Contributing to Lightning - acquia/lightning GitHub Wiki

First, you need to set up your development environment.

Note that these instructions won't work on old, unsupported branches of Lightning. At the time of this writing, that includes the 8.x-1.x and 8.x-2.x branches, which have long since reached the end of their lives.

This documentation describes how to set up Lightning (or any of its components) for development on a machine running a Unix-like operating system (e.g., Linux or macOS). We assume that:

You have Git installed in your PATH. You can confirm this by running git --version.
You have PHP 7.1 or later installed in your PATH. You can confirm this by running php --version.
You have Composer installed in your PATH. You can confirm this by running composer --version. You should also have Composer's global binary directory (usually $HOME/.composer/vendor/bin) in your PATH.
You will need drush/drush-launcher globally installed. To confirm this, run drush --version. If the command is not found, run composer global require drush/drush-launcher.
You will also need a database server installed. Lightning uses SQLite by default for development, since it is the most lightweight option supported by Drupal core.

Now, get your Lightning code base set up:

Clone the git repository, e.g. git clone [email protected]:acquia/lightning.git
Enter the repository and run composer install to install all dependencies.
Install Lightning and all necessary components by running ./install-drupal.sh. By default, this will try to install a SQLite database file called db.sqlite in the docroot directory. You can override this by passing a DB_URL environment variable to install-drupal.sh, containing the Drush-compatible URL of the database you want to use. For example:

DB_URL=mysql://user:password@server/drupal ./install-drupal.sh

Run the web server. The quickest option is to use PHP's built-in server: drush runserver 8080
You should now be able to access your Lightning site at http://localhost:8080.