Kubernetes

What is Kubernetes?

Kubernetes is an open source container orchestration engine for automating deployment, scaling, and management of containerized applications.

5 Reasons of using Kubernetes

• Flexible
• Reduce development and release time frames
• Cost friendly
• Increase availability and scalability of software
• Cloud migration paths

Kubernetes components

API Server

Provides an API that serves as the front end of a Kubernetes control plane. It is responsible for handling external and internal requests—determining whether a request is valid and then processing it.

etcd

A key-value database that contains data about your cluster state and configuration. Etcd is fault tolerant and distributed.

scheduler 

This component is responsible for scheduling pods on specific nodes according to automated workflows and user defined conditions, which can include resource requests, concerns like affinity and taints or tolerations, priority, persistent volumes , and more.

controller-manager 

The controller manager is responsible for several controllers that handle various automated activities at the cluster or pod level, including replication controller, namespace controller, service accounts controller, deployment, statefulset, and daemonset.

proxy 

All compute nodes contain kube-proxy, a network proxy that facilitates Kubernetes networking services. It handles all network communications outside and inside the cluster, forwarding traffic or replying on the packet filtering layer of the operating system.

Networking driver

Networking driver enables containers to communicate with hosts or other containers. It is often achieved by using the container networking interface (CNI), which is a joint initiative by Kubernetes, Apache Mesos, Cloud Foundry, Red Hat OpenShift, and others.