Octavia charm refernces deprecated and now removed ConnectionRefused exception from novaclient

2020-02-13 09:34:40 INFO juju-log identity-service:21: Invoking reactive handler: reactive/octavia_handlers.py:147:render
2020-02-13 09:34:41 ERROR juju-log identity-service:21: Hook error:
Traceback (most recent call last):
  File "lib/charm/openstack/api_crud.py", line 175, in create_nova_keypair
    keys = nova.keypairs.list()
  File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/novaclient/api_versions.py", line 393, in substitution
    return methods[-1].func(obj, *args, **kwargs)
  File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/novaclient/v2/keypairs.py", line 163, in list
    return self._list('/%s' % self.keypair_prefix, 'keypairs')
  File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/novaclient/base.py", line 254, in _list
    resp, body = self.api.client.get(url)
  File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/keystoneauth1/adapter.py", line 386, in get
    return self.request(url, 'GET', **kwargs)
  File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/novaclient/client.py", line 78, in request
    raise exceptions.from_response(resp, body, url, method)
novaclient.exceptions.BadRequest: Bad request (HTTP 400)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/charms/reactive/__init__.py", line 74, in main
    bus.dispatch(restricted=restricted_mode)
  File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 390, in dispatch
    _invoke(other_handlers)
  File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 359, in _invoke
    handler.invoke()
  File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 181, in invoke
    self._action(*args)
  File "/var/lib/juju/agents/unit-octavia-0/charm/reactive/octavia_handlers.py", line 158, in render
    api_crud.create_nova_keypair(identity_service, amp_key_name)
  File "lib/charm/openstack/api_crud.py", line 191, in create_nova_keypair
    nova_client.exceptions.ConnectionRefused,
AttributeError: module 'novaclient.exceptions' has no attribute 'ConnectionRefused'

2020-02-13 09:34:41 DEBUG identity-service-relation-changed Traceback (most recent call last):
2020-02-13 09:34:41 DEBUG identity-service-relation-changed File "lib/charm/openstack/api_crud.py", line 175, in create_nova_keypair
2020-02-13 09:34:41 DEBUG identity-service-relation-changed keys = nova.keypairs.list()
2020-02-13 09:34:41 DEBUG identity-service-relation-changed File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/novaclient/api_versions.py", line 393, in substitution
2020-02-13 09:34:41 DEBUG identity-service-relation-changed return methods[-1].func(obj, *args, **kwargs)
2020-02-13 09:34:41 DEBUG identity-service-relation-changed File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/novaclient/v2/keypairs.py", line 163, in list
2020-02-13 09:34:41 DEBUG identity-service-relation-changed return self._list('/%s' % self.keypair_prefix, 'keypairs')
2020-02-13 09:34:41 DEBUG identity-service-relation-changed File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/novaclient/base.py", line 254, in _list
2020-02-13 09:34:41 DEBUG identity-service-relation-changed resp, body = self.api.client.get(url)
2020-02-13 09:34:41 DEBUG identity-service-relation-changed File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/keystoneauth1/adapter.py", line 386, in get
2020-02-13 09:34:41 DEBUG identity-service-relation-changed return self.request(url, 'GET', **kwargs)
2020-02-13 09:34:41 DEBUG identity-service-relation-changed File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/novaclient/client.py", line 78, in request
2020-02-13 09:34:41 DEBUG identity-service-relation-changed raise exceptions.from_response(resp, body, url, method)
2020-02-13 09:34:41 DEBUG identity-service-relation-changed novaclient.exceptions.BadRequest: Bad request (HTTP 400)
2020-02-13 09:34:41 DEBUG identity-service-relation-changed
2020-02-13 09:34:41 DEBUG identity-service-relation-changed During handling of the above exception, another exception occurred:
2020-02-13 09:34:41 DEBUG identity-service-relation-changed
2020-02-13 09:34:41 DEBUG identity-service-relation-changed Traceback (most recent call last):
2020-02-13 09:34:41 DEBUG identity-service-relation-changed File "/var/lib/juju/agents/unit-octavia-0/charm/hooks/identity-service-relation-changed", line 22, in <module>
2020-02-13 09:34:41 DEBUG identity-service-relation-changed main()
2020-02-13 09:34:41 DEBUG identity-service-relation-changed File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/charms/reactive/__init__.py", line 74, in main
2020-02-13 09:34:41 DEBUG identity-service-relation-changed bus.dispatch(restricted=restricted_mode)
2020-02-13 09:34:41 DEBUG identity-service-relation-changed File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 390, in dispatch
2020-02-13 09:34:41 DEBUG identity-service-relation-changed _invoke(other_handlers)
2020-02-13 09:34:41 DEBUG identity-service-relation-changed File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 359, in _invoke
2020-02-13 09:34:41 DEBUG identity-service-relation-changed handler.invoke()
2020-02-13 09:34:41 DEBUG identity-service-relation-changed File "/var/lib/juju/agents/unit-octavia-0/.venv/lib/python3.6/site-packages/charms/reactive/bus.py", line 181, in invoke
2020-02-13 09:34:41 DEBUG identity-service-relation-changed self._action(*args)
2020-02-13 09:34:41 DEBUG identity-service-relation-changed File "/var/lib/juju/agents/unit-octavia-0/charm/reactive/octavia_handlers.py", line 158, in render
2020-02-13 09:34:41 DEBUG identity-service-relation-changed api_crud.create_nova_keypair(identity_service, amp_key_name)
2020-02-13 09:34:41 DEBUG identity-service-relation-changed File "lib/charm/openstack/api_crud.py", line 191, in create_nova_keypair
2020-02-13 09:34:41 DEBUG identity-service-relation-changed nova_client.exceptions.ConnectionRefused,
2020-02-13 09:34:41 DEBUG identity-service-relation-changed AttributeError: module 'novaclient.exceptions' has no attribute 'ConnectionRefused'
2020-02-13 09:34:42 ERROR juju.worker.uniter.operation runhook.go:132 hook "identity-service-relation-changed" failed: exit status 1