This feature is designed to solve the problem with the Leader service in Active Failover mode.
It attaches the deployment.arangodb.com/leader=true label to the Leader member of the cluster.
If a member is a Follower, then this label is removed.
Above labels are used by the cluster Services to route the traffic to the Leader member.
In case of double Leader situation (which will be fixed in future versions of ArangoDB),
the operator will remove the deployment.arangodb.com/leader=true label from all members,
which will cause the cluster outage.
This feature is disabled by default.
To enable it use --deployment.feature.failover-leadership arg, which needs be passed to the operator:
helm upgrade --install kube-arangodb \
https://github.com/arangodb/kube-arangodb/releases/download/$VER/kube-arangodb-$VER.tgz \
--set "operator.args={--deployment.feature.force-rebuild-out-synced-shards}"