Revert "[201911][db_migrator] fix old 1911 feature config migration t…

…o a new … (sonic-net#1637)"

This reverts commit 42354e6.

scripts/db_migrator.py

@@ -154,21 +154,6 @@ def migrate_intf_table(self):
             self.appDB.set(self.appDB.APPL_DB, table, 'NULL', 'NULL')
             if_db.append(if_name)
 
-    def migrate_feature_table(self):
-        '''
-        Combine CONTAINER_FEATURE and FEATURE tables into FEATURE table.
-        '''
-        feature_table = self.configDB.get_table('FEATURE')
-        for feature, config in feature_table.items():
-            state = config.pop('status', 'disabled')
-            config['state'] = state
-            self.configDB.set_entry('FEATURE', feature, config)
-
-        container_feature_table = self.configDB.get_table('CONTAINER_FEATURE')
-        for feature, config in container_feature_table.items():
-            self.configDB.mod_entry('FEATURE', feature, config)
-            self.configDB.set_entry('CONTAINER_FEATURE', feature, None)
-
     def version_unknown(self):
         """
         version_unknown tracks all SONiC versions that doesn't have a version
@@ -222,8 +207,6 @@ def version_1_0_3(self):
         """
         log.log_info('Handling version_1_0_3')
 
-        self.migrate_feature_table()
-
         # Check ASIC type, if Mellanox platform then need DB migration
         if self.asic_type == "mellanox":
             if self.mellanox_buffer_migrator.mlnx_migrate_buffer_pool_size('version_1_0_3', 'version_1_0_4') and self.mellanox_buffer_migrator.mlnx_migrate_buffer_profile('version_1_0_3', 'version_1_0_4'):
@@ -263,13 +246,15 @@ def get_version(self):
 
         return 'version_unknown'
 
+
     def set_version(self, version=None):
         if not version:
             version = self.CURRENT_VERSION
         log.log_info('Setting version to ' + version)
         entry = { self.TABLE_FIELD : version }
         self.configDB.set_entry(self.TABLE_NAME, self.TABLE_KEY, entry)
 
+
     def common_migration_ops(self):
         try:
             with open(INIT_CFG_FILE) as f:
@@ -278,16 +263,15 @@ def common_migration_ops(self):
             raise Exception(str(e))
 
         for init_cfg_table, table_val in init_db.items():
+            data = self.configDB.get_table(init_cfg_table)
+            if data:
+                # Ignore overriding the values that pre-exist in configDB
+                continue
             log.log_info("Migrating table {} from INIT_CFG to config_db".format(init_cfg_table))
-            for key in table_val:
-                curr_cfg = self.configDB.get_entry(init_cfg_table, key)
-                init_cfg = table_val[key]
-
-                # Override init config with current config.
-                # This will leave new fields from init_config
-                # in new_config, but not override existing configuration.
-                new_cfg = {**init_cfg, **curr_cfg}
-                self.configDB.set_entry(init_cfg_table, key, new_cfg)
+            # Update all tables that do not exist in configDB but are present in INIT_CFG
+            for init_table_key, init_table_val in table_val.items():
+                self.configDB.set_entry(init_cfg_table, init_table_key, init_table_val)
+
 
     def migrate(self):
         version = self.get_version()