@Override
  public Map<String, String> getNexusVSMCredentialsByClusterId(Long clusterId) {
    CiscoNexusVSMDeviceVO nexusVSM = null;
    ClusterVSMMapVO vsmMapVO = null;

    vsmMapVO = _vsmMapDao.findByClusterId(clusterId);
    long vsmId = 0;
    if (vsmMapVO != null) {
      vsmId = vsmMapVO.getVsmId();
      s_logger.info("vsmId is " + vsmId);
      nexusVSM = _nexusDao.findById(vsmId);
      s_logger.info("Fetching nexus vsm credentials from database.");
    } else {
      s_logger.info("Found empty vsmMapVO.");
      return null;
    }

    Map<String, String> nexusVSMCredentials = new HashMap<String, String>();
    if (nexusVSM != null) {
      nexusVSMCredentials.put("vsmip", nexusVSM.getipaddr());
      nexusVSMCredentials.put("vsmusername", nexusVSM.getUserName());
      nexusVSMCredentials.put("vsmpassword", nexusVSM.getPassword());
      s_logger.info("Successfully fetched the credentials of Nexus VSM.");
    }
    return nexusVSMCredentials;
  }
  @Override
  public boolean implement(
      Network network, NetworkOffering offering, DeployDestination dest, ReservationContext context)
      throws ConcurrentOperationException, ResourceUnavailableException,
          InsufficientCapacityException {
    DataCenter zone = _configMgr.getZone(network.getDataCenterId());

    if (zone.getNetworkType() == NetworkType.Basic) {
      s_logger.debug("Not handling network implement in zone of type " + NetworkType.Basic);
      return false;
    }

    if (!canHandle(network)) {
      return false;
    }

    List<CiscoVnmcControllerVO> devices =
        _ciscoVnmcDao.listByPhysicalNetwork(network.getPhysicalNetworkId());
    if (devices.isEmpty()) {
      s_logger.error("No Cisco Vnmc device on network " + network.getName());
      return false;
    }

    List<CiscoAsa1000vDeviceVO> asaList =
        _ciscoAsa1000vDao.listByPhysicalNetwork(network.getPhysicalNetworkId());
    if (asaList.isEmpty()) {
      s_logger.debug("No Cisco ASA 1000v device on network " + network.getName());
      return false;
    }

    NetworkAsa1000vMapVO asaForNetwork = _networkAsa1000vMapDao.findByNetworkId(network.getId());
    if (asaForNetwork != null) {
      s_logger.debug("Cisco ASA 1000v device already associated with network " + network.getName());
      return true;
    }

    if (!_networkModel.isProviderSupportServiceInNetwork(
        network.getId(), Service.SourceNat, Provider.CiscoVnmc)) {
      s_logger.error(
          "SourceNat service is not provided by Cisco Vnmc device on network " + network.getName());
      return false;
    }

    Transaction txn = Transaction.currentTxn();
    boolean status = false;
    try {
      txn.start();

      // ensure that there is an ASA 1000v assigned to this network
      CiscoAsa1000vDevice assignedAsa = assignAsa1000vToNetwork(network);
      if (assignedAsa == null) {
        s_logger.error("Unable to assign ASA 1000v device to network " + network.getName());
        return false;
      }

      ClusterVO asaCluster = _clusterDao.findById(assignedAsa.getClusterId());
      ClusterVSMMapVO clusterVsmMap = _clusterVsmMapDao.findByClusterId(assignedAsa.getClusterId());
      if (clusterVsmMap == null) {
        s_logger.error(
            "Vmware cluster "
                + asaCluster.getName()
                + " has no Cisco Nexus VSM device associated with it");
        return false;
      }

      CiscoNexusVSMDeviceVO vsmDevice = _vsmDeviceDao.findById(clusterVsmMap.getVsmId());
      if (vsmDevice == null) {
        s_logger.error(
            "Unable to load details of Cisco Nexus VSM device associated with cluster "
                + asaCluster.getName());
        return false;
      }

      CiscoVnmcControllerVO ciscoVnmcDevice = devices.get(0);
      HostVO ciscoVnmcHost = _hostDao.findById(ciscoVnmcDevice.getHostId());
      _hostDao.loadDetails(ciscoVnmcHost);
      Account owner = context.getAccount();
      PublicIp sourceNatIp = _ipAddrMgr.assignSourceNatIpAddressToGuestNetwork(owner, network);
      String vlan = network.getBroadcastUri().getHost();
      long vlanId = Long.parseLong(vlan);

      List<VlanVO> vlanVOList =
          _vlanDao.listVlansByPhysicalNetworkId(network.getPhysicalNetworkId());
      List<String> publicGateways = new ArrayList<String>();
      for (VlanVO vlanVO : vlanVOList) {
        publicGateways.add(vlanVO.getVlanGateway());
      }

      // due to VNMC limitation of not allowing source NAT ip as the outside ip of firewall,
      // an additional public ip needs to acquired for assigning as firewall outside ip.
      // In case there are already additional ip addresses available (network restart) use one
      // of them such that it is not the source NAT ip
      IpAddress outsideIp = null;
      List<IPAddressVO> publicIps = _ipAddressDao.listByAssociatedNetwork(network.getId(), null);
      for (IPAddressVO ip : publicIps) {
        if (!ip.isSourceNat()) {
          outsideIp = ip;
          break;
        }
      }
      if (outsideIp == null) { // none available, acquire one
        try {
          Account caller = CallContext.current().getCallingAccount();
          long callerUserId = CallContext.current().getCallingUserId();
          outsideIp = _ipAddrMgr.allocateIp(owner, false, caller, callerUserId, zone);
        } catch (ResourceAllocationException e) {
          s_logger.error("Unable to allocate additional public Ip address. Exception details " + e);
          return false;
        }

        try {
          outsideIp =
              _ipAddrMgr.associateIPToGuestNetwork(outsideIp.getId(), network.getId(), true);
        } catch (ResourceAllocationException e) {
          s_logger.error(
              "Unable to assign allocated additional public Ip "
                  + outsideIp.getAddress().addr()
                  + " to network with vlan "
                  + vlanId
                  + ". Exception details "
                  + e);
          return false;
        }
      }

      // create logical edge firewall in VNMC
      String gatewayNetmask = NetUtils.getCidrNetmask(network.getCidr());
      // due to ASA limitation of allowing single subnet to be assigned to firewall interfaces,
      // all public ip addresses must be from same subnet, this essentially means single public
      // subnet in zone
      if (!createLogicalEdgeFirewall(
          vlanId,
          network.getGateway(),
          gatewayNetmask,
          outsideIp.getAddress().addr(),
          sourceNatIp.getNetmask(),
          publicGateways,
          ciscoVnmcHost.getId())) {
        s_logger.error(
            "Failed to create logical edge firewall in Cisco VNMC device for network "
                + network.getName());
        return false;
      }

      // create stuff in VSM for ASA device
      if (!configureNexusVsmForAsa(
          vlanId,
          network.getGateway(),
          vsmDevice.getUserName(),
          vsmDevice.getPassword(),
          vsmDevice.getipaddr(),
          assignedAsa.getInPortProfile(),
          ciscoVnmcHost.getId())) {
        s_logger.error(
            "Failed to configure Cisco Nexus VSM "
                + vsmDevice.getipaddr()
                + " for ASA device for network "
                + network.getName());
        return false;
      }

      // configure source NAT
      if (!configureSourceNat(vlanId, network.getCidr(), sourceNatIp, ciscoVnmcHost.getId())) {
        s_logger.error(
            "Failed to configure source NAT in Cisco VNMC device for network " + network.getName());
        return false;
      }

      // associate Asa 1000v instance with logical edge firewall
      if (!associateAsaWithLogicalEdgeFirewall(
          vlanId, assignedAsa.getManagementIp(), ciscoVnmcHost.getId())) {
        s_logger.error(
            "Failed to associate Cisco ASA 1000v ("
                + assignedAsa.getManagementIp()
                + ") with logical edge firewall in VNMC for network "
                + network.getName());
        return false;
      }

      status = true;
      txn.commit();
    } finally {
      if (!status) {
        txn.rollback();
        // FIXME: also undo changes in VNMC, VSM if anything failed
      }
    }

    return true;
  }