etcd

• A distributed key-value data store which stores the state of the system and the objects

• Use Raft protocol to coordinate the data access in distributed setup

• You can influence the way the API Server is using etcd via a number of options at start-up time. --etcd-servers List of etcd servers to connect with (scheme://ip:port)

• Kubernetes stores its objects in etcd either as a JSON string or in Protocol Buffers(“protobuf” for short) format

Flow from kubectl create -f pod.yaml to object in etcd

• Get the version from http path (e.g. v1 or v1beta1)

• Create the empty object using Scheme in the right version

• JSON or protobuf decoder converts the payload into object