Maybe it would make sense to base an official OpenSearch operator on ECK (the official Elasticsearch and Kibana operator made by Elastic) (GitHub - elastic/cloud-on-k8s: Elastic Cloud on Kubernetes). I gave it a spin last weekend just with a trivial test on my local machine and it worked great. It was able to scale up and down one data node at a time while keeping cluster health from going red.
The most recent version of it doesn’t have an open source license. But perhaps an older version of it was published with an open source license that could be forked? Or, its design could be used as inspiration?
EDIT:
Oops, didn’t see the original message here:
using ECK does not seem to be an option (both from a license point of view and also from a technical point of view, see: Does elastic eck operators support open distro for Elasticsearch )
Sounds like it was never published with an open source license. But what makes it unusable from a technical perspective? It uses StatefulSets right now. Is that problematic?