullable
   private String findByEnvironmentVariable() {
     String result = system.getenv("SPRING_APPLICATION_NAME");

instrumentation/spring/spring-boot-resources/library/src/test/java/io/opentelemetry/instrumentation/spring/resources/SpringBootServiceNameGuesserTest.java

@@ -7,9 +7,11 @@
 
 import static io.opentelemetry.semconv.resource.attributes.ResourceAttributes.SERVICE_NAME;
 import static java.nio.charset.StandardCharsets.UTF_8;
+import static java.util.Collections.singletonMap;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.Mockito.when;
 
+import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
 import io.opentelemetry.sdk.resources.Resource;
 import java.io.OutputStream;
@@ -111,6 +113,35 @@ void getFromCommandlineArgsWithSystemProperty() throws Exception {
     expectServiceName(result, "bullpen");
   }
 
+  @Test
+  void shouldApply() {
+    SpringBootServiceNameGuesser guesser = new SpringBootServiceNameGuesser(system);
+    assertThat(guesser.shouldApply(config, Resource.getDefault())).isTrue();
+  }
+
+  @Test
+  void shouldNotApplyWhenResourceHasServiceName() {
+    SpringBootServiceNameGuesser guesser = new SpringBootServiceNameGuesser(system);
+    Resource resource =
+        Resource.getDefault().merge(Resource.create(Attributes.of(SERVICE_NAME, "test-service")));
+    assertThat(guesser.shouldApply(config, resource)).isFalse();
+  }
+
+  @Test
+  void shouldNotApplyIfConfigHasServiceName() {
+    SpringBootServiceNameGuesser guesser = new SpringBootServiceNameGuesser(system);
+    when(config.getString("otel.service.name")).thenReturn("test-service");
+    assertThat(guesser.shouldApply(config, Resource.getDefault())).isFalse();
+  }
+
+  @Test
+  void shouldNotApplyIfConfigHasServiceNameResourceAttribute() {
+    SpringBootServiceNameGuesser guesser = new SpringBootServiceNameGuesser(system);
+    when(config.getMap("otel.resource.attributes"))
+        .thenReturn(singletonMap(SERVICE_NAME.getKey(), "test-service"));
+    assertThat(guesser.shouldApply(config, Resource.getDefault())).isFalse();
+  }
+
   private static void expectServiceName(Resource result, String expected) {
     assertThat(result.getAttribute(SERVICE_NAME)).isEqualTo(expected);
   }