Auto-label containers with test class and field in @Testcontainers extension

modules/junit-jupiter/src/main/java/org/testcontainers/junit/jupiter/TestcontainersExtension.java

@@ -41,6 +41,10 @@ public class TestcontainersExtension
 
     private static final String LOCAL_LIFECYCLE_AWARE_CONTAINERS = "localLifecycleAwareContainers";
 
+    private static final String TEST_CLASS_LABEL = "testcontainers/test-class";
+
+    private static final String TEST_FIELD_LABEL = "testcontainers/test-field";
+
     private final DockerAvailableDetector dockerDetector = new DockerAvailableDetector();
 
     @Override
@@ -267,12 +271,24 @@ private static class StoreAdapter implements CloseableResource, AutoCloseable {
 
         private Startable container;
 
+        private Class<?> declaringClass;
+
+        private String fieldName;
+
         private StoreAdapter(Class<?> declaringClass, String fieldName, Startable container) {
+            this.declaringClass = declaringClass;
+            this.fieldName = fieldName;
             this.key = declaringClass.getName() + "." + fieldName;
             this.container = container;
         }
 
         private StoreAdapter start() {
+            if (container instanceof org.testcontainers.containers.Container) {
+                ((org.testcontainers.containers.Container<?>) container)
+                    .withLabel(TEST_CLASS_LABEL, declaringClass.getName());
+                ((org.testcontainers.containers.Container<?>) container)
+                    .withLabel(TEST_FIELD_LABEL, fieldName);
+            }
             container.start();
             return this;
         }

modules/junit-jupiter/src/test/java/org/testcontainers/junit/jupiter/ContainerLabelingTest.java

@@ -0,0 +1,34 @@
+package org.testcontainers.junit.jupiter;
+
+import org.junit.jupiter.api.Test;
+import org.testcontainers.containers.GenericContainer;
+import org.testcontainers.containers.wait.strategy.HostPortWaitStrategy;
+import org.testcontainers.utility.DockerImageName;
+
+import java.util.Map;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class ContainerLabelingTest {
+
+    private static final DockerImageName IMAGE = DockerImageName.parse("nginx:1.27-alpine");
+
+    @Testcontainers
+    static class LabeledContainerTest {
+
+        @Container
+        @SuppressWarnings("unused")
+        static GenericContainer<?> container = new GenericContainer<>(IMAGE)
+            .withExposedPorts(80)
+            .waitingFor(new HostPortWaitStrategy());
+
+        @Test
+        void shouldHaveTestClassLabel() {
+            Map<String, String> labels = container.getContainerInfo().getConfig().getLabels();
+            assertThat(labels)
+                .containsEntry("testcontainers/test-class",
+                    ContainerLabelingTest.class.getName() + "$LabeledContainerTest")
+                .containsEntry("testcontainers/test-field", "container");
+        }
+    }
+}