Documentation restructuring

docs/intermediate/add-custom-environment-variables.rst

@@ -0,0 +1,51 @@
+.. _add_custom_environment_variables:
+
+********************************
+Add custom environment variables
+********************************
+
+If your application requires a variable to determine if it is run under development or
+production, you can easily add it and make PHP aware of it.
+
+
+**Table of Contents**
+
+.. contents:: :local:
+
+
+Add custom environment variables
+================================
+
+This is fairly simple. Any variable inside the ``.env`` file is considered an environment variable
+and automatically known to PHP.
+
+If you for example require a variable ``APPLICATION_ENV``, with a value of ``production``, you
+would add the following to the ``.env`` file:
+
+.. code-block:: bash
+   :caption: .env
+   :emphasize-lines: 1
+
+   APPLICATION_ENV=production
+
+You need to restart the Devilbox for the changes to take effect.
+
+.. note::
+   There is already a proposed section inside the ``.env`` file at the very bottom
+   to add you custom variables to differentiate them from the Devilbox required variables.
+
+
+Use custom environment variables
+================================
+
+Accessing the above defined environment variable on the PHP side is also fairly simple.
+You can use the PHP's built-in function ``getenv`` to obtain the value:
+
+.. code-block:: php
+   :caption: index.php
+   :emphasize-lines: 3
+
+   <?php
+   // Example use of getenv()
+   echo getenv('APPLICATION_ENV');
+   ?>