Add Spring Boot service version finder / ResourceProvider

Author: Hayanesh

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

@@ -293,6 +293,11 @@ InputStream openClasspathResource(String filename) {
       return classLoader.getResourceAsStream(path);
     }
 
+    InputStream openClasspathResource(String filename, String location) {
+      String path = location + "/" + filename;
+      return classLoader.getResourceAsStream(path);
+    }
+
     InputStream openFile(String filename) throws Exception {
       return Files.newInputStream(Paths.get(filename));
     }

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

@@ -0,0 +1,64 @@
+package io.opentelemetry.instrumentation.spring.resources;
+
+import static java.util.logging.Level.FINE;
+
+import com.google.auto.service.AutoService;
+import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
+import io.opentelemetry.sdk.autoconfigure.spi.ResourceProvider;
+import io.opentelemetry.sdk.resources.Resource;
+import io.opentelemetry.semconv.ResourceAttributes;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Optional;
+import java.util.Properties;
+import java.util.logging.Logger;
+import io.opentelemetry.instrumentation.spring.resources.SpringBootServiceNameDetector.SystemHelper;
+
+@AutoService(ResourceProvider.class)
+public class SpringBootServiceVersionDetector implements ResourceProvider {
+
+  private static final Logger logger =
+      Logger.getLogger(SpringBootServiceVersionDetector.class.getName());
+
+  private final SystemHelper system;
+
+  public SpringBootServiceVersionDetector() {
+    this.system = new SystemHelper();
+  }
+
+  // Exists for testing
+  public SpringBootServiceVersionDetector(SystemHelper system){
+    this.system = system;
+  }
+
+  @Override
+  public Resource createResource(ConfigProperties config) {
+    return getServiceVersionFromBuildInfo()
+        .map(version -> {
+          logger.log(FINE, "Auto-detected Spring Boot service version: {0}", version);
+          return Resource.builder().put(ResourceAttributes.SERVICE_VERSION, version).build();
+        })
+        .orElseGet(Resource::empty);
+  }
+
+
+  private Optional<String> getServiceVersionFromBuildInfo(){
+    try(InputStream in = system.openClasspathResource("build-info.properties", "META-INF")){
+      return getServiceVersionPropertyFromStream(in);
+    }catch (Exception e){
+      return Optional.empty();
+    }
+  }
+
+  private static Optional<String> getServiceVersionPropertyFromStream(InputStream in){
+    Properties properties = new Properties();
+    try {
+      // Note: load() uses ISO 8859-1 encoding, same as spring uses by default for property files
+      properties.load(in);
+      return Optional.ofNullable(properties.getProperty("build.version"));
+    } catch (IOException e) {
+      return Optional.empty();
+    }
+  }
+
+}

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

@@ -0,0 +1,40 @@
+package io.opentelemetry.instrumentation.spring.resources;
+
+import static io.opentelemetry.semconv.ResourceAttributes.SERVICE_VERSION;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.when;
+
+import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
+import io.opentelemetry.sdk.resources.Resource;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import java.io.InputStream;
+
+@ExtendWith(MockitoExtension.class)
+class SpringBootServiceVersionDetectorTest {
+
+  static final String BUILD_PROPS = "build-info.properties";
+  static final String META_INFO = "META-INF";
+
+  @Mock
+  ConfigProperties config;
+  @Mock
+  SpringBootServiceNameDetector.SystemHelper system;
+
+  @Test
+  void givenBuildVersionIsPresentInBuildInfProperties_thenReturnBuildVersion() {
+    when(system.openClasspathResource(BUILD_PROPS, META_INFO))
+        .thenReturn(openClasspathResource(META_INFO + "/" + BUILD_PROPS));
+
+    SpringBootServiceVersionDetector guesser = new SpringBootServiceVersionDetector(system);
+    Resource result = guesser.createResource(config);
+    assertThat(result.getAttribute(SERVICE_VERSION)).isEqualTo("0.0.2");
+  }
+
+  private InputStream openClasspathResource(String resource) {
+    return getClass().getClassLoader().getResourceAsStream(resource);
+  }
+
+}

instrumentation/spring/spring-boot-resources/library/src/test/resources/META-INF/build-info.properties

@@ -0,0 +1,3 @@
+build.artifact=something
+build.name=some-name
+build.version=0.0.2