router: Persistent DHCP leases file on VRs and cleanup /etc/hosts on VM deletion (apache#3351)

Since the CloudStack virtual router was redesigned on version 4.6 it has been observed that the DHCP leases file is not persistent across network operations. This causes conflicts on guest VMs static IPs, causing these static IPs to not be renewed by the DHCP server running on isolated and VPC networks' virtual routers (dnsmasq). On stopping or destroying a VM, its dhcp/dns records are not removed from the virtual router causing ghost effects.

Fixes apache#3272
Fixes apache#3354

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>

Author: nvazquez

api/src/com/cloud/network/element/DhcpServiceProvider.java

@@ -37,4 +37,6 @@ boolean configDhcpSupportForSubnet(Network network, NicProfile nic, VirtualMachi
     boolean removeDhcpSupportForSubnet(Network network) throws ResourceUnavailableException;
 
     boolean setExtraDhcpOptions(Network network, long nicId, Map<Integer, String> dhcpOptions);
+
+    boolean removeDhcpEntry(Network network, NicProfile nic, VirtualMachineProfile vmProfile) throws ResourceUnavailableException;
 }

core/src/com/cloud/agent/api/routing/DhcpEntryCommand.java

@@ -35,6 +35,15 @@ public class DhcpEntryCommand extends NetworkElementCommand {
     String duid;
     private boolean isDefault;
     boolean executeInSequence = false;
+    boolean remove;
+
+    public boolean isRemove() {
+        return remove;
+    }
+
+    public void setRemove(boolean remove) {
+        this.remove = remove;
+    }
 
     protected DhcpEntryCommand() {
 

core/src/com/cloud/agent/resource/virtualnetwork/VRScripts.java

@@ -68,5 +68,4 @@ public class VRScripts {
     public static final String UPDATE_HOST_PASSWD = "update_host_passwd.sh";
 
     public static final String VR_CFG = "vr_cfg.sh";
-
 }

core/src/com/cloud/agent/resource/virtualnetwork/VirtualRoutingResource.java

@@ -22,7 +22,6 @@
 import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.nio.channels.SocketChannel;
-import org.joda.time.Duration;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -41,6 +40,7 @@
 import org.apache.cloudstack.ca.SetupKeystoreAnswer;
 import org.apache.cloudstack.utils.security.KeyStoreUtils;
 import org.apache.log4j.Logger;
+import org.joda.time.Duration;
 
 import com.cloud.agent.api.Answer;
 import com.cloud.agent.api.CheckRouterAnswer;

core/src/com/cloud/agent/resource/virtualnetwork/facade/DhcpEntryConfigItem.java

@@ -35,7 +35,7 @@ public List<ConfigItem> generateConfig(final NetworkElementCommand cmd) {
         final DhcpEntryCommand command = (DhcpEntryCommand) cmd;
 
         final VmDhcpConfig vmDhcpConfig = new VmDhcpConfig(command.getVmName(), command.getVmMac(), command.getVmIpAddress(), command.getVmIp6Address(), command.getDuid(), command.getDefaultDns(),
-                command.getDefaultRouter(), command.getStaticRoutes(), command.isDefault());
+                command.getDefaultRouter(), command.getStaticRoutes(), command.isDefault(), command.isRemove());
 
         return generateConfigItems(vmDhcpConfig);
     }

core/src/com/cloud/agent/resource/virtualnetwork/model/VmDhcpConfig.java

@@ -30,12 +30,15 @@ public class VmDhcpConfig extends ConfigBase {
     private String staticRoutes;
     private boolean defaultEntry;
 
+    // Indicate if the entry should be removed when set to true
+    private boolean remove;
+
     public VmDhcpConfig() {
         super(VM_DHCP);
     }
 
     public VmDhcpConfig(String hostName, String macAddress, String ipv4Address, String ipv6Address, String ipv6Duid, String dnsAddresses, String defaultGateway,
-            String staticRoutes, boolean defaultEntry) {
+            String staticRoutes, boolean defaultEntry, boolean remove) {
         super(VM_DHCP);
         this.hostName = hostName;
         this.macAddress = macAddress;
@@ -46,6 +49,7 @@ public VmDhcpConfig(String hostName, String macAddress, String ipv4Address, Stri
         this.defaultGateway = defaultGateway;
         this.staticRoutes = staticRoutes;
         this.defaultEntry = defaultEntry;
+        this.remove = remove;
     }
 
     public String getHostName() {
@@ -64,6 +68,14 @@ public void setMacAddress(String macAddress) {
         this.macAddress = macAddress;
     }
 
+    public boolean isRemove() {
+        return remove;
+    }
+
+    public void setRemove(boolean remove) {
+        this.remove = remove;
+    }
+
     public String getIpv4Address() {
         return ipv4Address;
     }

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

@@ -309,4 +309,8 @@ void implementNetworkElementsAndResources(DeployDestination dest, ReservationCon
      */
     boolean areRoutersRunning(final List<? extends VirtualRouter> routers);
 
+    /**
+     * Remove entry from /etc/dhcphosts and /etc/hosts on virtual routers
+     */
+    void cleanupNicDhcpDnsEntry(Network network, VirtualMachineProfile vmProfile, NicProfile nicProfile);
 }

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

@@ -2912,6 +2912,34 @@ public boolean areRoutersRunning(final List<? extends VirtualRouter> routers) {
         return true;
     }
 
+    /**
+     * Cleanup entry on VR file specified by type
+     */
+    @Override
+    public void cleanupNicDhcpDnsEntry(Network network, VirtualMachineProfile vmProfile, NicProfile nicProfile) {
+
+        final List<Provider> networkProviders = getNetworkProviders(network.getId());
+        for (final NetworkElement element : networkElements) {
+            if (networkProviders.contains(element.getProvider())) {
+                if (!_networkModel.isProviderEnabledInPhysicalNetwork(_networkModel.getPhysicalNetworkId(network), element.getProvider().getName())) {
+                    throw new CloudRuntimeException("Service provider " + element.getProvider().getName() + " either doesn't exist or is not enabled in physical network id: "
+                            + network.getPhysicalNetworkId());
+                }
+                if (vmProfile.getType() == Type.User && element.getProvider() != null) {
+                    if (_networkModel.areServicesSupportedInNetwork(network.getId(), Service.Dhcp)
+                            && _networkModel.isProviderSupportServiceInNetwork(network.getId(), Service.Dhcp, element.getProvider()) && element instanceof DhcpServiceProvider) {
+                        final DhcpServiceProvider sp = (DhcpServiceProvider) element;
+                        try {
+                            sp.removeDhcpEntry(network, nicProfile, vmProfile);
+                        } catch (ResourceUnavailableException e) {
+                            s_logger.error("Failed to remove dhcp-dns entry due to: ", e);
+                        }
+                    }
+                }
+            }
+        }
+    }
+
     /**
      * rollingRestartRouters performs restart of routers of a network by first
      * deploying a new VR and then destroying old VRs in rolling fashion. For

plugins/hypervisors/baremetal/src/com/cloud/baremetal/networkservice/BaremetalDhcpElement.java

@@ -185,4 +185,9 @@ public boolean setExtraDhcpOptions(Network network, long nicId, Map<Integer, Str
         return false;
     }
 
+    @Override
+    public boolean removeDhcpEntry(Network network, NicProfile nic, VirtualMachineProfile vmProfile) throws ResourceUnavailableException {
+        return false;
+    }
+
 }

plugins/network-elements/juniper-contrail/src/org/apache/cloudstack/network/contrail/management/ContrailElementImpl.java

@@ -379,4 +379,9 @@ public boolean removeDhcpSupportForSubnet(Network network)
     public boolean setExtraDhcpOptions(Network network, long nicId, Map<Integer, String> dhcpOptions) {
         return false;
     }
+
+    @Override
+    public boolean removeDhcpEntry(Network network, NicProfile nic, VirtualMachineProfile vmProfile) {
+        return false;
+    }
 }