I am interested in the external data storage used by Kubernete. Kubernete is using etcd as its storage backend, but etcd contains tons of APIs and I believe Kubernete does not require all of them.
I know etcd can be deployed on an external cluster without touching the codebase of Kubernete, and that is great.
If I want to develop an alternative to etcd and serve as the storage backend for Kubernete (without changing the code of Kubernete), which etcd APIs should I support to guarantee that the full functionalitiy of Kubernete is not affected? (i.e. The Kubernete API servers cannot feel the replacement of the storage backend)
Is there a list of the key etcd APIs that are depended by Kubernete?