Mastering Drupal 8 assumes that you are already running a local AMP stack and are familiar with installing Drupal using the standard means of downloading, setting up a database, configuring a local host, and completing the browser-based install. In Chapter 1, Developer Workflow, we walked through quickly installing Drupal using Composer, Drush, and Drupal Console. Ensure that you have a working AMP stack and are comfortable working within the command-line interface using a Terminal window before continuing.

By default, Drupal has two interfaces we can work with. The first is what any visitor to our site will see, consisting of content and blocks displayed in various regions on the page. This is often referred to as the anonymous user's view:

The second interface, known as the administrator interface, requires us to be logged in to a Drupal instance. We can log in by clicking on the login link or by navigating to /user/login and entering the user credentials that were created when Drupal was first installed:

Once logged in we are considered to be authenticated and, since we are logged in as User one, which is the Super User, we are also considered to be an administrator and are presented with an Admin toolbar.

The Admin toolbar itself is separated into three different functional areas: Manage, Shortcuts, and admin. Each of these sections organize...

Changes to the Site name, Email address, default front page, and error pages can all be configured under the Basic site settings of Drupal. This section of Drupal can often be overlooked since both the Site name and Email address fields are configured for us during installation. However, the Basic site settings control more than just these two fields, and it is important to know where they are located and how to modify these values using all the tools made available to us.

We can navigate to the Basic site settings by directly entering the URL of /admin/config/system/site-information, or by using the Admin toolbar and clicking on Manage | Configuration | Basic site settings:

The Basic site settings for Drupal contain three subsections:

• SITE DETAILS
• FRONT PAGE
• ERROR PAGES

Managing configuration within Drupal does not always involve changing settings within the administrative panels of a specific section. In fact, Drupal also allows various settings to be configured within the settings.php file. Configuration settings within the settings.php file act as global overrides to those in the database. Some settings, as we will see, can only be set or modified from the settings.php file.

The settings.php file can be located within the /sites/default folder of a Drupal installation.

Keep in mind that the file permissions are set to read only; so, it is important to temporarily modify the permissions to be writeable before making any changes.

Once we have made the settings.php file writeable, we can open it within our favorite editor and locate the Configuration overrides section:

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Reading through the Configuration overrides...

Drush allows us to perform a multitude of tasks using the command line to interact with Drupal. A handful of commands that allow us to manage configuration include drush config-list, drush config-get, and drush config-set. Let's look at how we would use each of these to manage Basic site settings.

If we open a Terminal window and navigate to our Drupal instance, we can enter the following command to see a list of variables:

    drush config-list

We can also retrieve...