Introduction

What good is an application unless it is being used? In today's day and age—when DevOps became the way of doing software development, when Cloud is the king, and when building Microservices is considered as the thing to do—a lot of attention is being focused on how the applications get packaged, distributed, and deployed in their designated environments.

The Twelve-Factor App methodology has played an instrumental role in defining how a modern Software as a Service (SaaS) application is supposed to be built and deployed. One of the key principles is the separation of environmental configuration definitions from the application and storage of this in the environments. They also favor the isolation and bundling of the dependencies, development versus production parity, and ease of deployment and disposability of the applications, among others.

Note

The Twelve-Factor App methodology can be found at http://12factor.net/.

The DevOps model also encourages us to have complete ownership...