@Override
  public List<UserVmVO> listLoadBalancerInstances(ListLoadBalancerRuleInstancesCmd cmd)
      throws PermissionDeniedException {
    Account caller = UserContext.current().getCaller();
    Long loadBalancerId = cmd.getId();
    Boolean applied = cmd.isApplied();

    if (applied == null) {
      applied = Boolean.TRUE;
    }

    LoadBalancerVO loadBalancer = _lbDao.findById(loadBalancerId);
    if (loadBalancer == null) {
      return null;
    }

    _accountMgr.checkAccess(caller, null, loadBalancer);

    List<UserVmVO> loadBalancerInstances = new ArrayList<UserVmVO>();
    List<LoadBalancerVMMapVO> vmLoadBalancerMappings = null;

    vmLoadBalancerMappings = _lb2VmMapDao.listByLoadBalancerId(loadBalancerId);

    List<Long> appliedInstanceIdList = new ArrayList<Long>();
    if ((vmLoadBalancerMappings != null) && !vmLoadBalancerMappings.isEmpty()) {
      for (LoadBalancerVMMapVO vmLoadBalancerMapping : vmLoadBalancerMappings) {
        appliedInstanceIdList.add(vmLoadBalancerMapping.getInstanceId());
      }
    }

    IPAddressVO addr = _ipAddressDao.findById(loadBalancer.getSourceIpAddressId());
    List<UserVmVO> userVms =
        _vmDao.listVirtualNetworkInstancesByAcctAndZone(
            loadBalancer.getAccountId(), addr.getDataCenterId(), loadBalancer.getNetworkId());

    for (UserVmVO userVm : userVms) {
      // if the VM is destroyed, being expunged, in an error state, or in an unknown state, skip it
      switch (userVm.getState()) {
        case Destroyed:
        case Expunging:
        case Error:
        case Unknown:
          continue;
      }

      boolean isApplied = appliedInstanceIdList.contains(userVm.getId());
      if ((isApplied && applied) || (!isApplied && !applied)) {
        loadBalancerInstances.add(userVm);
      }
    }

    return loadBalancerInstances;
  }
  @Override
  public List<LbDestination> getExistingDestinations(long lbId) {
    List<LbDestination> dstList = new ArrayList<LbDestination>();
    List<LoadBalancerVMMapVO> lbVmMaps = _lb2VmMapDao.listByLoadBalancerId(lbId);
    LoadBalancerVO lb = _lbDao.findById(lbId);

    String dstIp = null;
    for (LoadBalancerVMMapVO lbVmMap : lbVmMaps) {
      UserVm vm = _vmDao.findById(lbVmMap.getInstanceId());
      Nic nic = _nicDao.findByInstanceIdAndNetworkIdIncludingRemoved(lb.getNetworkId(), vm.getId());
      dstIp = nic.getIp4Address();
      LbDestination lbDst =
          new LbDestination(
              lb.getDefaultPortStart(), lb.getDefaultPortEnd(), dstIp, lbVmMap.isRevoke());
      dstList.add(lbDst);
    }
    return dstList;
  }
  @Override
  @ActionEvent(
      eventType = EventTypes.EVENT_LOAD_BALANCER_DELETE,
      eventDescription = "deleting load balancer",
      async = true)
  public boolean deleteLoadBalancerRule(long loadBalancerId, boolean apply) {
    UserContext ctx = UserContext.current();
    Account caller = ctx.getCaller();

    LoadBalancerVO rule = _lbDao.findById(loadBalancerId);
    if (rule == null) {
      throw new InvalidParameterValueException(
          "Unable to find load balancer rule " + loadBalancerId);
    }

    _accountMgr.checkAccess(caller, null, rule);

    return deleteLoadBalancerRule(loadBalancerId, apply, caller, ctx.getCallerUserId());
  }
  @Override
  @ActionEvent(
      eventType = EventTypes.EVENT_LOAD_BALANCER_UPDATE,
      eventDescription = "updating load balancer",
      async = true)
  public LoadBalancer updateLoadBalancerRule(UpdateLoadBalancerRuleCmd cmd) {
    Long lbRuleId = cmd.getId();
    String name = cmd.getLoadBalancerName();
    String description = cmd.getDescription();
    String algorithm = cmd.getAlgorithm();
    LoadBalancerVO lb = _lbDao.findById(lbRuleId);

    if (name != null) {
      lb.setName(name);
    }

    if (description != null) {
      lb.setDescription(description);
    }

    if (algorithm != null) {
      lb.setAlgorithm(algorithm);
    }

    _lbDao.update(lbRuleId, lb);

    // If algorithm is changed, have to reapply the lb config
    if (algorithm != null) {
      try {
        lb.setState(FirewallRule.State.Add);
        _lbDao.persist(lb);
        applyLoadBalancerConfig(lbRuleId);
      } catch (ResourceUnavailableException e) {
        s_logger.warn(
            "Unable to apply the load balancer config because resource is unavaliable.", e);
      }
    }

    return lb;
  }
  private boolean removeFromLoadBalancerInternal(long loadBalancerId, List<Long> instanceIds) {
    UserContext caller = UserContext.current();

    LoadBalancerVO loadBalancer = _lbDao.findById(Long.valueOf(loadBalancerId));
    if (loadBalancer == null) {
      throw new InvalidParameterException("Invalid load balancer value: " + loadBalancerId);
    }

    _accountMgr.checkAccess(caller.getCaller(), null, loadBalancer);

    try {
      loadBalancer.setState(FirewallRule.State.Add);
      _lbDao.persist(loadBalancer);

      for (long instanceId : instanceIds) {
        LoadBalancerVMMapVO map =
            _lb2VmMapDao.findByLoadBalancerIdAndVmId(loadBalancerId, instanceId);
        map.setRevoke(true);
        _lb2VmMapDao.persist(map);
        s_logger.debug(
            "Set load balancer rule for revoke: rule id "
                + loadBalancerId
                + ", vmId "
                + instanceId);
      }

      if (!applyLoadBalancerConfig(loadBalancerId)) {
        s_logger.warn(
            "Failed to remove load balancer rule id " + loadBalancerId + " for vms " + instanceIds);
        throw new CloudRuntimeException(
            "Failed to remove load balancer rule id " + loadBalancerId + " for vms " + instanceIds);
      }

    } catch (ResourceUnavailableException e) {
      s_logger.warn("Unable to apply the load balancer config because resource is unavaliable.", e);
      return false;
    }

    return true;
  }
 @Override
 public LoadBalancerVO findById(long lbId) {
   return _lbDao.findById(lbId);
 }
 @Override
 public boolean applyLoadBalancerConfig(long lbRuleId) throws ResourceUnavailableException {
   List<LoadBalancerVO> lbs = new ArrayList<LoadBalancerVO>(1);
   lbs.add(_lbDao.findById(lbRuleId));
   return applyLoadBalancerRules(lbs);
 }
  @DB
  public boolean deleteLoadBalancerRule(
      long loadBalancerId, boolean apply, Account caller, long callerUserId) {
    LoadBalancerVO lb = _lbDao.findById(loadBalancerId);
    Transaction txn = Transaction.currentTxn();
    boolean generateUsageEvent = false;
    boolean success = true;

    txn.start();
    if (lb.getState() == FirewallRule.State.Staged) {
      if (s_logger.isDebugEnabled()) {
        s_logger.debug("Found a rule that is still in stage state so just removing it: " + lb);
      }
      generateUsageEvent = true;
    } else if (lb.getState() == FirewallRule.State.Add
        || lb.getState() == FirewallRule.State.Active) {
      lb.setState(FirewallRule.State.Revoke);
      _lbDao.persist(lb);
      generateUsageEvent = true;
    }

    List<LoadBalancerVMMapVO> maps = _lb2VmMapDao.listByLoadBalancerId(loadBalancerId);
    if (maps != null) {
      for (LoadBalancerVMMapVO map : maps) {
        map.setRevoke(true);
        _lb2VmMapDao.persist(map);
        s_logger.debug(
            "Set load balancer rule for revoke: rule id "
                + loadBalancerId
                + ", vmId "
                + map.getInstanceId());
      }
    }

    if (generateUsageEvent) {
      // Generate usage event right after all rules were marked for revoke
      UsageEventVO usageEvent =
          new UsageEventVO(
              EventTypes.EVENT_LOAD_BALANCER_DELETE, lb.getAccountId(), 0, lb.getId(), null);
      _usageEventDao.persist(usageEvent);
    }

    txn.commit();

    if (apply) {
      try {
        if (!applyLoadBalancerConfig(loadBalancerId)) {
          s_logger.warn("Unable to apply the load balancer config");
          return false;
        }
      } catch (ResourceUnavailableException e) {
        s_logger.warn(
            "Unable to apply the load balancer config because resource is unavaliable.", e);
        return false;
      }
    }

    FirewallRuleVO relatedRule = _firewallDao.findByRelatedId(lb.getId());
    if (relatedRule != null) {
      s_logger.warn(
          "Unable to remove firewall rule id="
              + lb.getId()
              + " as it has related firewall rule id="
              + relatedRule.getId()
              + "; leaving it in Revoke state");
      success = false;
    } else {
      _firewallDao.remove(lb.getId());
    }

    _elbMgr.handleDeleteLoadBalancerRule(lb, callerUserId, caller);
    if (success) {
      s_logger.debug("Load balancer with id " + lb.getId() + " is removed successfully");
    }

    return success;
  }
  @Override
  @DB
  @ActionEvent(
      eventType = EventTypes.EVENT_ASSIGN_TO_LOAD_BALANCER_RULE,
      eventDescription = "assigning to load balancer",
      async = true)
  public boolean assignToLoadBalancer(long loadBalancerId, List<Long> instanceIds) {
    UserContext ctx = UserContext.current();
    Account caller = ctx.getCaller();

    LoadBalancerVO loadBalancer = _lbDao.findById(loadBalancerId);
    if (loadBalancer == null) {
      throw new InvalidParameterValueException(
          "Failed to assign to load balancer "
              + loadBalancerId
              + ", the load balancer was not found.");
    }

    List<LoadBalancerVMMapVO> mappedInstances =
        _lb2VmMapDao.listByLoadBalancerId(loadBalancerId, false);
    Set<Long> mappedInstanceIds = new HashSet<Long>();
    for (LoadBalancerVMMapVO mappedInstance : mappedInstances) {
      mappedInstanceIds.add(Long.valueOf(mappedInstance.getInstanceId()));
    }

    List<UserVm> vmsToAdd = new ArrayList<UserVm>();

    for (Long instanceId : instanceIds) {
      if (mappedInstanceIds.contains(instanceId)) {
        throw new InvalidParameterValueException(
            "VM " + instanceId + " is already mapped to load balancer.");
      }

      UserVm vm = _vmDao.findById(instanceId);
      if (vm == null || vm.getState() == State.Destroyed || vm.getState() == State.Expunging) {
        throw new InvalidParameterValueException("Invalid instance id: " + instanceId);
      }

      _rulesMgr.checkRuleAndUserVm(loadBalancer, vm, caller);

      if (vm.getAccountId() != loadBalancer.getAccountId()) {
        throw new PermissionDeniedException(
            "Cannot add virtual machines that do not belong to the same owner.");
      }

      // Let's check to make sure the vm has a nic in the same network as the load balancing rule.
      List<? extends Nic> nics = _networkMgr.getNics(vm.getId());
      Nic nicInSameNetwork = null;
      for (Nic nic : nics) {
        if (nic.getNetworkId() == loadBalancer.getNetworkId()) {
          nicInSameNetwork = nic;
          break;
        }
      }

      if (nicInSameNetwork == null) {
        throw new InvalidParameterValueException(
            "VM " + instanceId + " cannot be added because it doesn't belong in the same network.");
      }

      if (s_logger.isDebugEnabled()) {
        s_logger.debug("Adding " + vm + " to the load balancer pool");
      }
      vmsToAdd.add(vm);
    }

    Transaction txn = Transaction.currentTxn();
    txn.start();

    for (UserVm vm : vmsToAdd) {
      LoadBalancerVMMapVO map = new LoadBalancerVMMapVO(loadBalancer.getId(), vm.getId(), false);
      map = _lb2VmMapDao.persist(map);
    }
    txn.commit();

    try {
      loadBalancer.setState(FirewallRule.State.Add);
      _lbDao.persist(loadBalancer);
      applyLoadBalancerConfig(loadBalancerId);
    } catch (ResourceUnavailableException e) {
      s_logger.warn("Unable to apply the load balancer config because resource is unavaliable.", e);
      return false;
    }

    return true;
  }