Kubernetes will automatically manage your cluster to match the desired state. Fault-tolerant and distributed, etcd is designed to be the ultimate source of truth about your cluster. The desired state of a Kubernetes cluster defines which applications or other workloads should be running, along with which container images they use, which resources should be made available to them, and other configuration details.Ĭonfiguration data and information about the state of the cluster lives in etcd, a key-value store database. Kubernetes uses a controller to analyze the difference between the new defined state and the actual state in the cluster. Once an object has been created and defined, Kubernetes works to make sure that the object always exists.Ĭontrollers actively manage the state of Kubernetes objects and work to make changes that move the cluster from its current state to the desired state.ĭevelopers or sysadmins specify the defined state using the YAML or JSON files they submit to the Kubernetes API.

Kubernetes objects represent the state of a cluster and tell Kubernetes what you want the workload to look like. Kubernetes works based on defined state and actual state. This quick Kubernetes tutorial shows you how to create a cluster and deploy an application. It's how the users, external components, and parts of your cluster all communicate with each other. The Kubernetes API is the interface used to manage, create, and configure Kubernetes clusters. The API server determines if a request is valid and then processes it. The Kubernetes API (application programming interface) is the front end of the Kubernetes control plane and is how users interact with their Kubernetes cluster. Each node runs pods, which are made up of containers.

Each node is its own Linux® environment, and could be either a physical or virtual machine.

You can visualize a Kubernetes cluster as two parts: the control plane and the compute machines, or nodes. Kubernetes architecture divides a cluster into components that work together to maintain the cluster's defined state.Ī Kubernetes cluster is a set of node machines for running containerized applications. Kubernetes gives you the platform to schedule and run containers on clusters of physical or virtual machines.