Small correction: Operators aren't a CoreOS-specific thing, and they're easy to install on any cluster.
Ultimately, the "Operator framework" is just a pattern: you represent some class of software (e.g. etcd, Elasticsearch, PostgreSQL) as a ThirdPartyResource, and you have some controller that monitors those TPRs, driving other resources toward the desired state.
Ultimately, the "Operator framework" is just a pattern: you represent some class of software (e.g. etcd, Elasticsearch, PostgreSQL) as a ThirdPartyResource, and you have some controller that monitors those TPRs, driving other resources toward the desired state.