Add ovsdb-timeout configuration option

ovsdb-timeout sets ovsdb_timeout in openvswitch_agent.ini, this option
is used to determine when ovsdb commands should be marked as fail. This
is helpful for large clouds or where the node is under pressure.

Change-Id: I0b0e397691c49d3fcebdd30bbe9b160789acf3c3
Closes-Bug: #1849732

config.yaml

@@ -334,3 +334,9 @@ options:
       Can be used to avoid excessive memory consumption.
       WARNING: Should be NOT LESS than 25.
       (Available from Stein)
+  ovsdb-timeout:
+    type: int
+    default:
+    description: |
+      Timeout in seconds for ovsdb commands.
+      (Available from Queens)

hooks/neutron_contexts.py

@@ -180,6 +180,7 @@ class NeutronGatewayContext(NeutronAPIContext):
             'enable_isolated_metadata': config('enable-isolated-metadata'),
             'availability_zone': get_availability_zone(),
             'enable_nfg_logging': api_settings['enable_nfg_logging'],
+            'ovsdb_timeout': config('ovsdb-timeout'),
         }
 
         ctxt['local_ip'] = get_local_ip()

templates/queens/openvswitch_agent.ini

@@ -0,0 +1,26 @@
+# queens
+###############################################################################
+# [ WARNING ]
+# Configuration file maintained by Juju. Local changes may be overwritten.
+###############################################################################
+[ovs]
+enable_tunneling = True
+local_ip = {{ local_ip }}
+bridge_mappings = {{ bridge_mappings }}
+{%- if ovsdb_timeout and ovsdb_timeout > 0 %}
+ovsdb_timeout = {{ovsdb_timeout}}
+{%- endif %}
+
+[agent]
+tunnel_types = {{ overlay_network_type }}
+l2_population = {{ l2_population }}
+enable_distributed_routing = {{ enable_dvr }}
+{% if veth_mtu -%}
+veth_mtu = {{ veth_mtu }}
+{% endif -%}
+{% if extension_drivers -%}
+extensions = {{ extension_drivers }}
+{% endif %}
+
+[securitygroup]
+firewall_driver = neutron.agent.linux.iptables_firewall.OVSHybridIptablesFirewallDriver

unit_tests/test_neutron_contexts.py

@@ -202,6 +202,8 @@ class TestNeutronGatewayContext(CharmTestCase):
         self.test_config.set('customize-failure-domain', False)
         self.test_config.set('default-availability-zone', 'nova')
 
+        self.test_config.set('ovsdb-timeout', 10)
+
         self.network_get_primary_address.side_effect = NotImplementedError
         self.unit_get.return_value = '10.5.0.1'
         # Provided by neutron-api relation
@@ -243,6 +245,7 @@ class TestNeutronGatewayContext(CharmTestCase):
             'nfg_log_burst_limit': 50,
             'nfg_log_output_base': '/var/log/firewall-logs',
             'nfg_log_rate_limit': 100,
+            'ovsdb_timeout': 10,
         })
 
     @patch.object(neutron_contexts, 'validate_nfg_log_path', lambda x: x)
@@ -270,6 +273,7 @@ class TestNeutronGatewayContext(CharmTestCase):
 
         self.test_config.set('customize-failure-domain', False)
         self.test_config.set('default-availability-zone', 'nova')
+        self.test_config.set('ovsdb-timeout', 60)
 
         self.network_get_primary_address.return_value = '192.168.20.2'
         self.unit_get.return_value = '10.5.0.1'
@@ -312,6 +316,7 @@ class TestNeutronGatewayContext(CharmTestCase):
             'nfg_log_burst_limit': 25,
             'nfg_log_output_base': None,
             'nfg_log_rate_limit': None,
+            'ovsdb_timeout': 60,
         })
 
     @patch('charmhelpers.contrib.openstack.context.relation_get')