[db_migrator] Fix migration of Loopback data: handle all Loopback interfaces

scripts/db_migrator.py

@@ -178,22 +178,39 @@ def migrate_intf_table(self):
         if self.appDB is None:
             return
 
-        data = self.appDB.keys(self.appDB.APPL_DB, "INTF_TABLE:*")
-
-        if data is None:
+        # Get Lo interface corresponding to IP(v4/v6) address from CONFIG_DB.
+        configdb_data = self.configDB.get_keys('LOOPBACK_INTERFACE')
+        lo_addr_to_int = dict()
+        for int_data in configdb_data:
+            if type(int_data) == tuple and len(int_data) > 1:
+                intf_name = int_data[0]
+                intf_addr = int_data[1]
+                lo_addr_to_int.update({intf_addr: intf_name})
+
+        lo_data = self.appDB.keys(self.appDB.APPL_DB, "INTF_TABLE:*")
+        if lo_data is None:
             return
 
         if_db = []
-        for key in data:
-            if_name = key.split(":")[1]
-            if if_name == "lo":
-                self.appDB.delete(self.appDB.APPL_DB, key)
-                key = key.replace(if_name, "Loopback0")
-                log.log_info('Migrating lo entry to ' + key)
-                self.appDB.set(self.appDB.APPL_DB, key, 'NULL', 'NULL')
-
-            if '/' not in key:
-                if_db.append(key.split(":")[1])
+        for lo_row in lo_data:
+            # Example of lo_row: 'INTF_TABLE:lo:10.1.0.32/32'
+            # Delete the old row with name as 'lo'. A new row with name as Loopback will be added
+            lo_name_appdb = lo_row.split(":")[1]
+            if lo_name_appdb == "lo":
+                self.appDB.delete(self.appDB.APPL_DB, lo_row)
+                lo_addr = lo_row.split('INTF_TABLE:lo:')[1]
+                lo_name_configdb = lo_addr_to_int.get(lo_addr)
+                if lo_name_configdb is None or lo_name_configdb == '':
+                    # an unlikely case where a Loopback address is present in APPLDB, but
+                    # there is no corresponding interface for this address in CONFIGDB:
+                    # Default to legacy implementation: hardcode interface name as Loopback0
+                    lo_new_row = lo_row.replace(lo_name_appdb, "Loopback0")
+                else:
+                    lo_new_row = lo_row.replace(lo_name_appdb, lo_name_configdb)
+                self.appDB.set(self.appDB.APPL_DB, lo_new_row, 'NULL', 'NULL')
+
+            if '/' not in lo_row:
+                if_db.append(lo_row.split(":")[1])
                 continue
 
         data = self.appDB.keys(self.appDB.APPL_DB, "INTF_TABLE:*")

tests/db_migrator_input/appl_db/loopback_interface_migrate_from_1_0_1_expected.json

@@ -0,0 +1,8 @@
+{
+    "INTF_TABLE:Loopback0" : {"NULL": "NULL"},
+    "INTF_TABLE:Loopback0:10.1.0.32/32" :  {"NULL": "NULL"},
+    "INTF_TABLE:Loopback0:FC00:1::32/128" : {"NULL": "NULL"},
+    "INTF_TABLE:Loopback1" : {"NULL": "NULL"},
+    "INTF_TABLE:Loopback1:10.20.8.199/32" :  {"NULL": "NULL"},
+    "INTF_TABLE:Loopback1:2001:506:28:500::1/128" :  {"NULL": "NULL"}
+}

tests/db_migrator_input/appl_db/loopback_interface_migrate_from_1_0_1_input.json

@@ -0,0 +1,18 @@
+{
+    "INTF_TABLE:lo:10.1.0.32/32" : {
+        "scope": "global",
+        "family": "IPv4"
+    },
+    "INTF_TABLE:lo:FC00:1::32/128" : {
+        "scope": "global",
+        "family": "IPv6"
+    },
+    "INTF_TABLE:lo:10.20.8.199/32" : {
+        "scope": "global",
+        "family": "IPv4"
+    },
+    "INTF_TABLE:lo:2001:506:28:500::1/128" : {
+        "scope": "global",
+        "family": "IPv6"
+    }
+}

tests/db_migrator_input/config_db/loopback_interface_migrate_from_1_0_1_expected.json

@@ -0,0 +1,8 @@
+{
+    "LOOPBACK_INTERFACE|Loopback0" : {"NULL": "NULL"},
+    "LOOPBACK_INTERFACE|Loopback0|10.1.0.32/32" : {"NULL": "NULL"},
+    "LOOPBACK_INTERFACE|Loopback0|FC00:1::32/128" : {"NULL": "NULL"},
+    "LOOPBACK_INTERFACE|Loopback1" : {"NULL": "NULL"},
+    "LOOPBACK_INTERFACE|Loopback1|10.20.8.199/32" : {"NULL": "NULL"},
+    "LOOPBACK_INTERFACE|Loopback1|2001:506:28:500::1/128" : {"NULL": "NULL"}
+}

tests/db_migrator_input/config_db/loopback_interface_migrate_from_1_0_1_input.json

@@ -0,0 +1,7 @@
+{
+    "LOOPBACK_INTERFACE|Loopback0|10.1.0.32/32" : {"NULL": "NULL"},
+    "LOOPBACK_INTERFACE|Loopback0|FC00:1::32/128" : {"NULL": "NULL"},
+    "LOOPBACK_INTERFACE|Loopback1|10.20.8.199/32" : {"NULL": "NULL"},
+    "LOOPBACK_INTERFACE|Loopback1|2001:506:28:500::1/128" : {"NULL": "NULL"},
+    "VERSIONS|DATABASE": {"VERSION": "version_1_0_1"}
+}

tests/db_migrator_test.py

@@ -476,3 +476,45 @@ def test_warm_upgrade_to_2_0_2(self):
             expected_table = expected_db.cfgdb.get_table(table)
             diff = DeepDiff(resulting_table, expected_table, ignore_order=True)
             assert not diff
+
+class Test_Migrate_Loopback(object):
+    @classmethod
+    def setup_class(cls):
+        os.environ['UTILITIES_UNIT_TESTING'] = "2"
+
+    @classmethod
+    def teardown_class(cls):
+        os.environ['UTILITIES_UNIT_TESTING'] = "0"
+        dbconnector.dedicated_dbs['CONFIG_DB'] = None
+        dbconnector.dedicated_dbs['APPL_DB'] = None
+
+    def test_migrate_loopback_int(self):
+        dbconnector.dedicated_dbs['CONFIG_DB'] = os.path.join(mock_db_path, 'config_db', 'loopback_interface_migrate_from_1_0_1_input')
+        dbconnector.dedicated_dbs['APPL_DB'] = os.path.join(mock_db_path, 'appl_db', 'loopback_interface_migrate_from_1_0_1_input')
+
+        import db_migrator
+        dbmgtr = db_migrator.DBMigrator(None)
+        dbmgtr.migrate()
+        dbconnector.dedicated_dbs['CONFIG_DB'] = os.path.join(mock_db_path, 'config_db', 'loopback_interface_migrate_from_1_0_1_expected')
+        dbconnector.dedicated_dbs['APPL_DB'] = os.path.join(mock_db_path, 'appl_db', 'loopback_interface_migrate_from_1_0_1_expected')
+        expected_db = Db()
+
+        # verify migrated configDB
+        resulting_table = dbmgtr.configDB.get_table("LOOPBACK_INTERFACE")
+        expected_table = expected_db.cfgdb.get_table("LOOPBACK_INTERFACE")
+        diff = DeepDiff(resulting_table, expected_table, ignore_order=True)
+        assert not diff
+
+        # verify migrated appDB
+        expected_appl_db = SonicV2Connector(host='127.0.0.1')
+        expected_appl_db.connect(expected_appl_db.APPL_DB)
+        expected_keys = expected_appl_db.keys(expected_appl_db.APPL_DB, "INTF_TABLE:*")
+        expected_keys.sort()
+        resulting_keys = dbmgtr.appDB.keys(dbmgtr.appDB.APPL_DB, "INTF_TABLE:*")
+        resulting_keys.sort()
+        assert expected_keys == resulting_keys
+        for key in expected_keys:
+            resulting_keys = dbmgtr.appDB.get_all(dbmgtr.appDB.APPL_DB, key)
+            expected_keys = expected_appl_db.get_all(expected_appl_db.APPL_DB, key)
+            diff = DeepDiff(resulting_keys, expected_keys, ignore_order=True)
+            assert not diff