VMI was not removed and it held on VRF.

Problem:
Sequence of events goes like this:
- Delete is issued on VMI. This reset configurer in VMI and mark it for
deletion. However because of some reference entry is still present.
- Add is issued. As entry is present in DB this will convert to change
operation. On seeing a change delete flag is cleared but VMI does not get its
configurer back. Agent just resyncs the entry.
- Delete is issued again. Since configurer was not set resync for entry is not
called to flush off VMI parameters, hence VRF reference is held.

Results in Vrf Delete timeout.

Solution:
Resync will always be done for non deleted entry. In above case on add, delete
flags has been reset and entry is no more in deleted state. So whenever resync
is done, set the configurer.
Also OnDelete calls resync to flush VMI parameters. Reset of configurer should
be done after resync call is done in OnDelete.

Change-Id: I431cc3dcf264a23a0e2e1491c23ee2f8a257aba4
Closes-bug: #1550459

src/vnsw/agent/oper/test/test_logical_intf.cc

@@ -154,6 +154,65 @@ TEST_F(IntfTest, basic_1) {
     client->WaitForIdle();
 }
 
+//https://bugs.launchpad.net/juniperopenstack/r3.0/+bug/1550459
+TEST_F(IntfTest, bug_1550459) {
+    AddVrf("vrf1");
+    AddVn("vn1", 1);
+    AddPhysicalInterface("pi1", 1, "pi1");
+    AddLogicalInterface("li1", 1, "li1", 100);
+    AddLink("physical-interface", "pi1", "logical-interface", "li1");
+
+    AddVmi(1, 1);
+    client->WaitForIdle();
+    AddLink(1, 1);
+    client->WaitForIdle();
+    AddLink("virtual-network", "vn1", "routing-instance", "vrf1");
+    AddLink("virtual-machine-interface", "vmi1",
+            "virtual-network", "vn1");
+    AddLink("virtual-machine-interface-routing-instance", "vmi1",
+            "routing-instance", "vrf1",
+            "virtual-machine-interface-routing-instance");
+    AddLink("virtual-machine-interface-routing-instance", "vmi1",
+            "virtual-machine-interface", "vmi1",
+            "virtual-machine-interface-routing-instance");
+    client->WaitForIdle();
+
+    WAIT_FOR(1000, 100, (LogicalInterfaceGet(1, "li1") != NULL));
+    client->WaitForIdle();
+    LogicalInterface *li = LogicalInterfaceGet(1, "li1");
+
+    WAIT_FOR(1000, 100, (li->vm_interface() != NULL));
+    client->WaitForIdle();
+    InterfaceRef vmi_ref = li->vm_interface();
+    VmInterface *vmi = static_cast<VmInterface *>(vmi_ref.get());
+    VmInterface::Delete(Agent::GetInstance()->interface_table(),
+                        vmi->GetUuid(), VmInterface::CONFIG);
+    client->WaitForIdle();
+    AddVmi(1, 1);
+    client->WaitForIdle();
+    VmInterface::Delete(Agent::GetInstance()->interface_table(),
+                        vmi->GetUuid(), VmInterface::CONFIG);
+    client->WaitForIdle();
+
+    DelLink(1, 1);
+    DelLink("virtual-network", "vn1", "routing-instance", "vrf1");
+    DelLink("virtual-machine-interface", "vmi1",
+            "virtual-network", "vn1");
+    DelLink("virtual-machine-interface-routing-instance", "vmi1",
+            "routing-instance", "vrf1");
+    DelLink("virtual-machine-interface-routing-instance", "vmi1",
+            "virtual-machine-interface", "vmi1");
+    client->WaitForIdle();
+    DelLink("physical-interface", "pi1", "logical-interface", "li1");
+    vmi_ref.reset();
+    DelVmi(1);
+    DeleteLogicalInterface("li1");
+    DeletePhysicalInterface("pi1");
+    DelVrf("vrf1");
+    DelVn("vn1");
+    client->WaitForIdle();
+}
+
 int main(int argc, char **argv) {
     GETUSERARGS();
 

src/vnsw/agent/oper/vm_interface.cc

@@ -1687,9 +1687,9 @@ bool VmInterfaceConfigData::OnDelete(const InterfaceTable *table,
     if (vmi->IsConfigurerSet(VmInterface::CONFIG) == false)
         return true;
 
-    vmi->ResetConfigurer(VmInterface::CONFIG);
     VmInterfaceConfigData data(NULL, NULL);
     vmi->Resync(table, &data);
+    vmi->ResetConfigurer(VmInterface::CONFIG);
     return true;
 }
 
@@ -1710,6 +1710,7 @@ bool VmInterfaceConfigData::OnResync(const InterfaceTable *table,
         ecmp_load_balance_changed || static_route_config_changed)
         *force_update = true;
 
+    vmi->SetConfigurer(VmInterface::CONFIG);
     return ret;
 }
 
@@ -2093,9 +2094,9 @@ bool VmInterfaceNovaData::OnDelete(const InterfaceTable *table,
     if (vmi->IsConfigurerSet(VmInterface::INSTANCE_MSG) == false)
         return true;
 
-    vmi->ResetConfigurer(VmInterface::CONFIG);
     VmInterfaceConfigData data(NULL, NULL);
     vmi->Resync(table, &data);
+    vmi->ResetConfigurer(VmInterface::CONFIG);
     vmi->ResetConfigurer(VmInterface::INSTANCE_MSG);
     return true;
 }