Refactoring charm event handlers

lib/charms/mongodb/v0/mongodb.py

@@ -5,7 +5,7 @@
 import logging
 import re
 from dataclasses import dataclass
-from typing import Dict, List, Optional, Set
+from typing import Dict, List, Set
 from urllib.parse import quote_plus
 
 from bson.json_util import dumps
@@ -49,7 +49,7 @@ class MongoDBConfiguration:
     """
 
     replset: str
-    database: Optional[str]
+    database: str
     username: str
     password: str
     hosts: Set[str]

lib/charms/mongodb/v0/mongodb_tls.py

@@ -42,7 +42,7 @@
 class MongoDBTLS(Object):
     """In this class we manage client database relations."""
 
-    def __init__(self, charm, peer_relation, substrate="k8s"):
+    def __init__(self, charm, peer_relation, substrate):
         """Manager of MongoDB client relations."""
         super().__init__(charm, "client-relations")
         self.charm = charm
@@ -139,13 +139,11 @@ def _on_tls_relation_broken(self, event: RelationBrokenEvent) -> None:
             event.defer()
             return
 
-        logger.debug("Restarting mongod with TLS disabled.")
-        if self.substrate == "vm":
-            self.charm.unit.status = MaintenanceStatus("disabling TLS")
-            self.charm.restart_mongod_service()
-            self.charm.unit.status = ActiveStatus()
-        else:
-            self.charm.on_mongod_pebble_ready(event)
+        logger.info("Restarting mongod with TLS disabled.")
+        self.charm.unit.status = MaintenanceStatus("disabling TLS")
+        self.charm.delete_tls_certificate_from_workload()
+        self.charm.restart_mongod_service()
+        self.charm.unit.status = ActiveStatus()
 
     def _on_certificate_available(self, event: CertificateAvailableEvent) -> None:
         """Enable TLS when TLS certificate available."""
@@ -165,9 +163,6 @@ def _on_certificate_available(self, event: CertificateAvailableEvent) -> None:
             logger.error("An unknown certificate available.")
             return
 
-        old_cert = self.charm.get_secret(scope, "cert")
-        renewal = old_cert and old_cert != event.certificate
-
         if scope == "unit" or (scope == "app" and self.charm.unit.is_leader()):
             self.charm.set_secret(
                 scope, "chain", "\n".join(event.chain) if event.chain is not None else None
@@ -182,17 +177,12 @@ def _on_certificate_available(self, event: CertificateAvailableEvent) -> None:
             event.defer()
             return
 
-        if renewal and self.substrate == "k8s":
-            self.charm.unit.get_container("mongod").stop("mongod")
-
         logger.debug("Restarting mongod with TLS enabled.")
-        if self.substrate == "vm":
-            self.charm._push_tls_certificate_to_workload()
-            self.charm.unit.status = MaintenanceStatus("enabling TLS")
-            self.charm.restart_mongod_service()
-            self.charm.unit.status = ActiveStatus()
-        else:
-            self.charm.on_mongod_pebble_ready(event)
+
+        self.charm.push_tls_certificate_to_workload()
+        self.charm.unit.status = MaintenanceStatus("enabling TLS")
+        self.charm.restart_mongod_service()
+        self.charm.unit.status = ActiveStatus()
 
     def _waiting_for_certs(self):
         """Returns a boolean indicating whether additional certs are needed."""
@@ -276,4 +266,4 @@ def get_host(self, unit: Unit):
         if self.substrate == "vm":
             return self.charm._unit_ip(unit)
         else:
-            return self.charm.get_hostname_by_unit(unit.name)
+            return self.charm.get_hostname_for_unit(unit)