KUBERNETES

Kubernetes is a portable, extensible, open-source platform for managing containerized workloads and services, which facilitates both declarative configuration and automation. It has a large, rapidly growing ecosystem. Kubernetes services, support and tools are widely available.

The name Kubernetes originates from Greek, meaning helmsman or pilot. Google open-sourced the Kubernetes project in 2014.

Traditional deployment era: Early on, organizations ran applications on physical servers. There was no way to define resource boundaries for applications in a physical server and this caused resource allocation issues. For example, if multiple applications run on a physical server, there can be instances where one application would take up most of the resources and as a result the other applications would underperform. A solution for this would be to run each application on a different physical server. But this did not scale as resources were underutilized and it was expensive for organizations to maintain many physical servers.

Virtualized deployment era: Virtualization was introduced as a solution for traditional deployment. It allows running multiple Virtual Machines on a single physical server’s CPU, which allows applications to be isolated between virtual machines. This provides a level of security as the information of one application cannot be freely accessed by another application.

Container deployment era: Containers are similar to virtual machines, but they have relaxed isolation properties to share the operating system among the applications. Similar to a virtual machine, a container has its own file system, CPU, memory, process space and more. As they are decoupled from the underlying infrastructure, they are portable across clouds and operating system distributions.

Containers are a good way to bundle and run your applications. In a production environment, you need to manage the containers that run the applications and ensure that there is no downtime. This is where Kubernetes enters the equation. Kubernetes provides you with a framework to run distributed systems resiliently. It takes care of scaling and failover for your application and provides deployment patterns and more.

• Kubernetes can expose a container using the DNS name or using their own IP address. If traffic to a container is high, Kubernetes is able to load balance and distribute the network traffic so that the deployment is stable.
• Kubernetes allows you to automatically mount a storage system of your choice, such as local storages, public cloud providers and more.
• You can describe the desired state for your deployed containers using Kubernetes and it can change the actual state to the desired state at a controlled rate. For example, you can automate Kubernetes to create new containers for your deployment, remove existing containers and adopt all their resources to the new container.
• Kubernetes restarts containers that fail, replaces containers, kills containers that do not respond to your user-defined health check.