Fix trusted dashboard relation

This change has a number of fixes:

* Do not call clear() in relation broken hook. This can lead to access
denied error given that in relation broken we no longer have access to
the data bag
* Set the trusted dashboard URL regardless of whether or not the remote
end sets any provider. There is no reason to condition the availability
of trusted dashboard on the availability of federated providers.
* Account for the case when TLS is enabled after providers are added and
update the dashboard url.

Change-Id: I4102b2c12fcbf2fe19a29cf57bc369f15fa451d2
Signed-off-by: Gabriel Adrian Samfira <gsamfira@cloudbasesolutions.com>

charms/horizon-k8s/lib/charms/horizon_k8s/v0/trusted_dashboard.py

@@ -308,7 +308,6 @@ class TrustedDashboardRequirer(Object):
         """Handle relation broken event."""
 
         logger.info("Relation broken, clearing federated providers.")
-        event.relation.data[event.app].clear()
         self.on.dashboard_changed.emit(trusted_dashboard="")
 
     def get_trusted_dashboard(self, relation_id: Optional[int] = None) -> Optional[str]:

charms/horizon-k8s/src/charm.py

@@ -214,14 +214,8 @@ class HorizonOperatorCharm(sunbeam_charm.OSBaseOperatorAPICharm):
         if not self.model.unit.is_leader():
             return
 
-        fid_providers = event.fid_providers
-        if not fid_providers:
-            logger.debug("No FID providers found, skipping update.")
-            return
-
-        logger.debug(
-            "Setting trusted dashboard provider info: %s", fid_providers
-        )
+        # Set the trusted dashboard URL regardless of whether or not the
+        # requirer sets FID providers.
         self.trusted_dashboard.set_provider_info(
             trusted_dashboard=self._websso_url
         )
@@ -299,6 +293,9 @@ class HorizonOperatorCharm(sunbeam_charm.OSBaseOperatorAPICharm):
         """Configure charm services."""
         super().configure_charm(event)
         if self.bootstrapped():
+            # Handle the case where TLS is enabled/external hostname is changed
+            # and we need to update the trusted dashboard URL in keystone.
+            self._on_trusted_dashboard_providers_changed(event)
             self.status.set(ops.model.ActiveStatus(""))
             if self.model.unit.is_leader():
                 if self.ingress_public.url:

charms/keystone-k8s/src/charm.py

@@ -673,8 +673,7 @@ class TrustedDashboardRequiresHandler(sunbeam_rhandlers.RelationHandler):
             )
 
     def _on_trusted_dashboard(self, event):
-        if self.interface.get_trusted_dashboard():
-            self.callback_f(event)
+        self.callback_f(event)
 
     def context(self):
         """Configuration context."""