Creating a site-wide playbook, nesting, and using include statements

As a best practice, we will create a top-level file, which will contain the blueprint of our complete infrastructure. Technically, we can include everything that we need to configure inside just one file. However, that would have two problems:

• It would quickly get out of control as we start adding tasks, variables, and handlers to this single file. It would be a nightmare to maintain such code.
• It would also be difficult to reuse and share such code. One of the advantages of using a tool such as Ansible is its ability to separate data from code. Data is organization-specific, and code is generic. This generic code can then be shared with others. However, if you write everything in a single file, it would be impossible to do so.

To avoid this problem, we will start organizing our code in a modular fashion, as follows:

• We will create roles for each of the applications that we need to configure. In this case, it is Nginx
• Our web...