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

Designing for reusability

Ansible provides variables for turning Ansible playbooks into reusable templates. You can substitute variables in the right places using Jinja2 markup, which we've already used in the last playbook. Let's now look at Ansible variables, their types, and how to use them.

Ansible variables

Ansible variables, like any other variables, are used to manage differences between managed nodes. You can use a similar playbook for multiple servers, but sometimes there are some differences in configuration. Ansible variables help you template your playbooks so that you can reuse them for a variety of similar systems. There are multiple places where you can define your variables:

  • Within the Ansible playbook within the vars section
  • In your inventory
  • In reusable files or roles
  • Passing variables through the command line
  • Registering variables by assigning the return values of a task

Ansible variable names can include letters, numbers...