Book Image

Getting Started with Containerization

By : Dr. Gabriel N. Schenker, Hideto Saito, Hui-Chuan Chloe Lee, Ke-Jou Carol Hsu
Book Image

Getting Started with Containerization

By: Dr. Gabriel N. Schenker, Hideto Saito, Hui-Chuan Chloe Lee, Ke-Jou Carol Hsu

Overview of this book

Kubernetes is an open source orchestration platform for managing containers in a cluster environment. This Learning Path introduces you to the world of containerization, in addition to providing you with an overview of Docker fundamentals. As you progress, you will be able to understand how Kubernetes works with containers. Starting with creating Kubernetes clusters and running applications with proper authentication and authorization, you'll learn how to create high-availability Kubernetes clusters on Amazon Web Services (AWS), and also learn how to use kubeconfig to manage different clusters. Whether it is learning about Docker containers and Docker Compose, or building a continuous delivery pipeline for your application, this Learning Path will equip you with all the right tools and techniques to get started with containerization. By the end of this Learning Path, you will have gained hands-on experience of working with Docker containers and orchestrators, including SwarmKit and Kubernetes. This Learning Path includes content from the following Packt products: • Kubernetes Cookbook - Second Edition by Hideto Saito, Hui-Chuan Chloe Lee, and Ke-Jou Carol Hsu • Learn Docker - Fundamentals of Docker 18.x by Gabriel N. Schenker
Table of Contents (25 chapters)
Title Page
Copyright
About Packt
Contributors
Preface
Index

Managing Pods with ReplicaSets 


A ReplicaSet is a term for API objects in Kubernetes that refer to Pod replicas. The idea is to be able to control a set of Pods' behaviors. The ReplicaSet ensures that the Pods, in the amount of a user-specified number, are running all the time. If some Pods in the ReplicaSet crash and terminate, the system will recreate Pods with the original configurations on healthy nodes automatically, and keep a certain number of processes continuously running. While changing the size of set, users can scale the application out or down easily. According to this feature, no matter whether you need replicas of Pods or not, you can always rely on ReplicaSet for auto-recovery and scalability. In this recipe, you're going to learn how to manage your Pods with ReplicaSet:

ReplicaSet and their Pods on two nodes

The ReplicaSet usually handles a tier of applications. As you can see in the preceding diagram, we launch a ReplicaSet with three Pod replicas. Some mechanism details...