Remove dependency to opentelemetry-sdk

Closes gh-37284

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/opentelemetry/OpenTelemetryAutoConfiguration.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.actuate.autoconfigure.opentelemetry;
 
+import java.util.Map.Entry;
+
 import io.opentelemetry.api.OpenTelemetry;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.context.propagation.ContextPropagators;
@@ -24,6 +26,7 @@ import io.opentelemetry.sdk.OpenTelemetrySdkBuilder;
 import io.opentelemetry.sdk.logs.SdkLoggerProvider;
 import io.opentelemetry.sdk.metrics.SdkMeterProvider;
 import io.opentelemetry.sdk.resources.Resource;
+import io.opentelemetry.sdk.resources.ResourceBuilder;
 import io.opentelemetry.sdk.trace.SdkTracerProvider;
 import io.opentelemetry.semconv.resource.attributes.ResourceAttributes;
 
@@ -71,7 +74,15 @@ public class OpenTelemetryAutoConfiguration {
 		String applicationName = environment.getProperty("spring.application.name", DEFAULT_APPLICATION_NAME);
 		return Resource.getDefault()
 			.merge(Resource.create(Attributes.of(ResourceAttributes.SERVICE_NAME, applicationName)))
-			.merge(properties.toResource());
+			.merge(toResource(properties));
+	}
+
+	private static Resource toResource(OpenTelemetryProperties properties) {
+		ResourceBuilder builder = Resource.builder();
+		for (Entry<String, String> entry : properties.getResourceAttributes().entrySet()) {
+			builder.put(entry.getKey(), entry.getValue());
+		}
+		return builder.build();
 	}
 
 }

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/opentelemetry/OpenTelemetryProperties.java

@@ -18,10 +18,6 @@ package org.springframework.boot.actuate.autoconfigure.opentelemetry;
 
 import java.util.HashMap;
 import java.util.Map;
-import java.util.Map.Entry;
-
-import io.opentelemetry.sdk.resources.Resource;
-import io.opentelemetry.sdk.resources.ResourceBuilder;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
 
@@ -47,12 +43,4 @@ public class OpenTelemetryProperties {
 		this.resourceAttributes = resourceAttributes;
 	}
 
-	Resource toResource() {
-		ResourceBuilder builder = Resource.builder();
-		for (Entry<String, String> entry : this.resourceAttributes.entrySet()) {
-			builder.put(entry.getKey(), entry.getValue());
-		}
-		return builder.build();
-	}
-
 }

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/opentelemetry/OpenTelemetryPropertiesTests.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2012-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.actuate.autoconfigure.opentelemetry;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.boot.testsupport.classpath.ClassPathExclusions;
+import org.springframework.context.annotation.Configuration;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.entry;
+
+/**
+ * Tests for {@link OpenTelemetryProperties}.
+ *
+ * @author Moritz Halbritter
+ */
+class OpenTelemetryPropertiesTests {
+
+	private final ApplicationContextRunner runner = new ApplicationContextRunner().withPropertyValues(
+			"management.opentelemetry.resource-attributes.a=alpha",
+			"management.opentelemetry.resource-attributes.b=beta");
+
+	@Test
+	@ClassPathExclusions("opentelemetry-sdk-*")
+	void shouldNotDependOnOpenTelemetrySdk() {
+		this.runner.withUserConfiguration(TestConfiguration.class).run((context) -> {
+			OpenTelemetryProperties properties = context.getBean(OpenTelemetryProperties.class);
+			assertThat(properties.getResourceAttributes()).containsOnly(entry("a", "alpha"), entry("b", "beta"));
+		});
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@EnableConfigurationProperties(OpenTelemetryProperties.class)
+	private static class TestConfiguration {
+
+	}
+
+}