Merge pull request #1358 from anarkiwi/master

 Check for duplicate YAML keys.

faucet/config_parser_util.py

@@ -21,6 +21,20 @@
 import os
 # pytype: disable=pyi-error
 import yaml
+from yaml.constructor import ConstructorError
+
+
+def no_duplicates_constructor(loader, node, deep=False):
+    """Check for duplicate YAML keys."""
+    keys = set()
+    for key_node, _ in node.value:
+        key = loader.construct_object(key_node, deep=deep)
+        if key in keys:
+            raise ConstructorError('duplicate key %s' % key)
+        keys.add(key)
+    return loader.construct_mapping(node, deep)
+
+yaml.add_constructor(yaml.resolver.BaseResolver.DEFAULT_MAPPING_TAG, no_duplicates_constructor)
 
 
 def get_logger(logname):
@@ -33,8 +47,8 @@ def read_config(config_file, logname):
     logger = get_logger(logname)
     try:
         with open(config_file, 'r') as stream:
-            conf = yaml.safe_load(stream)
-    except (yaml.YAMLError, UnicodeDecodeError, PermissionError) as err:
+            conf = yaml.load(stream.read())
+    except (yaml.YAMLError, UnicodeDecodeError, PermissionError) as err: # pytype: disable=name-error
         logger.error('Error in file %s (%s)', config_file, str(err))
         return None
     return conf

tests/test_config.py

@@ -752,6 +752,25 @@ def test_invalid_dp_conf(self):
 """
         self.check_config_failure(config, cp.dp_parser)
 
+    def test_duplicate_keys_conf(self):
+        """Test duplicate top level keys."""
+        config = """
+vlans:
+    office:
+        vid: 100
+vlans:
+    office:
+        vid: 100
+dps:
+    sw1:
+        dp_id: 0x1
+        interfaces:
+            testing:
+                number: 1
+                native_vlan: office
+"""
+        self.check_config_failure(config, cp.dp_parser)
+
 
 if __name__ == "__main__":
     unittest.main()