Skip background ping checks during controllers reboot with nonDVR

When DVR is disabled, rebooting or applying network disruptions on the
controllers nodes can affect dataplane traffic because the packets are
not directly routed to the compute nodes.
Due to this, some faults tests fail during the background ping checks.
This patch skips the background ping checks on those tests.

Change-Id: If51016ce7c3562d1f18ac1f2124db72ef29c90d7

tobiko/tests/faults/ha/test_cloud_recovery.py

@@ -165,7 +165,7 @@ class DisruptTripleoNodesTest(testtools.TestCase):
     def test_0vercloud_health_check(self):
         OvercloudHealthCheck.run_before(skip_mac_table_size_test=False)
 
-    @nova.skip_background_vm_ping_checks
+    @nova.skip_background_vm_ping_checks_when_nondvr
     def test_z99_hard_reboot_controllers_recovery(self):
         OvercloudHealthCheck.run_before()
         cloud_disruptions.reset_all_controller_nodes()
@@ -215,6 +215,7 @@ class DisruptTripleoNodesTest(testtools.TestCase):
             except nova_osp.ServerNotFoundError:
                 LOG.debug(f"Server {vm_id} not found")
 
+    @nova.skip_background_vm_ping_checks_when_nondvr
     @testtools.skipIf(has_external_lb, SKIP_MESSAGE_EXTLB)
     def test_z99_reboot_controller_galera_main_vip(self):
         # This test case may fail at times if RHBZ#2124877 is not resolved
@@ -231,24 +232,28 @@ class DisruptTripleoNodesTest(testtools.TestCase):
         cloud_disruptions.check_no_duplicate_ips(
             self.vms_detailed_info, ports_before_stack_creation)
 
+    @nova.skip_background_vm_ping_checks_when_nondvr
     @testtools.skipIf(has_external_lb, SKIP_MESSAGE_EXTLB)
     def test_z99_reboot_controller_main_vip(self):
         OvercloudHealthCheck.run_before()
         cloud_disruptions.reset_controller_main_vip()
         OvercloudHealthCheck.run_after()
 
+    @nova.skip_background_vm_ping_checks_when_nondvr
     @testtools.skipIf(has_external_lb, SKIP_MESSAGE_EXTLB)
     def test_z99_reboot_controller_non_main_vip(self):
         OvercloudHealthCheck.run_before()
         cloud_disruptions.reset_controllers_non_main_vip()
         OvercloudHealthCheck.run_after()
 
+    @nova.skip_background_vm_ping_checks_when_nondvr
     @testtools.skipIf(has_external_lb, SKIP_MESSAGE_EXTLB)
     def test_z99_crash_controller_main_vip(self):
         OvercloudHealthCheck.run_before()
         cloud_disruptions.crash_controller_main_vip()
         OvercloudHealthCheck.run_after()
 
+    @nova.skip_background_vm_ping_checks_when_nondvr
     @overcloud.skip_unless_kexec_tools_installed
     @testtools.skipIf(has_external_lb, SKIP_MESSAGE_EXTLB)
     def test_z99_crash_controller_non_main_vip(self):
@@ -256,6 +261,7 @@ class DisruptTripleoNodesTest(testtools.TestCase):
         cloud_disruptions.crash_controllers_non_main_vip()
         OvercloudHealthCheck.run_after()
 
+    @nova.skip_background_vm_ping_checks_when_nondvr
     @pacemaker.skip_if_fencing_not_deployed
     @testtools.skipIf(has_external_lb, SKIP_MESSAGE_EXTLB)
     def test_network_disruptor_main_vip(self):
@@ -317,6 +323,7 @@ class DisruptTripleoNodesTest(testtools.TestCase):
         cloud_disruptions.request_galera_sst()
         OvercloudHealthCheck.run_after()
 
+    @nova.skip_background_vm_ping_checks_when_nondvr
     @pytest.mark.flaky(reruns=0)
     def test_controllers_shutdown(self):
         OvercloudHealthCheck.run_before()

tobiko/tripleo/__init__.py

@@ -54,6 +54,7 @@ skip_if_missing_overcloud = overcloud.skip_if_missing_overcloud
 skip_unless_has_overcloud = overcloud.skip_unless_has_overcloud
 get_overcloud_ssh_username = overcloud.get_overcloud_ssh_username
 skip_if_ceph_rgw = containers.skip_if_ceph_rgw
+get_container_runtime_name = containers.get_container_runtime_name
 
 get_rhosp_release = _rhosp.get_rhosp_release
 get_rhosp_version = _rhosp.get_rhosp_version

tobiko/tripleo/_overcloud.py

@@ -445,3 +445,15 @@ def setup_overcloud_keystone_credentials():
         keystone.register_default_keystone_credentials(
             credentials=overcloud_keystone_credentials(),
             position=0)
+
+
+@functools.lru_cache()
+def is_dvr_enabled():
+    controller0 = topology.list_openstack_nodes(group='controller')[0]
+    container_runtime = tripleo.get_container_runtime_name()
+    command = (f"{container_runtime} exec neutron_api crudini --get "
+               "/etc/neutron/neutron.conf DEFAULT enable_dvr")
+    enable_dvr = sh.execute(command,
+                            ssh_client=controller0.ssh_client,
+                            sudo=True).stdout.lower()
+    return "true" in enable_dvr

tobiko/tripleo/nova.py

@@ -268,7 +268,20 @@ def skip_background_vm_ping_checks(func):
     must be dropped for the duration of the test - func"""
     @wraps(func)
     def wrapper(*args):  # pylint: disable=W0613
+        tobiko.add_cleanup(skip_check_or_start_background_vm_ping)
         check_or_start_background_vm_ping()
         func(*args)
-        skip_check_or_start_background_vm_ping()
+    return wrapper
+
+
+def skip_background_vm_ping_checks_when_nondvr(func):
+    """Similar to skip_background_vm_ping_checks, but the background ping
+    checks and the restart of the background ping process is only executed when
+    DVR is disabled"""
+    @wraps(func)
+    def wrapper(*args):  # pylint: disable=W0613
+        if not overcloud.is_dvr_enabled():
+            tobiko.add_cleanup(skip_check_or_start_background_vm_ping)
+            check_or_start_background_vm_ping()
+        func(*args)
     return wrapper