Chapter 1. Introducing Kubernetes


This chapter covers

  • Understanding how software development and deployment has changed over recent years
  • Isolating applications and reducing environment differences using containers
  • Understanding how containers and Docker are used by Kubernetes
  • Making developers’ and sysadmins’ jobs easier with Kubernetes

Years ago, most software applications were big monoliths, running either as a single process or as a small number of processes spread across a handful of servers. These legacy systems are still widespread today. They have slow release cycles and are updated relatively infrequently. At the end of every release cycle, developers package up the whole system and hand it over to the ops team, who then deploys and monitors it. In case of hardware failures, the ops team manually migrates it to the remaining healthy servers.

Today, these big monolithic legacy applications are slowly being broken down into smaller, independently running components called microservices. Because microservices are decoupled from each other, they can be developed, deployed, updated, and scaled individually. This enables you to change components quickly and as often as necessary to keep up with today’s rapidly changing business requirements.

1.1. Understanding the need for a system like Kubernetes

1.1.1. Moving from monolithic apps to microservices

1.1.2. Providing a consistent environment to applications

1.1.3. Moving to continuous delivery: DevOps and NoOps

1.2. Introducing container technologies

1.2.1. Understanding what containers are

1.2.2. Introducing the Docker container platform

1.2.3. Introducing rkt—an alternative to Docker

1.3. Introducing Kubernetes

1.3.1. Understanding its origins

1.3.2. Looking at Kubernetes from the top of a mountain

1.3.3. Understanding the architecture of a Kubernetes cluster

1.3.4. Running an application in Kubernetes

1.3.5. Understanding the benefits of using Kubernetes

1.4. Summary