Adds an optional flag to force dhcp releases on instance termination. This allows ips to be reused without having to wait for the lease to timeout.

2 files changed, 26 insertions, 0 deletions

diff --git a/nova/network/linux_net.py b/nova/network/linux_net.py
index c058e93f3..2f9805fa3 100755
--- a/nova/network/linux_net.py
+++ b/nova/network/linux_net.py
@@ -550,6 +550,10 @@ def get_dhcp_opts(context, network_ref):
     return '\n'.join(hosts)
 
 
+def release_dhcp(dev, address, mac_address):
+    utils.execute('dhcp_release', dev, address, mac_address, run_as_root=True)
+
+
 # NOTE(ja): Sending a HUP only reloads the hostfile, so any
 #           configuration options (like dchp-range, vlan, ...)
 #           aren't reloaded.
@@ -799,6 +803,10 @@ def unplug(network):
     return interface_driver.unplug(network)
 
 
+def get_dev(network):
+    return interface_driver.get_dev(network)
+
+
 class LinuxNetInterfaceDriver(object):
     """Abstract class that defines generic network host API"""
     """ for for all Linux interface drivers."""
@@ -811,6 +819,11 @@ class LinuxNetInterfaceDriver(object):
         """Destory Linux device, return device name"""
         raise NotImplementedError()
 
+    def get_dev(self, network):
+        """Get device name"""
+        raise NotImplementedError()
+
+
 
 # plugs interfaces using Linux Bridge
 class LinuxBridgeInterfaceDriver(LinuxNetInterfaceDriver):
@@ -832,6 +845,9 @@ class LinuxBridgeInterfaceDriver(LinuxNetInterfaceDriver):
         return network['bridge']
 
     def unplug(self, network):
+        return self.get_dev(network)
+
+    def get_dev(self, network):
         return network['bridge']
 
     @classmethod
@@ -956,6 +972,9 @@ class LinuxOVSInterfaceDriver(LinuxNetInterfaceDriver):
         return dev
 
     def unplug(self, network):
+        return self.get_dev(network)
+
+    def get_dev(self, network):
         dev = "gw-" + str(network['id'])
         return dev
 
diff --git a/nova/network/manager.py b/nova/network/manager.py
index 70e51888f..5c2bc60f1 100644
--- a/nova/network/manager.py
+++ b/nova/network/manager.py
@@ -110,6 +110,8 @@ flags.DEFINE_string('network_host', socket.gethostname(),
                     'Network host to use for ip allocation in flat modes')
 flags.DEFINE_bool('fake_call', False,
                   'If True, skip using the queue and make local calls')
+flags.DEFINE_bool('force_dhcp_release', False,
+                  'If True, send a dhcp release on instance termination')
 
 
 class AddressAlreadyAllocated(exception.Error):
@@ -629,6 +631,11 @@ class NetworkManager(manager.SchedulerDependentManager):
         instance_id = instance_ref['id']
         self._do_trigger_security_group_members_refresh_for_instance(
                                                                    instance_id)
+        if FLAGS.force_dhcp_release:
+            dev = self.driver.get_dev(fixed_ip_ref['network'])
+            vif = self.db.virtual_interface_get_by_instance_and_network(
+                    context, instance_ref['id'], fixed_ip_ref['network']['id'])
+            self.driver.release_dhcp(dev, address, vif['address'])
 
     def lease_fixed_ip(self, context, address):
         """Called by dhcp-bridge when ip is leased."""