Ensure the detail value is not null when updating the VNC access details of the VMs with failed migrations on Host maintenance

plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtGetVncPortCommandWrapper.java

@@ -41,6 +41,7 @@ public Answer execute(final GetVncPortCommand command, final LibvirtComputingRes
             final Integer vncPort = libvirtComputingResource.getVncPort(conn, command.getName());
             return new GetVncPortAnswer(command, libvirtComputingResource.getPrivateIp(), 5900 + vncPort);
         } catch (final LibvirtException e) {
+            logger.error("Failed to get vnc port for the vm: {} due to {}", command.getName(), e.getMessage());
             return new GetVncPortAnswer(command, e.toString());
         }
     }

server/src/main/java/com/cloud/resource/ResourceManagerImpl.java

@@ -1825,10 +1825,29 @@ public Host cancelHostAsDegraded(final CancelHostAsDegradedCmd cmd) throws NoTra
     protected void setKVMVncAccess(long hostId, List<VMInstanceVO> vms) {
         for (VMInstanceVO vm : vms) {
             GetVncPortAnswer vmVncPortAnswer = (GetVncPortAnswer) _agentMgr.easySend(hostId, new GetVncPortCommand(vm.getId(), vm.getInstanceName()));
-            if (vmVncPortAnswer != null) {
-                vmInstanceDetailsDao.addDetail(vm.getId(), VmDetailConstants.KVM_VNC_ADDRESS, vmVncPortAnswer.getAddress(), true);
-                vmInstanceDetailsDao.addDetail(vm.getId(), VmDetailConstants.KVM_VNC_PORT, String.valueOf(vmVncPortAnswer.getPort()), true);
-            }
+            updateVncAccessDetailForVM(vm, vmVncPortAnswer, hostId);
+        }
+    }
+
+    private void updateVncAccessDetailForVM(VMInstanceVO vm, GetVncPortAnswer vmVncPortAnswer, long hostId) {
+        if (vm == null || vmVncPortAnswer == null) {
+            logger.warn("VM or VNC port answer is null. Cannot update VNC access details.");
+            return;
+        }
+
+        if (!vmVncPortAnswer.getResult()) {
+            logger.warn("Failed to get VNC port for VM {} on host {}. Details: {}", vm, hostId, vmVncPortAnswer.getDetails());
+            return;
+        }
+
+        String vncAddress = vmVncPortAnswer.getAddress();
+        String vncPort = String.valueOf(vmVncPortAnswer.getPort());
+        if (org.apache.commons.lang3.StringUtils.isNotBlank(vmVncPortAnswer.getAddress()) && org.apache.commons.lang3.StringUtils.isNotBlank(vncPort)) {
+            logger.info("Setting VNC access details for VM {} on host {} to address: {}, port: {}", vm, hostId, vncAddress, vncPort);
+            vmInstanceDetailsDao.addDetail(vm.getId(), VmDetailConstants.KVM_VNC_ADDRESS, vncAddress, true);
+            vmInstanceDetailsDao.addDetail(vm.getId(), VmDetailConstants.KVM_VNC_PORT, vncPort, true);
+        } else {
+            logger.warn("Unable to set VNC access details for VM {} on host {} as the address or port is blank. Address: {}, Port: {}", vm, hostId, vncAddress, vncPort);
         }
     }
 

server/src/test/java/com/cloud/resource/ResourceManagerImplTest.java

@@ -210,8 +210,10 @@ public void setup() throws Exception {
         actionEventUtilsMocked = Mockito.mockStatic(ActionEventUtils.class);
         BDDMockito.given(ActionEventUtils.onCompletedActionEvent(anyLong(), anyLong(), anyString(), anyString(), anyString(), anyLong(), anyString(), anyLong()))
                 .willReturn(1L);
+        when(getVncPortAnswerVm1.getResult()).thenReturn(true);
         when(getVncPortAnswerVm1.getAddress()).thenReturn(vm1VncAddress);
         when(getVncPortAnswerVm1.getPort()).thenReturn(vm1VncPort);
+        when(getVncPortAnswerVm2.getResult()).thenReturn(true);
         when(getVncPortAnswerVm2.getAddress()).thenReturn(vm2VncAddress);
         when(getVncPortAnswerVm2.getPort()).thenReturn(vm2VncPort);
         getVncPortCommandMockedConstruction = Mockito.mockConstruction(GetVncPortCommand.class, (mock,context) -> {