[DPE - 6153] - Propagate the security index intitialized through the peercluster relation

[skourta]

Fixes #516

Summary

• lib/charms/opensearch/v0/models.py: Added a new attribute security_index_initialised to the PeerClusterRelData class to track the initialization status of the security index.

• lib/charms/opensearch/v0/opensearch_base_charm.py: Added a new method put_or_update_security_index_initialized to set the security index initialization flag and notify the main orchestrator. This method is called in _post_start_init to replace the direct setting of the flag. [1] [2]

• lib/charms/opensearch/v0/opensearch_relation_peer_cluster.py: Added a method _get_security_index_initialised to check the initialization status across clusters and a method set_security_index_initialised to update the status in the unit data bag. These methods are used to ensure consistent handling of the security index initialization. [1] [2]

• lib/charms/opensearch/v0/opensearch_relation_peer_cluster.py: Updated methods _rel_data, _on_peer_cluster_relation_changed, and _set_security_conf to incorporate the new security_index_initialised attribute and ensure the status is correctly propagated and logged. [1] [2] [3]

[reneradoi]

Thank you @skourta for investigating and bringing up this solution for the issue. I think it is a valid approach and helps to set the security_index_initialized more consistently on the peer-cluster applications.

There are only some minor things that need to be adjusted from my point of view. Good Job!

[Mehdi-Bendriss]

Thanks Smail, great work!

[reneradoi]

Re-approval after PR had already been reviewed from my-side previously.