Implemented compute_reservation_vms_update, created test

Author: TetyanaYahodska

compute/cloud-client/src/main/java/compute/reservation/UpdateVmsForReservation.java

@@ -0,0 +1,76 @@
+/*
+ * 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 compute.reservation;
+
+// [START compute_reservation_vms_update]
+
+import com.google.cloud.compute.v1.Operation;
+import com.google.cloud.compute.v1.ReservationsClient;
+import com.google.cloud.compute.v1.ReservationsResizeRequest;
+import com.google.cloud.compute.v1.ResizeReservationRequest;
+import java.io.IOException;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+public class UpdateVmsForReservation {
+
+  public static void main(String[] args)
+      throws IOException, ExecutionException, InterruptedException, TimeoutException {
+    // TODO(developer): Replace these variables before running the sample.
+    // Project ID or project number of the Cloud project you want to use.
+    String projectId = "YOUR_PROJECT_ID";
+    // The zone where the reservation is located.
+    String zone =  "us-central1-a";
+    // Name of the reservation to update.
+    String reservationName = "YOUR_RESERVATION_NAME";
+    // Number of instances to update in the reservation.
+    int numberOfVms = 3;
+
+    updateVmsForReservation(projectId, zone, reservationName, numberOfVms);
+  }
+
+  // Updates a reservation with new VM capacity.
+  public static void updateVmsForReservation(
+      String projectId, String zone, String reservationName, int numberOfVms)
+      throws IOException, ExecutionException, InterruptedException, TimeoutException {
+    // 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 (ReservationsClient reservationsClient = ReservationsClient.create()) {
+
+      ResizeReservationRequest resizeReservationRequest =
+          ResizeReservationRequest.newBuilder()
+              .setProject(projectId)
+              .setZone(zone)
+              .setReservation(reservationName)
+              .setReservationsResizeRequestResource(ReservationsResizeRequest.newBuilder()
+                  .setSpecificSkuCount(numberOfVms)
+                  .build())
+              .build();
+
+      Operation response = reservationsClient.resizeAsync(resizeReservationRequest)
+          .get(3, TimeUnit.MINUTES);
+
+      if (response.hasError()) {
+        System.out.println("Reservation update failed !!" + response);
+        return;
+      }
+      System.out.println("Reservation updated successfully: " + response.getStatus());
+    }
+  }
+}
+// [END compute_reservation_vms_update]

compute/cloud-client/src/test/java/compute/reservation/CrudOperationsReservationIT.java

@@ -99,4 +99,16 @@ public void testListReservation() throws IOException {
     assertThat(reservations).isNotNull();
     Assert.assertTrue(reservations.get(0).getName().contains("test-"));
   }
+
+  @Test
+  public void testUpdateVmsForReservation()
+      throws IOException, ExecutionException, InterruptedException, TimeoutException {
+    int newNumberOfVms = 5;
+    UpdateVmsForReservation.updateVmsForReservation(
+        PROJECT_ID, ZONE, RESERVATION_NAME, newNumberOfVms);
+    Reservation reservation = GetReservation.getReservation(
+        PROJECT_ID, RESERVATION_NAME, ZONE);
+
+    Assert.assertEquals(newNumberOfVms, reservation.getSpecificReservation().getCount());
+  }
 }