Kubernetes operator is a method of packaging, deploying and managing a Kubernetes application Kubernetes application is both deployed on Kubernetes and managed using the Kubernetes API (kubectl).

Kubernetes operator is a domain specific Kubernetes controller. The term was introduced by the CoreOS people.

__All operators use the controller pattern, but no all controller are operators. __ Operator has controller pattern and adds new objects to Kubernetes API.

Some Example Operators

etcd-operator: Create and manage etcd clusters on Kubernetes. etcd is a distributed key-value store.

prometheus-operator: Create and manage Prometheus clusters on Kubernetes. Prometheus is monitoring and alerting toolkit.

vault-operator: Create and manage Vault clusters on Kubernetes. Vault stores and distributes secrets such as API tokens and other credentials for your application.

rook-operator: Create and manage Rook clusters on Kubernetes. Rook is a distributed blob storage system.

Sources

• Kubernetes Controller vs Kubernetes Operator?
• CoreOs - Operators
• GitHub coreos/vault-operator