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

Kubernetes Deployments

Container application deployments within Kubernetes are done through Deployment resources. Deployment resources employ ReplicaSet resources behind the scenes, so it would be good to look at ReplicaSet resources first before we move on to understand Deployment resources.

ReplicaSet resource

ReplicaSet resources are Kubernetes resources that help you run multiple replicas of a Pod at a given time. They provide horizontal scaling for your container workloads, and it forms the basic building block of a horizontal scale set for your containers, which is a group of similar containers tied together to run as a unit.

ReplicaSet resources define the number of replicas of a Pod to run at a given time. The Kubernetes controller then tries to maintain the replicas and recreates a Pod if it goes down.

You should never use ReplicaSet resources on its own, but instead, it should act as a backend to a Deployment resource.

For the sake of understanding, however...