fix(ollama): make GPU access opt-in instead of nvidia runtime detection

modules/ollama/src/main/java/org/testcontainers/ollama/OllamaContainer.java

@@ -3,22 +3,21 @@
 import com.github.dockerjava.api.DockerClient;
 import com.github.dockerjava.api.model.DeviceRequest;
 import com.github.dockerjava.api.model.Image;
-import com.github.dockerjava.api.model.Info;
-import com.github.dockerjava.api.model.RuntimeInfo;
 import org.testcontainers.DockerClientFactory;
 import org.testcontainers.containers.GenericContainer;
 import org.testcontainers.utility.DockerImageName;
 
 import java.util.Collections;
 import java.util.List;
-import java.util.Map;
 
 /**
  * Testcontainers implementation for Ollama.
  * <p>
  * Supported image: {@code ollama/ollama}
  * <p>
  * Exposed ports: 11434
+ * <p>
+ * GPU access is opt-in: use {@link #withGpuAccess()} to request access to the host GPU(s).
  */
 public class OllamaContainer extends GenericContainer<OllamaContainer> {
 
@@ -34,26 +33,34 @@ public OllamaContainer(DockerImageName dockerImageName) {
         super(dockerImageName);
         dockerImageName.assertCompatibleWith(DOCKER_IMAGE_NAME);
 
-        Info info = this.dockerClient.infoCmd().exec();
-        Map<String, RuntimeInfo> runtimes = info.getRuntimes();
-        if (runtimes != null) {
-            if (runtimes.containsKey("nvidia")) {
-                withCreateContainerCmdModifier(cmd -> {
-                    cmd
-                        .getHostConfig()
-                        .withDeviceRequests(
-                            Collections.singletonList(
-                                new DeviceRequest()
-                                    .withCapabilities(Collections.singletonList(Collections.singletonList("gpu")))
-                                    .withCount(-1)
-                            )
-                        );
-                });
-            }
-        }
         withExposedPorts(OLLAMA_PORT);
     }
 
+    /**
+     * Requests access to the host GPU(s) by adding a {@link DeviceRequest} to the container's create command.
+     * <p>
+     * GPU access is opt-in and not enabled automatically: the presence of an {@code nvidia} runtime does not
+     * guarantee that a usable GPU is present. Notably, Docker Desktop (WSL2) registers such a runtime even on
+     * machines without NVIDIA GPUs, which would make the container fail to start if a GPU device request was
+     * applied automatically.
+     *
+     * @return this
+     */
+    public OllamaContainer withGpuAccess() {
+        withCreateContainerCmdModifier(cmd -> {
+            cmd
+                .getHostConfig()
+                .withDeviceRequests(
+                    Collections.singletonList(
+                        new DeviceRequest()
+                            .withCapabilities(Collections.singletonList(Collections.singletonList("gpu")))
+                            .withCount(-1)
+                    )
+                );
+        });
+        return self();
+    }
+
     /**
      * Commits the current file system changes in the container into a new image.
      * Should be used for creating an image that contains a loaded model.

modules/ollama/src/test/java/org/testcontainers/ollama/OllamaContainerGpuTest.java

@@ -0,0 +1,65 @@
+package org.testcontainers.ollama;
+
+import com.github.dockerjava.api.command.CreateContainerCmd;
+import com.github.dockerjava.api.model.DeviceRequest;
+import com.github.dockerjava.core.command.CreateContainerCmdImpl;
+import org.junit.jupiter.api.Test;
+import org.testcontainers.containers.GenericContainer;
+import org.testcontainers.core.CreateContainerCmdModifier;
+import org.testcontainers.utility.DockerImageName;
+
+import java.lang.reflect.Field;
+import java.util.Collections;
+import java.util.Set;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Unit tests for the opt-in GPU access of {@link OllamaContainer}. The tests do not start any container: they
+ * apply the registered {@link CreateContainerCmdModifier}s to a {@link CreateContainerCmd} instance and assert
+ * on the resulting HostConfig.
+ */
+class OllamaContainerGpuTest {
+
+    @Test
+    void shouldNotRequestGpuAccessByDefault() throws Exception {
+        try (OllamaContainer container = new OllamaContainer(DockerImageName.parse("ollama/ollama"))) {
+            CreateContainerCmd createCommand = applyCreateContainerCmdModifiers(container);
+
+            assertThat(createCommand.getHostConfig().getDeviceRequests()).isNull();
+        }
+    }
+
+    @Test
+    void shouldRequestGpuAccessWhenOptedIn() throws Exception {
+        try (OllamaContainer container = new OllamaContainer(DockerImageName.parse("ollama/ollama"))) {
+            OllamaContainer result = container.withGpuAccess();
+
+            assertThat(result).isSameAs(container);
+
+            CreateContainerCmd createCommand = applyCreateContainerCmdModifiers(container);
+            DeviceRequest deviceRequest = createCommand.getHostConfig().getDeviceRequests().get(0);
+
+            assertThat(createCommand.getHostConfig().getDeviceRequests()).hasSize(1);
+            assertThat(deviceRequest.getCapabilities()).containsExactly(Collections.singletonList("gpu"));
+            assertThat(deviceRequest.getCount()).isEqualTo(-1);
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    private static CreateContainerCmd applyCreateContainerCmdModifiers(OllamaContainer container) throws Exception {
+        CreateContainerCmd createCommand = new CreateContainerCmdImpl(
+            command -> null, // the command is never executed in this test
+            null,
+            "ollama/ollama"
+        );
+
+        Field modifiersField = GenericContainer.class.getDeclaredField("createContainerCmdModifiers");
+        modifiersField.setAccessible(true);
+        Set<CreateContainerCmdModifier> modifiers = (Set<CreateContainerCmdModifier>) modifiersField.get(container);
+        for (CreateContainerCmdModifier modifier : modifiers) {
+            createCommand = modifier.modify(createCommand);
+        }
+        return createCommand;
+    }
+}