feat(tpu): add tpu vm list sample. (#9606)

Implemented tpu_vm_list sample, created test

Author: TetyanaYahodska

tpu/src/main/java/tpu/ListTpuVms.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * 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
+ *
+ * http://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 tpu;
+
+//[START tpu_vm_list]
+import com.google.cloud.tpu.v2.ListNodesRequest;
+import com.google.cloud.tpu.v2.TpuClient;
+import java.io.IOException;
+
+public class ListTpuVms {
+
+  public static void main(String[] args) throws IOException {
+    // TODO(developer): Replace these variables before running the sample.
+    // Project ID or project number of the Google Cloud project you want to use.
+    String projectId = "YOUR_PROJECT_ID";
+    // The zone where the TPUs are located.
+    // For more information about supported TPU types for specific zones,
+    // see https://cloud.google.com/tpu/docs/regions-zones
+    String zone = "us-central1-f";
+
+    listTpuVms(projectId, zone);
+  }
+
+  // Lists TPU VMs in the specified zone.
+  public static TpuClient.ListNodesPage listTpuVms(String projectId, String zone)
+      throws IOException {
+    // Initialize client that will be used to send requests. This client only needs to be created
+    // once, and can be reused for multiple requests.
+    try (TpuClient tpuClient = TpuClient.create()) {
+      String parent = String.format("projects/%s/locations/%s", projectId, zone);
+
+      ListNodesRequest request = ListNodesRequest.newBuilder().setParent(parent).build();
+
+      return tpuClient.listNodes(request).getPage();
+    }
+  }
+}
+//[END tpu_vm_list]

tpu/src/test/java/tpu/TpuVmIT.java

@@ -30,12 +30,15 @@
 import com.google.cloud.tpu.v2.CreateNodeRequest;
 import com.google.cloud.tpu.v2.DeleteNodeRequest;
 import com.google.cloud.tpu.v2.GetNodeRequest;
+import com.google.cloud.tpu.v2.ListNodesRequest;
 import com.google.cloud.tpu.v2.Node;
 import com.google.cloud.tpu.v2.TpuClient;
 import com.google.cloud.tpu.v2.TpuSettings;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.PrintStream;
+import java.util.Arrays;
+import java.util.List;
 import java.util.concurrent.ExecutionException;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.Timeout;
@@ -140,4 +143,27 @@ public void testCreateTpuVmWithTopologyFlag()
       assertEquals(returnedNode, mockNode);
     }
   }
+
+  @Test
+  public void testListTpuVm() throws IOException {
+    try (MockedStatic<TpuClient> mockedTpuClient = mockStatic(TpuClient.class)) {
+      Node mockNode1 = mock(Node.class);
+      Node mockNode2 = mock(Node.class);
+      List<Node> mockListNodes = Arrays.asList(mockNode1, mockNode2);
+      TpuClient mockTpuClient = mock(TpuClient.class);
+      TpuClient.ListNodesPagedResponse mockListNodesResponse =
+          mock(TpuClient.ListNodesPagedResponse.class);
+      TpuClient.ListNodesPage mockListNodesPage = mock(TpuClient.ListNodesPage.class);
+
+      mockedTpuClient.when(TpuClient::create).thenReturn(mockTpuClient);
+      when(mockTpuClient.listNodes(any(ListNodesRequest.class))).thenReturn(mockListNodesResponse);
+      when(mockListNodesResponse.getPage()).thenReturn(mockListNodesPage);
+      when(mockListNodesPage.getValues()).thenReturn(mockListNodes);
+
+      TpuClient.ListNodesPage returnedListNodes = ListTpuVms.listTpuVms(PROJECT_ID, ZONE);
+
+      assertThat(returnedListNodes.getValues()).isEqualTo(mockListNodes);
+      verify(mockTpuClient, times(1)).listNodes(any(ListNodesRequest.class));
+    }
+  }
 }