Re-reserve released NICs when a VM resyncs to Running to restore nics_count

engine/api/src/main/java/org/apache/cloudstack/engine/orchestration/service/NetworkOrchestrationService.java

@@ -265,6 +265,12 @@ NicProfile prepareNic(VirtualMachineProfile vmProfile, DeployDestination dest, R
         throws InsufficientVirtualNetworkCapacityException, InsufficientAddressCapacityException, ConcurrentOperationException, InsufficientCapacityException,
         ResourceUnavailableException;
 
+    /**
+     * Re-reserves the Allocated nics of a VM that is Running, e.g. after its nics were released on a power report
+     * that was later reverted, and restores the active nics count of their networks.
+     */
+    void reconcileNicsForRunningVm(VirtualMachineProfile vmProfile, DeployDestination dest, ReservationContext context);
+
     /**
      * Removes the provided nic from the given vm
      * @param vm

engine/orchestration/src/main/java/com/cloud/vm/VirtualMachineManagerImpl.java

@@ -5432,6 +5432,7 @@ private void handlePowerOnReportWithNoPendingJobsOnVM(final VMInstanceVO vm) {
             ActionEventUtils.onActionEvent(User.UID_SYSTEM, Account.ACCOUNT_ID_SYSTEM, vm.getDomainId(),
                 EventTypes.EVENT_VM_START, "Out of band VM power on", vm.getId(), getApiCommandResourceTypeForVm(vm).toString());
             logger.info("VM {} is sync-ed to at Running state according to power-on report from hypervisor.", vm.getInstanceName());
+            reconcileNicsForRunningVm(vm);
             break;
 
         case Destroyed:
@@ -5456,6 +5457,20 @@ private void handlePowerOnReportWithNoPendingJobsOnVM(final VMInstanceVO vm) {
         }
     }
 
+    private void reconcileNicsForRunningVm(final VMInstanceVO vm) {
+        final VMInstanceVO runningVm = _vmDao.findById(vm.getId());
+        if (runningVm == null || runningVm.getType() != VirtualMachine.Type.User || runningVm.getState() != State.Running || runningVm.getHostId() == null
+                || _nicsDao.listByVmId(runningVm.getId()).stream().noneMatch(nic -> nic.getState() == Nic.State.Allocated)) {
+            return;
+        }
+        final Host host = _hostDao.findById(runningVm.getHostId());
+        final DataCenter dc = _entityMgr.findById(DataCenter.class, runningVm.getDataCenterId());
+        final User user = _entityMgr.findById(User.class, User.UID_SYSTEM);
+        final Account account = _entityMgr.findById(Account.class, Account.ACCOUNT_ID_SYSTEM);
+        final ReservationContext context = new ReservationContextImpl(null, null, user, account);
+        _networkMgr.reconcileNicsForRunningVm(new VirtualMachineProfileImpl(runningVm), new DeployDestination(dc, null, null, host), context);
+    }
+
     private void handlePowerOffReportWithNoPendingJobsOnVM(final VMInstanceVO vm) {
         switch (vm.getState()) {
         case Starting:

engine/orchestration/src/main/java/org/apache/cloudstack/engine/orchestration/NetworkOrchestrator.java

@@ -2187,6 +2187,26 @@ public int compare(final NicVO nic1, final NicVO nic2) {
         }
     }
 
+    @Override
+    public void reconcileNicsForRunningVm(final VirtualMachineProfile vmProfile, final DeployDestination dest, final ReservationContext context) {
+        for (final NicVO nic : _nicDao.listByVmId(vmProfile.getId())) {
+            if (nic.getState() != Nic.State.Allocated) {
+                continue;
+            }
+            try {
+                final Pair<NetworkGuru, NetworkVO> implemented = implementNetwork(nic.getNetworkId(), dest, context);
+                if (implemented == null || implemented.first() == null) {
+                    logger.warn("Unable to implement Network ID={} to reconcile NIC {} of Running Instance {}", nic.getNetworkId(), nic, vmProfile);
+                    continue;
+                }
+                prepareNic(vmProfile, dest, context, nic.getId(), implemented.second());
+                logger.info("Re-reserved NIC {} of Running Instance {}", nic, vmProfile);
+            } catch (final Exception e) {
+                logger.warn("Failed to reconcile NIC {} of Running Instance {}", nic, vmProfile, e);
+            }
+        }
+    }
+
     @Override
     public NicProfile prepareNic(final VirtualMachineProfile vmProfile, final DeployDestination dest, final ReservationContext context, final long nicId, final Network network)
             throws InsufficientVirtualNetworkCapacityException, InsufficientAddressCapacityException, ConcurrentOperationException, InsufficientCapacityException,

server/src/test/java/com/cloud/vpc/MockNetworkManagerImpl.java

@@ -758,6 +758,10 @@ public Pair<NicProfile, Integer> allocateNic(NicProfile requested, Network netwo
         return null;
     }
 
+    @Override
+    public void reconcileNicsForRunningVm(VirtualMachineProfile vmProfile, DeployDestination dest, ReservationContext context) {
+    }
+
     @Override
     public NicProfile prepareNic(VirtualMachineProfile vmProfile, DeployDestination dest, ReservationContext context, long nicId, Network network)
         throws InsufficientVirtualNetworkCapacityException, InsufficientAddressCapacityException, ConcurrentOperationException, InsufficientCapacityException,