Move the parsing of the otel.resource.attributes into an SPI impl (#2713)

sdk-extensions/autoconfigure/src/main/java/io/opentelemetry/sdk/autoconfigure/EnvironmentResource.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.sdk.autoconfigure;
+
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.common.AttributesBuilder;
+import io.opentelemetry.sdk.resources.ResourceProvider;
+
+public class EnvironmentResource extends ResourceProvider {
+
+  static final String ATTRIBUTE_PROPERTY = "otel.resource.attributes";
+
+  @Override
+  protected Attributes getAttributes() {
+    return getAttributes(ConfigProperties.get());
+  }
+
+  // visible for testing
+  Attributes getAttributes(ConfigProperties configProperties) {
+    AttributesBuilder resourceAttributes = Attributes.builder();
+    configProperties.getCommaSeparatedMap(ATTRIBUTE_PROPERTY).forEach(resourceAttributes::put);
+    return resourceAttributes.build();
+  }
+}

sdk-extensions/autoconfigure/src/main/java/io/opentelemetry/sdk/autoconfigure/OpenTelemetrySdkAutoConfiguration.java

@@ -5,8 +5,6 @@
 
 package io.opentelemetry.sdk.autoconfigure;
 
-import io.opentelemetry.api.common.Attributes;
-import io.opentelemetry.api.common.AttributesBuilder;
 import io.opentelemetry.context.propagation.ContextPropagators;
 import io.opentelemetry.sdk.OpenTelemetrySdk;
 import io.opentelemetry.sdk.metrics.SdkMeterProvider;
@@ -28,7 +26,7 @@ public final class OpenTelemetrySdkAutoConfiguration {
     ConfigProperties config = ConfigProperties.get();
     ContextPropagators propagators = PropagatorConfiguration.configurePropagators(config);
 
-    Resource resource = configureResource(config);
+    Resource resource = Resource.getDefault();
 
     configureMeterProvider(resource, config);
 
@@ -51,12 +49,5 @@ public final class OpenTelemetrySdkAutoConfiguration {
     }
   }
 
-  // Visible for testing
-  static Resource configureResource(ConfigProperties config) {
-    AttributesBuilder resourceAttributes = Attributes.builder();
-    config.getCommaSeparatedMap("otel.resource.attributes").forEach(resourceAttributes::put);
-    return Resource.getDefault().merge(Resource.create(resourceAttributes.build()));
-  }
-
   private OpenTelemetrySdkAutoConfiguration() {}
 }

sdk-extensions/autoconfigure/src/main/resources/META-INF/services/io.opentelemetry.sdk.resources.ResourceProvider

@@ -0,0 +1 @@
+io.opentelemetry.sdk.autoconfigure.EnvironmentResource

sdk-extensions/autoconfigure/src/test/java/io/opentelemetry/sdk/autoconfigure/EnvironmentResourceTest.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.sdk.autoconfigure;
+
+import static java.util.Collections.emptyMap;
+import static java.util.Collections.singletonMap;
+import static org.assertj.core.api.Assertions.assertThat;
+
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.semconv.resource.attributes.ResourceAttributes;
+import org.junit.jupiter.api.Test;
+
+class EnvironmentResourceTest {
+
+  @Test
+  void resourceFromConfig_empty() {
+    Attributes attributes =
+        new EnvironmentResource().getAttributes(ConfigProperties.createForTest(emptyMap()));
+
+    assertThat(attributes).isEqualTo(Attributes.empty());
+  }
+
+  @Test
+  void resourceFromConfig() {
+    Attributes attributes =
+        new EnvironmentResource()
+            .getAttributes(
+                ConfigProperties.createForTest(
+                    singletonMap(
+                        EnvironmentResource.ATTRIBUTE_PROPERTY,
+                        "service.name=myService,appName=MyApp")));
+
+    assertThat(attributes)
+        .isEqualTo(
+            Attributes.of(
+                ResourceAttributes.SERVICE_NAME,
+                "myService",
+                AttributeKey.stringKey("appName"),
+                "MyApp"));
+  }
+
+  @Test
+  void resourceFromConfig_emptyEnvVar() {
+    Attributes attributes =
+        new EnvironmentResource()
+            .getAttributes(
+                ConfigProperties.createForTest(
+                    singletonMap(EnvironmentResource.ATTRIBUTE_PROPERTY, "")));
+
+    assertThat(attributes).isEqualTo(Attributes.empty());
+  }
+}

sdk-extensions/autoconfigure/src/test/java/io/opentelemetry/sdk/autoconfigure/OpenTelemetrySdkAutoConfigurationTest.java

@@ -1,26 +0,0 @@
-/*
- * Copyright The OpenTelemetry Authors
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package io.opentelemetry.sdk.autoconfigure;
-
-import static org.assertj.core.api.Assertions.assertThat;
-
-import io.opentelemetry.sdk.resources.Resource;
-import io.opentelemetry.semconv.resource.attributes.ResourceAttributes;
-import java.util.Collections;
-import org.junit.jupiter.api.Test;
-
-class OpenTelemetrySdkAutoConfigurationTest {
-
-  @Test
-  void resourcePrioritizesUser() {
-    Resource resource =
-        OpenTelemetrySdkAutoConfiguration.configureResource(
-            ConfigProperties.createForTest(
-                Collections.singletonMap("otel.resource.attributes", "telemetry.sdk.name=test")));
-    assertThat(resource.getAttributes().get(ResourceAttributes.TELEMETRY_SDK_NAME))
-        .isEqualTo("test");
-  }
-}