- API Server is a core of the Kubernetes control plane.
- The API Server exposes an HTTP API that lets end users, different parts of your cluster and external components communicate with one another.
- API Objects in Kubernetes:
- Pods
- Namespaces
- ConfigMaps
- Events
- The Kubernetes API lets you query and manipulate the state of API objects in Kubernetes.
- Operations:
- Most of the operations in Kubernetes is performed through kubectl or kubeadm.
- This in turn use the API.
- However, you can also access the API directly using REST calls.
- Clint Libraries:
- If you want to use Kubernetes REST API (API Server), you do not need to implement the API calls and request/response by yourself.
- You can use the client library for the programming language you are using.
- Client libraries often handle common tasks such as authentication for you.
- Most client libraries can discover and use the Kubernetes Service Account to authenticate if the API client is running inside the Kubernetes cluster
- Persistence:
- Kubernetes stores the serialized state of objects by writing them into etcd.