Service detector sets service.instance.id

Author: jack-berg

sdk-extensions/incubator/src/main/java/io/opentelemetry/sdk/extension/incubator/fileconfig/ServiceResourceDetector.java

@@ -10,7 +10,9 @@
 import io.opentelemetry.sdk.autoconfigure.spi.internal.ComponentProvider;
 import io.opentelemetry.sdk.autoconfigure.spi.internal.DefaultConfigProperties;
 import io.opentelemetry.sdk.resources.Resource;
+import io.opentelemetry.sdk.resources.ResourceBuilder;
 import java.util.Collections;
+import java.util.UUID;
 
 public class ServiceResourceDetector implements ComponentProvider<Resource> {
   @Override
@@ -25,11 +27,16 @@ public String getName() {
 
   @Override
   public Resource create(DeclarativeConfigProperties config) {
+    ResourceBuilder builder = Resource.builder();
+
     ConfigProperties properties = DefaultConfigProperties.create(Collections.emptyMap());
     String serviceName = properties.getString("otel.service.name");
     if (serviceName != null) {
-      return Resource.builder().put("service.name", serviceName).build();
+      builder.put("service.name", serviceName).build();
     }
-    return Resource.empty();
+
+    builder.put("service.instance.id", UUID.randomUUID().toString());
+
+    return builder.build();
   }
 }

sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/ServiceResourceDetectorTest.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.sdk.extension.incubator.fileconfig;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatCode;
+
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.incubator.config.DeclarativeConfigProperties;
+import io.opentelemetry.sdk.resources.Resource;
+import java.util.Objects;
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+import org.junitpioneer.jupiter.ClearSystemProperty;
+
+class ServiceResourceDetectorTest {
+
+  @Test
+  void getTypeAndName() {
+    ServiceResourceDetector detector = new ServiceResourceDetector();
+
+    assertThat(detector.getType()).isEqualTo(Resource.class);
+    assertThat(detector.getName()).isEqualTo("service");
+  }
+
+  @Test
+  @ClearSystemProperty(key = "otel.service.name")
+  void create_SystemPropertySet() {
+    System.setProperty("otel.service.name", "test");
+
+    assertThat(new ServiceResourceDetector().create(DeclarativeConfigProperties.empty()))
+        .satisfies(
+            resource -> {
+              Attributes attributes = resource.getAttributes();
+              assertThat(attributes.get(AttributeKey.stringKey("service.name"))).isEqualTo("test");
+              assertThatCode(
+                      () ->
+                          UUID.fromString(
+                              Objects.requireNonNull(
+                                  attributes.get(AttributeKey.stringKey("service.instance.id")))))
+                  .doesNotThrowAnyException();
+            });
+  }
+
+  @Test
+  void create_NoSystemProperty() {
+    assertThat(new ServiceResourceDetector().create(DeclarativeConfigProperties.empty()))
+        .satisfies(
+            resource -> {
+              Attributes attributes = resource.getAttributes();
+              assertThat(attributes.get(AttributeKey.stringKey("service.name"))).isNull();
+              assertThatCode(
+                      () ->
+                          UUID.fromString(
+                              Objects.requireNonNull(
+                                  attributes.get(AttributeKey.stringKey("service.instance.id")))))
+                  .doesNotThrowAnyException();
+            });
+  }
+}