Book Image

Modern DevOps Practices

By : Gaurav Agarwal
Book Image

Modern DevOps Practices

By: Gaurav Agarwal

Overview of this book

Containers have entirely changed how developers and end-users see applications as a whole. With this book, you'll learn all about containers, their architecture and benefits, and how to implement them within your development lifecycle. You'll discover how you can transition from the traditional world of virtual machines and adopt modern ways of using DevOps to ship a package of software continuously. Starting with a quick refresher on the core concepts of containers, you'll move on to study the architectural concepts to implement modern ways of application development. You'll cover topics around Docker, Kubernetes, Ansible, Terraform, Packer, and other similar tools that will help you to build a base. As you advance, the book covers the core elements of cloud integration (AWS ECS, GKE, and other CaaS services), continuous integration, and continuous delivery (GitHub actions, Jenkins, and Spinnaker) to help you understand the essence of container management and delivery. The later sections of the book will take you through container pipeline security and GitOps (Flux CD and Terraform). By the end of this DevOps book, you'll have learned best practices for automating your development lifecycle and making the most of containers, infrastructure automation, and CaaS, and be ready to develop applications using modern tools and techniques.
Table of Contents (19 chapters)
1
Section 1: Container Fundamentals and Best Practices
7
Section 2: Delivering Containers
15
Section 3: Modern DevOps with GitOps

Understanding Kubernetes pods

Kubernetes pods form the basic building block of a Kubernetes application. A pod contains one or more containers, and all containers within a pod are always scheduled in the same host. Usually, there is a single container within a pod, but there are use cases where you might want to schedule multiple containers in a single pod.

It takes a while to digest why Kubernetes started with the pod's concept in the first place instead of using containers, but there are reasons for that, and you will appreciate this as you gain more experience with the tool. For now, let's look at a simple example of a pod and how to schedule it in Kubernetes.

Running a pod

We will start by running an NGINX container in a pod using simple imperative commands. We will then look at how we can do it in a declarative fashion.

To access the resources for this section, cd into the following:

$ cd ~/modern-devops/ch4/pod/

To run a pod with a single NGINX container...