Retry neutron agent list requests upon any exception

test_neutron_agents_are_alive only retried neutron agent list requests
when the error received was a ServiceUnavailable exception. With this
patch, the retry mechanism is extended to the more generic
NeutronClientException
We detected some faults tests failed because of a temporary 504 Gateway
Timeout error and this patch should fix that

Change-Id: I4709c7bc45dd806304fac74befb309261970ada6

tobiko/openstack/neutron/__init__.py

@@ -45,6 +45,7 @@ skip_if_is_old_ovn = _agent.skip_if_is_old_ovn
 
 NeutronClientFixture = _client.NeutronClientFixture
 ServiceUnavailable = _client.ServiceUnavailable
+NeutronClientException = _client.NeutronClientException
 neutron_client = _client.neutron_client
 get_neutron_client = _client.get_neutron_client
 find_subnet = _client.find_subnet

tobiko/openstack/neutron/_client.py

@@ -23,6 +23,7 @@ import tobiko
 from tobiko.openstack import _client
 
 
+NeutronClientException = neutronclient.exceptions.NeutronClientException
 ServiceUnavailable = neutronclient.exceptions.ServiceUnavailable
 
 

tobiko/openstack/tests/_neutron.py

@@ -44,7 +44,8 @@ def test_neutron_agents_are_alive(timeout=300., interval=5.) \
         try:
             # get Neutron agent list
             agents = neutron.list_agents()
-        except neutron.ServiceUnavailable as ex:
+        except (neutron.ServiceUnavailable,
+                neutron.NeutronClientException) as ex:
             if attempt.is_last:
                 raise
             else: