Show availability_zone info in CLI neutron agent-list

Like nova service-list, we should show availability zone information
in agent-list result. It will leave empty if the agent is not belong
to any zone.

Change-Id: I210b3668c247f06b0c14debe22409ce99836e024
Partially-implements: blueprint add-availability-zone

neutronclient/neutron/v2_0/agent.py

@@ -29,8 +29,8 @@ class ListAgent(neutronV20.ListCommand):
     """List agents."""
 
     resource = 'agent'
-    list_columns = ['id', 'agent_type', 'host', 'alive', 'admin_state_up',
+    list_columns = ['id', 'agent_type', 'host', 'availability_zone', 'alive',
-                    'binary']
+                    'admin_state_up', 'binary']
     _formatters = {'heartbeat_timestamp': _format_timestamp}
     sorting_support = True
 

neutronclient/tests/unit/test_cli20_agents.py

@@ -54,6 +54,22 @@ class CLITestV20Agent(test_cli20.CLITestV20Base):
         self.assertIn("alive", ag.keys())
         self.assertIn(smile, ag.values())
 
+    def test_list_agents_zone_field(self):
+        contents = {'agents': [{'availability_zone': 'myzone'}]}
+        args = ['-f', 'json']
+        resources = "agents"
+
+        cmd = agent.ListAgent(test_cli20.MyApp(sys.stdout), None)
+        self._test_list_columns(cmd, resources, contents, args)
+        _str = self.fake_stdout.make_string()
+
+        returned_agents = jsonutils.loads(_str)
+        self.assertEqual(1, len(returned_agents))
+        ag = returned_agents[0]
+        self.assertEqual(1, len(ag))
+        self.assertIn("availability_zone", ag.keys())
+        self.assertIn('myzone', ag.values())
+
     def test_update_agent(self):
         # agent-update myid --admin-state-down --description mydescr.
         resource = 'agent'