schema-transformer crash on delete of network

[Pedro Marques]

R1.06 branch

 2369 def delete_project_virtual_network(self, idents, meta):
 2370 network_name = idents['virtual-network']
 2371 self.current_network_set |= VirtualNetworkST.delete(network_name)
 2372 self.current_network_set.discard(network_name)
 2373 # end delete_project_virtual_network
self = <schema_transformer.to_bgp.SchemaTransformer object>
self.current_network_set = set([])
global VirtualNetworkST = <class 'schema_transformer.to_bgp.VirtualNetworkST'>
VirtualNetworkST.delete = <bound method __metaclass__.delete of <class 'schema_t
ransformer.to_bgp.VirtualNetworkST'>>
network_name = 'default-domain:monitoring:monitoring-s-orccld-0001-my_network-eubu4djkr2sh'
<type 'exceptions.TypeError'>: unsupported operand type(s) for |=: 'set' and 'NoneType'

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/schema_transformer/to_bgp.py", line 3103, in launch_arc
    transformer.process_poll_result(result)
  File "/usr/lib/python2.7/dist-packages/schema_transformer/to_bgp.py", line 2781, in process_poll_result
    func(idents, meta)
  File "/usr/lib/python2.7/dist-packages/schema_transformer/to_bgp.py", line 2371, in delete_project_virtual_network
    self.current_network_set |= VirtualNetworkST.delete(network_name)
TypeError: unsupported operand type(s) for |=: 'set' and 'NoneType'

[Sachin Bansal (sbansal)]

https://github.com/Juniper/contrail-controller/commit/a1facee33328a9c10fc29719af87564b144ac833

[Sachin Bansal (sbansal)]

The issue can happen if fmap notification for deletion of virtual network comes to schema transformer and schema transformer doesn't have any information about that network. There could be many reasons for why it didn't have information, but most common is, if you create and delete the network immediately, it is possible that the network is already deleted in cassandra by the time ifmap notifies schema transformer about its creation.

There is no impact of this bug since schema transformer will be restarted by supervisord.