Ensure mgmt network mtu

This will ensure that mtu is set whenever setup_hm_port()
is called regardless of if the port has just been created
or not. Also checks mtu in update-status hook.

Change-Id: I80b5cea812becd1724fcfe2a8a232253eac76735
Closes-Bug: #2018998
(cherry picked from commit f326ef267a)
(cherry picked from commit 3ebb523f89)
(cherry picked from commit 1fa839826f)
(cherry picked from commit 5747bcad93)
(cherry picked from commit 31cb8fe1eb)

src/lib/charm/openstack/api_crud.py

@@ -455,6 +455,35 @@ def wait_for_hm_port_bound(identity_service, local_unit_name):
         return False
 
 
+def ensure_hm_port_mtu(identity_service):
+    """
+    Ensure the Octavia health manager port has the same mtu as the network it
+    is attached to. This is to ensure that of the mtu changes in Neutron it is
+    reflected here as well.
+    """
+    session = session_from_identity_service(identity_service)
+    nc = init_neutron_client(session)
+    resp = nc.list_networks(tags='charm-octavia')
+    if len(resp['networks']) > 0:
+        network = resp['networks'][0]
+        ch_core.hookenv.log('ensuring mgmt network {} mtu={}'.
+                            format(network['id'], network['mtu']),
+                            level=ch_core.hookenv.DEBUG)
+        try:
+            subprocess.check_call(
+                ['ovs-vsctl', 'set', 'Interface', octavia.OCTAVIA_MGMT_INTF,
+                 'mtu={}'.format(network['mtu'])])
+            subprocess.check_call(
+                ['ip', 'link', 'set', octavia.OCTAVIA_MGMT_INTF, 'mtu',
+                 str(network['mtu'])])
+        except subprocess.CalledProcessError as exc:
+            ch_core.hookenv.log("failed to apply mtu to interface '{}': {}".
+                                format(octavia.OCTAVIA_MGMT_INTF, exc),
+                                level=ch_core.hookenv.DEBUG)
+    else:
+        ch_core.hookenv.log('mgmt network not found - cannot set mtu')
+
+
 def setup_hm_port(identity_service, octavia_charm, host_id=None):
     """Create a per unit Neutron and OVS port for Octavia Health Manager.
 
@@ -523,6 +552,10 @@ def setup_hm_port(identity_service, octavia_charm, host_id=None):
         else:
             # unknown error, raise
             raise e
+
+    # NOTE: apply this always to ensure consistency
+    ensure_hm_port_mtu(identity_service)
+
     if (not hm_port['admin_state_up'] or
             not is_hm_port_bound(identity_service,
                                  octavia_charm.local_unit_name) or

src/reactive/octavia_handlers.py

@@ -124,6 +124,17 @@ def setup_neutron_lbaas_proxy():
         neutron.publish_load_balancer_info('octavia', octavia_url)
 
 
+@reactive.when('is-update-status-hook', 'octavia.hm-port.available')
+def ensure_hm_port_mtu():
+    try:
+        identity_service = reactive.endpoint_from_flag(
+            'identity-service.available')
+        api_crud.ensure_hm_port_mtu(identity_service)
+    except Exception:
+        ch_core.hookenv.log('failed to ensure health manager port mtu',
+                            level=ch_core.hookenv.DEBUG)
+
+
 @reactive.when('config.default.enable-amphora',
                'charm.octavia.action_setup_hm_port')
 def action_setup_hm_port():

unit_tests/test_lib_charm_openstack_api_crud.py

@@ -282,6 +282,14 @@ class TestAPICrud(test_utils.PatchHelper):
             'ids', 'fake-unit-name'))
 
     def test_setup_hm_port(self):
+        self.patch_object(api_crud, 'session_from_identity_service')
+        self.patch_object(api_crud, 'init_neutron_client')
+        nc = mock.MagicMock()
+        self.init_neutron_client.return_value = nc
+        network_uuid = 'fake-network-uuid'
+        nc.list_networks.return_value = {'networks': [{'id': network_uuid,
+                                                       'mtu': 9000}]}
+
         self.patch('subprocess.check_output', 'check_output')
         self.patch('subprocess.check_call', 'check_call')
         self.patch_object(api_crud, 'get_hm_port')
@@ -328,10 +336,21 @@ class TestAPICrud(test_utils.PatchHelper):
             mock.call(['ip', 'link', 'set', 'o-hm0', 'up', 'address',
                        'fake-mac-address']),
         ])
-        self.check_call.assert_called_with(
-            ['ip', 'link', 'set', api_crud.octavia.OCTAVIA_MGMT_INTF,
-             'up', 'address', port_mac_address])
-        self.toggle_hm_port.assert_called
+        self.check_call.assert_has_calls([
+            mock.call(['ovs-vsctl', '--', 'add-port', 'br-int', 'o-hm0', '--',
+                       'set', 'Interface', 'o-hm0', 'type=internal', '--',
+                       'set', 'Interface', 'o-hm0',
+                       'external-ids:iface-status=active',
+                       '--', 'set', 'Interface', 'o-hm0',
+                       'external-ids:attached-mac=fake-mac-address', '--',
+                       'set', 'Interface', 'o-hm0',
+                       'external-ids:iface-id=fake-port-uuid',
+                       '--', 'set', 'Interface', 'o-hm0',
+                       'external-ids:skip_cleanup=true']),
+            mock.call(['ip', 'link', 'set', 'o-hm0', 'up', 'address',
+                       'fake-mac-address']),
+            mock.call(['ovs-vsctl', 'set', 'Interface', 'o-hm0', 'mtu=9000']),
+            mock.call(['ip', 'link', 'set', 'o-hm0', 'mtu', '9000'])])
 
     def test_get_port_ips(self):
         self.patch_object(api_crud, 'session_from_identity_service')

unit_tests/test_octavia_handlers.py

@@ -36,6 +36,8 @@ class TestRegisteredHooks(test_utils.TestRegisteredHooks):
         ]
         hook_set = {
             'when': {
+                'ensure_hm_port_mtu': ('is-update-status-hook',
+                                       'octavia.hm-port.available'),
                 'render': ('shared-db.available',
                            'identity-service.available',
                            'amqp.available',