Fix bug 988034 - Quantum Network Manager - not clearing ips

Added a line in nova_ipam_lib.QuantumNovaIPAMLib init
method to ensure we clean up IPs and explanation of whats
going on.

Also, nuked release_fixed_ip as that is not
needed in QuantumManager anymore.

Change-Id: I3971b4d4c464ce68ba9370c9f5d8ca7840e0a72a

Authors

@@ -172,6 +172,7 @@ Salvatore Orlando <salvatore.orlando@eu.citrix.com>
 Sandy Walsh <sandy.walsh@rackspace.com>
 Sateesh Chodapuneedi <sateesh.chodapuneedi@citrix.com>
 Scott Moser <smoser@ubuntu.com>
+Somik Behera <somikbehera@gmail.com>
 Soren Hansen <soren.hansen@rackspace.com>
 Stanislaw Pitucha <stanislaw.pitucha@hp.com>
 Stephanie Reese <reese.sm@gmail.com>

nova/network/quantum/manager.py

@@ -668,14 +668,6 @@ def validate_networks(self, context, networks):
             if not (is_tenant_net or is_provider_net):
                 raise exception.NetworkNotFound(network_id=net_id)
 
-    # NOTE(bgh): deallocate_for_instance will take care of this..  The reason
-    # we're providing this is so that NetworkManager::release_fixed_ip() isn't
-    # called.  It does some database operations that we don't want to happen
-    # and since the majority of the stuff that it does is already taken care
-    # of in our deallocate_for_instance call we don't need to do anything.
-    def release_fixed_ip(self, context, address):
-        pass
-
     def get_dhcp_hosts_text(self, context, subnet_id, project_id=None):
         ips = self.ipam.get_allocated_ips(context, subnet_id, project_id)
         hosts_text = ""

nova/network/quantum/nova_ipam_lib.py

@@ -47,6 +47,10 @@ def __init__(self, net_manager):
         """
         self.net_manager = net_manager
 
+        # NOTE(s0mik) : If DHCP is not in use, we need to timeout IPs
+        # periodically.  See comment in deallocate_ips_by_vif for more
+        self.net_manager.timeout_fixed_ips = not self.net_manager.DHCP
+
     def create_subnet(self, context, label, tenant_id,
                       quantum_net_id, priority, cidr=None,
                       gateway=None, gateway_v6=None, cidr_v6=None,
@@ -213,6 +217,17 @@ def deallocate_ips_by_vif(self, context, tenant_id, net_id, vif_ref):
         admin_context = context.elevated()
         fixed_ips = db.fixed_ips_by_virtual_interface(admin_context,
                                                          vif_ref['id'])
+        # NOTE(s0mik): Sets fixed-ip to deallocated, but leaves the entry
+        # associated with the instance-id.  This prevents us from handing it
+        # out again immediately, as allocating it to a new instance before
+        # a DHCP lease has timed-out is bad.  Instead, the fixed-ip will
+        # be disassociated with the instance-id by a call to one of two
+        # methods inherited from FlatManager:
+        # - if DHCP is in use, a lease expiring in dnsmasq triggers
+        #   a call to release_fixed_ip in the network manager.
+        # - otherwise, _disassociate_stale_fixed_ips is called periodically
+        #   to disassociate all fixed ips that are unallocated
+        #   but still associated with an instance-id.
         for fixed_ip in fixed_ips:
             db.fixed_ip_update(admin_context, fixed_ip['address'],
                                {'allocated': False,