This is Lesson 4 of Tutorial: Deploying an Application in Drupal 9.
 

In this lesson we will:

• Update production database to reflect code changes

Lesson Goal

Perform application updates after new code has been deployed.

In order to complete this lesson you will need:

• Command line access to an Acquia Cloud Platform subscription
• Drupal application that is deployed to Acquia Cloud Platform

Lesson

Configuration and database updates

At this point, the code for your new release is on your production server(s). However, your database has not been updated in any way.

Database updates

A typical code release will require the following database-related actions to be performed:

• Update hooks provided by contributed modules should be executed. This is easily accomplished with:
  copy

  drush updatedb

• Changes to exported configuration files should be imported. Depending on your configuration management strategy, this may require:
  copy

  drush config-import

  or
  copy

  drush features-revert-all

• Your caches should be rebuilt. This will allow changes to Twig templates, CSS, JavaScript, and various other cached data to be registered. This can be accomplished with:
  copy

  drush cache-rebuild

Depending on the changes that your release contains, these commands may need to be run in a specific order or even multiple times. The consequences of running these commands incorrectly can be subtle and complex.

Acquia Cloud Hooks

Important

When creating a new Acquia Cloud CD environment, the post-code-deploy hook is not run, and this hook must be run twice for its changes to take effect. For more information, see this known issue.

Acquia Cloud Hooks provide a mechanism for executing a script when a particular action is performed. For releases, the post-code-update and post-code-deploy cloud hooks are relevant. These will allow a custom script to be executed each time that a new tag is deployed to your production environment.

To implement a cloud hook, you must create an executable bash script and place it in a specific location in your codebase.
 

Congratulations, you've successfully deployed a Drupal application to a production environment following Drupal best practices!