[openvpn] Avoid failing if data is empty

netdiff/parsers/openvpn.py

@@ -1,5 +1,6 @@
 import networkx
 from openvpn_status import parse_status
+from openvpn_status.parser import ParsingError
 
 from .base import BaseParser
 
@@ -13,7 +14,10 @@ class OpenvpnParser(BaseParser):
     _server_common_name = 'openvpn-server'
 
     def to_python(self, data):
-        return parse_status(data)
+        try:
+            return parse_status(data)
+        except (AttributeError, ParsingError):
+            return None
 
     def parse(self, data):
         """
@@ -25,8 +29,15 @@ def parse(self, data):
         server = self._server_common_name
         # add server (central node) to graph
         graph.add_node(server)
+        # data may be empty
+        if data is None:
+            clients = []
+            links = []
+        else:
+            clients = data.client_list.values()
+            links = data.routing_table.values()
         # add clients in graph as nodes
-        for client in data.client_list.values():
+        for client in clients:
             client_properties = {
                 'label': client.common_name,
                 'real_address': str(client.real_address.host),
@@ -44,6 +55,6 @@ def parse(self, data):
                 client_properties['local_addresses'] = local_addresses
             graph.add_node(str(client.real_address.host), **client_properties)
         # add links in routing table to graph
-        for link in data.routing_table.values():
+        for link in links:
             graph.add_edge(server, str(link.real_address.host), weight=1)
         return graph

tests/test_openvpn.py

@@ -62,3 +62,10 @@ def test_json_dict_tap(self):
         self.assertIn('nodeC', labels)
         self.assertIn('nodeD', labels)
         self.assertIn('nodeE', labels)
+
+    def test_empty_string(self):
+        OpenvpnParser(data='{}')
+
+    def test_empty_dict(self):
+        OpenvpnParser({})
+