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

Ansible tasks and modules

Ansible tasks form the basic building block of running Ansible commands. Ansible tasks are structured in the following format:

$ ansible <options> <inventory>

Ansible modules are a reusable unit of code that does a particular thing very well, such as running a shell command, and creating and managing users. You can use Ansible modules with Ansible tasks to manage the configuration within the managed nodes. For example, the following command will run the uname command on each server we are managing:

$ ansible -m shell -a "uname" all
db | CHANGED | rc=0 >>
Linux
web | CHANGED | rc=0 >>
Linux

So we get a reply from the db server and the web server, each providing a return code, 0, and an output, Linux. If you look at the command, you will see that we have provided the following flags:

  • -m: The name of the module (shell module here)
  • -a: The parameters to the module (uname in this case)

The command...