content: // Licensed to the Apache Software Foundation (ASF) under one
  // or more contributor license agreements.  See the NOTICE file
  // distributed with this work for additional information
  // regarding copyright ownership.  The ASF licenses this file
  // to you 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 com.cloud.ha;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.stream.Collectors;
  
  import javax.inject.Inject;
  
  
  import com.cloud.agent.AgentManager;
  import com.cloud.agent.api.Answer;
  import com.cloud.agent.api.PingTestCommand;
  import com.cloud.host.Host;
  import com.cloud.host.HostVO;
  import com.cloud.host.Status;
  import com.cloud.hypervisor.Hypervisor.HypervisorType;
  import com.cloud.network.NetworkModel;
  import com.cloud.network.Networks.TrafficType;
  import com.cloud.network.router.VirtualRouter;
  import com.cloud.network.router.VpcVirtualNetworkApplianceManager;
  import com.cloud.vm.Nic;
  import com.cloud.vm.UserVmVO;
  import com.cloud.vm.VirtualMachine;
  import com.cloud.vm.dao.UserVmDao;
  
  public class UserVmDomRInvestigator extends AbstractInvestigatorImpl {
  
      @Inject
      private final UserVmDao _userVmDao = null;
      @Inject
      private final AgentManager _agentMgr = null;
      @Inject
      private final NetworkModel _networkMgr = null;
      @Inject
      private final VpcVirtualNetworkApplianceManager _vnaMgr = null;
  
      @Override
      public boolean isVmAlive(VirtualMachine vm, Host host) throws UnknownVM {
          if (vm.getType() != VirtualMachine.Type.User) {
              if (logger.isDebugEnabled()) {
                  logger.debug("Not a User Vm, unable to determine state of " + vm + " returning null");
              }
              throw new UnknownVM();
          }
  
          if (logger.isDebugEnabled()) {
              logger.debug("testing if " + vm + " is alive");
          }
          // to verify that the VM is alive, we ask the domR (router) to ping the VM (private IP)
          UserVmVO userVm = _userVmDao.findById(vm.getId());
  
          List<? extends Nic> nics = _networkMgr.getNicsForTraffic(userVm.getId(), TrafficType.Guest);
  
          for (Nic nic : nics) {
              if (nic.getIPv4Address() == null) {
                  continue;
              }
  
              List<VirtualRouter> routers = _vnaMgr.getRoutersForNetwork(nic.getNetworkId());
              if (routers == null || routers.isEmpty()) {
                  if (logger.isDebugEnabled()) {
                      logger.debug("Unable to find a router in network {} to ping {}",
                              _networkMgr.getNetwork(nic.getNetworkId()), vm);
                  }
                  continue;
              }
  
              Boolean result = null;
              for (VirtualRouter router : routers) {
                  result = testUserVM(vm, nic, router);
                  if (result != null) {
                      break;
                  }
              }
  
              if (result == null) {
                  continue;
              }
  
              return result;
          }
  
          if (logger.isDebugEnabled()) {
              logger.debug("Returning null since we're unable to determine state of " + vm);
          }
          throw new UnknownVM();
      }
  
      @Override
      public Status isAgentAlive(Host agent) {
          if (logger.isDebugEnabled()) {
              logger.debug("checking if agent ({}) is alive", agent);
          }
  
          if (agent.getPodId() == null) {
              return null;
          }
  
          List<HostVO> otherHosts = findHostByPod(agent.getPodId(), agent.getId());
  
          for (HostVO host : otherHosts) {
              if (logger.isDebugEnabled()) {
                  logger.debug("sending ping from ({}) to agent's host ip address ({})", host, agent.getPrivateIpAddress());
              }
              Status hostState = testIpAddress(host.getId(), agent.getPrivateIpAddress());
              assert hostState != null;
              // In case of Status.Unknown, next host will be tried
              if (hostState == Status.Up) {
                  if (logger.isDebugEnabled()) {
                      logger.debug("ping from ({}) to agent's host ip address ({}) successful, returning that agent is disconnected",
                              host, agent.getPrivateIpAddress());
                  }
                  return Status.Disconnected; // the computing host ip is ping-able, but the computing agent is down, report that the agent is disconnected
              } else if (hostState == Status.Down) {
                  if (logger.isDebugEnabled()) {
                      logger.debug("returning host state: " + hostState);
                  }
                  return Status.Down;
              }
          }
  
          // could not reach agent, could not reach agent's host, unclear what the problem is but it'll require more investigation...
          if (logger.isDebugEnabled()) {
              logger.debug("could not reach agent, could not reach agent's host, returning that we don't have enough information");
          }
          return null;
      }
  
      @Override
      public boolean start() {
          return true;
      }
  
      @Override
      public boolean stop() {
          return true;
      }
  
      private Boolean testUserVM(VirtualMachine vm, Nic nic, VirtualRouter router) {
          String privateIp = nic.getIPv4Address();
          String routerPrivateIp = router.getPrivateIpAddress();
  
          List<Long> otherHosts = new ArrayList<Long>();
          if (vm.getHypervisorType() == HypervisorType.XenServer || vm.getHypervisorType() == HypervisorType.KVM) {
              otherHosts.add(router.getHostId());
          } else {
              List<HostVO> otherHostsList = findHostByPod(router.getPodIdToDeployIn(), null);
              otherHosts = otherHostsList.stream().map(HostVO::getId).collect(Collectors.toList());
          }
          for (Long hostId : otherHosts) {
              try {
                  Answer pingTestAnswer = _agentMgr.easySend(hostId, new PingTestCommand(routerPrivateIp, privateIp));
                  if (pingTestAnswer != null && pingTestAnswer.getResult()) {
                      if (logger.isDebugEnabled()) {
                          logger.debug("user vm's {} ip address {}  has been successfully " +
                                  "pinged from the Virtual Router {}, returning that vm is alive",
                                  vm, privateIp, router);
                      }
                      return Boolean.TRUE;
                  }
              } catch (Exception e) {
                  if (logger.isDebugEnabled()) {
                      logger.debug("Couldn't reach due to", e);
                  }
                  continue;
              }
          }
          if (logger.isDebugEnabled()) {
              logger.debug(vm + " could not be pinged, returning that it is unknown");
          }
          return null;
  
      }
  }
  