[DPE-4224] Remove relation_{joined,changed}.emit() calls

lib/charms/opensearch/v0/helper_charm.py

@@ -4,10 +4,7 @@
 """Utility functions for charms related operations."""
 import re
 import typing
-from datetime import datetime
 
-from charms.data_platform_libs.v0.data_interfaces import Scope
-from charms.opensearch.v0.constants_charm import PeerRelationName
 from charms.opensearch.v0.helper_enums import BaseStrEnum
 from ops import CharmBase
 from ops.model import ActiveStatus, StatusBase
@@ -118,12 +115,3 @@ def relation_departure_reason(charm: CharmBase, relation_name: str) -> RelDepart
  return RelDepartureReason.SCALE_DOWN
 
  return RelDepartureReason.REL_BROKEN
-
-
-def trigger_leader_peer_rel_changed(charm: CharmBase) -> None:
- """Force trigger a peer rel changed event by leader."""
- if not charm.unit.is_leader():
- return
-
- charm.peers_data.put(Scope.APP, "triggered", datetime.now().timestamp())
- charm.on[PeerRelationName].relation_changed.emit(charm.model.get_relation(PeerRelationName))

lib/charms/opensearch/v0/opensearch_base_charm.py

@@ -238,6 +238,10 @@ def __init__(self, *args, distro: Type[OpenSearchDistribution] = None):
  self.framework.observe(self.on.set_password_action, self._on_set_password_action)
  self.framework.observe(self.on.get_password_action, self._on_get_password_action)
 
+ # Ensure that only one instance of the `_on_peer_relation_changed` handler exists
+ # in the deferred event queue
+ self._is_peer_rel_changed_deferred = False
+
  @property
  @abc.abstractmethod
  def _upgrade(self) -> typing.Optional[upgrade.Upgrade]:
@@ -429,8 +433,14 @@ def _on_peer_relation_changed(self, event: RelationChangedEvent):
  and self.opensearch.is_node_up()
  and self.health.apply() in [HealthColors.UNKNOWN, HealthColors.YELLOW_TEMP]
  ):
+ if self._is_peer_rel_changed_deferred:
+ # We already deferred this event during this Juju event. Retry on the next
+ # Juju event.
+ return
  # we defer because we want the temporary status to be updated
  event.defer()
+ # If the handler is called again within this Juju hook, we will abandon the event
+ self._is_peer_rel_changed_deferred = True
 
  for relation in self.model.relations.get(ClientRelationName, []):
  self.opensearch_provider.update_endpoints(relation)
@@ -593,9 +603,7 @@ def _on_config_changed(self, event: ConfigChangedEvent): # noqa C901
  # since when an IP change happens, "_on_peer_relation_joined" won't be called,
  # we need to alert the leader that it must recompute the node roles for any unit whose
  # roles were changed while the current unit was cut-off from the rest of the network
- self.on[PeerRelationName].relation_joined.emit(
- self.model.get_relation(PeerRelationName)
- )
+ self._on_peer_relation_joined(event)
 
  previous_deployment_desc = self.opensearch_peer_cm.deployment_desc()
  if self.unit.is_leader():

lib/charms/opensearch/v0/opensearch_peer_clusters.py

@@ -88,12 +88,6 @@ def run(self) -> None:
  Scope.APP, "deployment-description", deployment_desc.to_dict()
  )
 
- if deployment_desc.start == StartMode.WITH_GENERATED_ROLES:
- # role generation logic
- self._charm.on[PeerRelationName].relation_changed.emit(
- self._charm.model.get_relation(PeerRelationName)
- )
-
  self.apply_status_if_needed(deployment_desc)
 
  # TODO: once peer clusters relation implemented, we should apply all directives

lib/charms/opensearch/v0/opensearch_relation_peer_cluster.py

@@ -137,9 +137,6 @@ def _on_peer_cluster_relation_joined(self, event: RelationJoinedEvent):
 
  self.refresh_relation_data(event)
 
- # TODO: is the below still needed
- # self.charm.trigger_leader_peer_rel_changed()
-
  def _on_peer_cluster_relation_changed(self, event: RelationChangedEvent):
  """Event received by all units in sub-cluster when a new sub-cluster joins the relation."""
  if not self.charm.unit.is_leader():
@@ -415,7 +412,6 @@ def __init__(self, charm: "OpenSearchBaseCharm"):
 
  def _on_peer_cluster_relation_joined(self, event: RelationJoinedEvent):
  """Event received when a new main-failover cluster unit joins the fleet."""
- # self.charm.trigger_leader_peer_rel_changed()
  pass
 
  def _on_peer_cluster_relation_changed(self, event: RelationChangedEvent):