set lock for hacks

magnum_cluster_api/monitor.py

@@ -17,7 +17,7 @@
 from oslo_log import log as logging
 from oslo_utils import strutils
 
-from magnum_cluster_api import clients, hacks, objects, utils
+from magnum_cluster_api import clients, hacks, objects, sync, utils
 
 LOG = logging.getLogger(__name__)
 
@@ -78,5 +78,5 @@ def poll_health_status(self):
             self.data["health_status"] = fields.ClusterHealthStatus.HEALTHY
 
         self.poll_nodegroup_replicas()
-
-        hacks.set_certificate_expiry_days(k8s_api)
+        with sync.TaskLock("set_certificate_expiry_days"):
+            hacks.set_certificate_expiry_days(k8s_api)

magnum_cluster_api/sync.py

@@ -34,3 +34,24 @@ def __init__(self, cluster_id: str, expire: int = DEFAULT_EXPIRE):
             k8s_namespace="magnum-system",
             expire=expire,
         )
+
+
+class TaskLock(sherlock.KubernetesLock):
+    """
+    A task lock that is used to lock for a certain task across all of
+    the conductor nodes.
+    """
+
+    DEFAULT_EXPIRE: int = 60
+
+    def __init__(self, task_id: str, expire: int = DEFAULT_EXPIRE):
+        sherlock.configure(
+            backend=sherlock.backends.KUBERNETES,
+            retry_interval=1,
+        )
+
+        super().__init__(
+            lock_name="task-%s" % task_id,
+            k8s_namespace="magnum-system",
+            expire=expire,
+        )