DM: Allocate and persist irb address from each subnet of a VN for eac…

…h PR

- Allocate one ip from each subnet of a VN for each PR.
- Persist the ip and the association with VN, Subnet, PR in cassandra DB
- On DM restart, read the DB state and maintain allocated ip map in local memory
- On update/restart, find differences between allocated
  ip map vs VNC DB state of VN, and take necessary actions
- GW IP of the subnet is configured on the MX as the
  virtual-gateway-address under the IRB IP address

Change-Id: Ifcfdf96069a353cf2be1e03a83922796d4dd3471
Closes-Bug: #1465070

src/config/api-server/vnc_cfg_types.py

@@ -566,7 +566,7 @@ def http_delete_fail(cls, id, obj_dict, db_conn):
 
     @classmethod
     def ip_alloc(cls, vn_fq_name, subnet_name, count):
-        ip_list = [cls.addr_mgmt.ip_alloc_req(vn_fq_name, subnet_name)
+        ip_list = [cls.addr_mgmt.ip_alloc_req(vn_fq_name, sub=subnet_name)
                    for i in range(count)]
         msg = 'AddrMgmt: reserve %d IP for vn=%s, subnet=%s - %s' \
             % (count, vn_fq_name, subnet_name if subnet_name else '', ip_list)
@@ -580,7 +580,7 @@ def ip_free(cls, vn_fq_name, subnet_name, ip_list):
             % (ip_list, vn_fq_name, subnet_name if subnet_name else '')
         cls.addr_mgmt.config_log(msg, level=SandeshLevel.SYS_DEBUG)
         for ip_addr in ip_list:
-            cls.addr_mgmt.ip_free_req(ip_addr, vn_fq_name, subnet_name)
+            cls.addr_mgmt.ip_free_req(ip_addr, vn_fq_name, sub=subnet_name)
     # end ip_free
 
     @classmethod

src/config/common/vnc_cassandra.py

@@ -66,6 +66,33 @@ def __init__(self, server_list, reset_config, db_prefix, keyspaces, logger,
         self._obj_fq_name_cf = self._cf_dict[self._OBJ_FQ_NAME_CF_NAME]
     # end __init__
 
+    def get_cf(self, func):
+        return self._cf_dict.get(func)
+    #end
+
+    def add(self, func, key, value):
+        try:
+            self.get_cf(func).insert(key, value)
+            return True
+        except:
+            return False
+    #end
+
+    def get(self, func, key):
+        try:
+            return self.get_cf(func).get(key)
+        except:
+            return None
+    #end
+
+    def delete(self, func, key):
+        try:
+            self.get_cf(func).remove(key)
+            return True
+        except:
+            return False
+    #end
+
     def _update_sandesh_status(self, status, msg=''):
         ConnectionState.update(conn_type=ConnectionType.DATABASE,
             name='Cassandra', status=status, message=msg,