Add keepalived-healthcheck-interval config option

Defaults to 30s (i.e. enabled) but also allows disabling
healthchecks by setting to 0.

Change-Id: I5bb7d362f0d957237e24f79f1f82583661bed470
Closes-Bug: #1890900

config.yaml

@@ -394,3 +394,12 @@ options:
       order to support kernels with limited namespace support. i.e. Trusty.
       Changing the value after neutron DHCP agents are created will break
       access. The charm will go into a blocked state if this is attempted.
+  keepalived-healthcheck-interval:
+    type: int
+    default: 30
+    description: |
+      By default all HA routers will check their external network gateway
+      by sending a ping and if that fails they trigger a vrrp transition. This
+      option defines how frequently this check is performed. Setting this value
+      to 0 will disable the healthchecks. Note that this only applies when
+      using l3ha and dvr_snat.

hooks/neutron_ovs_context.py

@@ -201,6 +201,8 @@ class OVSPluginContext(context.NeutronContext):
         ovs_ctxt['debug'] = conf['debug']
         ovs_ctxt['prevent_arp_spoofing'] = conf['prevent-arp-spoofing']
         ovs_ctxt['enable_dpdk'] = conf['enable-dpdk']
+        ovs_ctxt['keepalived_healthcheck_interval'] = \
+            conf['keepalived-healthcheck-interval']
 
         net_dev_mtu = neutron_api_settings.get('network_device_mtu')
         if net_dev_mtu:

templates/mitaka/l3_agent.ini

@@ -11,6 +11,6 @@ agent_mode = {{ agent_mode }}
 gateway_external_network_id =
 external_network_bridge =
 {% endif %}
-{% if use_l3ha and agent_mode == 'dvr_snat' -%}
+{% if use_l3ha and agent_mode == 'dvr_snat' and keepalived_healthcheck_interval -%}
-ha_vrrp_health_check_interval = 30
+ha_vrrp_health_check_interval = {{ keepalived_healthcheck_interval }}
 {% endif %}

templates/rocky/l3_agent.ini

@@ -11,8 +11,8 @@ agent_mode = {{ agent_mode }}
 gateway_external_network_id =
 external_network_bridge =
 {% endif %}
-{% if use_l3ha and agent_mode == 'dvr_snat' -%}
+{% if use_l3ha and agent_mode == 'dvr_snat' and keepalived_healthcheck_interval -%}
-ha_vrrp_health_check_interval = 30
+ha_vrrp_health_check_interval = {{ keepalived_healthcheck_interval }}
 {% endif %}
 
 [AGENT]

templates/stein/l3_agent.ini

@@ -12,6 +12,9 @@ agent_mode = {{ agent_mode }}
 gateway_external_network_id =
 external_network_bridge =
 {% endif %}
+{% if use_l3ha and agent_mode == 'dvr_snat' and keepalived_healthcheck_interval -%}
+ha_vrrp_health_check_interval = {{ keepalived_healthcheck_interval }}
+{% endif %}
 
 [AGENT]
 extensions = {{ l3_extension_plugins }}

unit_tests/test_neutron_ovs_context.py

@@ -133,7 +133,8 @@ class OVSPluginContextTest(CharmTestCase):
                   'enable-dpdk': False,
                   'security-group-log-output-base': '/var/log/nsg.log',
                   'security-group-log-rate-limit': None,
-                  'security-group-log-burst-limit': 25}
+                  'security-group-log-burst-limit': 25,
+                  'keepalived-healthcheck-interval': 0}
 
         def mock_config(key=None):
             if key:
@@ -191,6 +192,7 @@ class OVSPluginContextTest(CharmTestCase):
             'nsg_log_output_base': '/var/log/nsg.log',
             'nsg_log_rate_limit': None,
             'nsg_log_burst_limit': 25,
+            'keepalived_healthcheck_interval': 0,
         }
         self.assertEqual(expect, napi_ctxt())
 
@@ -271,6 +273,7 @@ class OVSPluginContextTest(CharmTestCase):
             'nsg_log_output_base': None,
             'nsg_log_rate_limit': None,
             'nsg_log_burst_limit': 25,
+            'keepalived_healthcheck_interval': 30,
         }
         self.maxDiff = None
         self.assertEqual(expect, napi_ctxt())