Kubernetes

Kubernetes is a system for running containers across a fleet of machines without placing each one by hand. You write down what you want, say three copies of this web server with this much memory, reachable at this address, and Kubernetes works out which machines to put them on. Its core idea is a reconcile loop: controllers keep comparing the desired state you declared with what’s actually running, and act to close the gap. If a machine dies and takes a copy with it, Kubernetes notices there are now two and starts a third elsewhere. The same loop drives rolling updates, scaling and restarts, which is why it has become the default way large companies run services.