Traceback (most recent call last):
  File "/opt/db/config/mongo_db_schema_creation.py", line 46, in <module>
    col_list=client.pnf_simulator.list_collection_names()
  File "/usr/local/lib/python3.6/site-packages/pymongo/database.py", line 863, in list_collection_names
    for result in self.list_collections(session=session, **kwargs)]
  File "/usr/local/lib/python3.6/site-packages/pymongo/database.py", line 826, in list_collections
    _cmd, read_pref, session)
  File "/usr/local/lib/python3.6/site-packages/pymongo/mongo_client.py", line 1461, in _retryable_read
    read_pref, session, address=address)
  File "/usr/local/lib/python3.6/site-packages/pymongo/mongo_client.py", line 1278, in _select_server
    server = topology.select_server(server_selector)
  File "/usr/local/lib/python3.6/site-packages/pymongo/topology.py", line 243, in select_server
    address))
  File "/usr/local/lib/python3.6/site-packages/pymongo/topology.py", line 200, in select_servers
    selector, server_timeout, address)
  File "/usr/local/lib/python3.6/site-packages/pymongo/topology.py", line 217, in _select_servers_loop
    (self._error_message(selector), timeout, self.description))
pymongo.errors.ServerSelectionTimeoutError: mongo-ves-client-m26e8:27017: [Errno -2] Name or service not known, Timeout: 30s, Topology Description: <TopologyDescription id: 611a976380a969d75ec25d65, topology_type: Single, servers: [<ServerDescription ('mongo-ves-client-m26e8', 27017) server_type: Unknown, rtt: None, error=AutoReconnect('mongo-ves-client-m26e8:27017: [Errno -2] Name or service not known',)>]>