How do the components of Kubernetes work?

Kubernetes (k8s) is an open-source container orchestration platform designed to automate the deployment, scaling, and management of containerized applications. It consists of multiple components, each with unique functions and mechanisms.

Below are some key Kubernetes components and how they operate:

1. Master component: The master component is made up of multiple child components, including kube-apiserver, kube-controller-manager, and kube-scheduler. They collaborate to coordinate and manage the various nodes in the cluster.

1. kube-apiserver: It offers an interface for the Kubernetes API, which is used to receive and process requests from users or other components.
2. Kube-controller-manager is responsible for running various controllers to monitor the cluster’s status and perform operations based on desired configurations and rules to maintain the cluster’s desired state.
3. The kube-scheduler is responsible for selecting the appropriate node for deploying newly created containers, taking into account the availability and workload of node resources.

1. Node components: Node components run on each node and include kubelet, kube-proxy, and container runtimes like Docker.

1. The kubelet communicates with the Master component and is responsible for managing and monitoring containers on the node. It receives Pod specifications sent by the kube-apiserver and ensures that the containers in the Pod are running correctly on the node.
2. Kube-proxy is responsible for providing network proxy and load balancing functionality for services, ensuring service accessibility by creating network rules for services.
3. Container runtime: responsible for running containers on nodes, such as Docker, containerd, etc.

1. etcd is a distributed key-value store system used to store configuration data and status information of the cluster. All Master and Node components utilize etcd to share and synchronize cluster information.
2. Other optional components in addition to the core components mentioned above are provided by Kubernetes, such as Ingress Controller, Persistent Volume, and Storage Class, to offer additional functionalities like load balancing and persistent storage.

In essence, Kubernetes components work together to provide automated deployment, scalability, and management of containers. The Master component manages the state and configuration of the entire cluster, the Node component runs and manages containers on nodes, and etcd is used for sharing and synchronizing cluster information.