Etcd

KMS v2 (Kubernetes KMS Provider version 2) is the stable (GA since Kubernetes 1.29, KMS v1 deprecated in 1.28 and disabled by default in 1.29) mechanism for encrypting the contents of the Kubernetes etcd datastore at rest using an external key management service. Without encryption, Kubernetes Secrets stored in etcd are base64-encoded — trivially decodable by anyone with read access to the etcd data files or a snapshot. With KMS v2 enabled, resources written to etcd — Secrets, ConfigMaps, and any other API objects selected by the EncryptionConfiguration — are encrypted before being persisted, using a unique per-object key derived locally. The envelope encryption scheme means those per-object keys are never stored in plaintext: only their encrypted form lives in etcd, and only the external KMS holds the wrapping key. The encryption configuration is declared in a file referenced by the API server’s --encryption-provider-config flag, with kms: apiVersion: v2 selecting the KMS v2 code path, and endpoint: unix:///path/to/plugin.sock pointing at the plugin’s Unix domain socket.