Book Image

Practical DevOps - Second Edition

By : joakim verona
Book Image

Practical DevOps - Second Edition

By: joakim verona

Overview of this book

DevOps is a practical field that focuses on delivering business value as efficiently as possible. DevOps encompasses all code workflows from testing environments to production environments. It stresses cooperation between different roles, and how they can work together more closely, as the roots of the word imply—Development and Operations. Practical DevOps begins with a quick refresher on DevOps and continuous delivery and quickly moves on to show you how DevOps affects software architectures. You'll create a sample enterprise Java application that you’'ll continue to work with through the remaining chapters. Following this, you will explore various code storage and build server options. You will then learn how to test your code with a few tools and deploy your test successfully. In addition to this, you will also see how to monitor code for any anomalies and make sure that it runs as expected. Finally, you will discover how to handle logs and keep track of the issues that affect different processes. By the end of the book, you will be familiar with all the tools needed to deploy, integrate, and deliver efficiently with DevOps.
Table of Contents (12 chapters)

Salt versus Ansible versus Puppet execution models

While the configuration systems we explored in this chapter share a fair number of similarities, they differ a lot in the way code is executed on the client nodes:

  • With Puppet, a Puppet agent registers with the Puppet master and opens a communication channel to retrieve commands. This process is repeated periodically, normally every 30 minutes.
30 minutes isn't fast. You can, of course, configure a lower value for the time interval required for the next run. At any rate, Puppet essentially uses a pull model. Clients must check in to know whether changes are available.
  • Ansible pushes changes over SSH when desired. This is a push model.
  • Salt uses a push model, but with a different implementation. It employs a ZeroMQ messaging server that the clients connect to and listen for notifications about changes. This works a bit...