Ability to Inject Drupal 8 Config Values into Settings.php

[populist]

Unlike the installation process for Drupal 7, Drupal 8 requires (on behalf of CMI) that the values for the configuration directories be available to settings.php. This is typically written during installation and look like this:

$config_directories['active']['path'] = 'config_1-lRVHZQPcBvES1GZkcB4OMzcH9qHNiqTxhEj706e3U/active';
$config_directories['staging']['path'] = 'config_1-lRVHZQPcBvES1GZkcB4OMzcH9qHNiqTxhEj706e3U/staging';

Since we want to skip this step all together, we will need to figure out how to modify this write/read behavior so that Pantheon can define the $config_directories values in the same way we currently do for the $databases.

[populist]

We can switch this around to support better pathing. Possible examples could include:

/sites/default/files/config/[ENVIRONMENT]-active
/sites/default/config/staging

The reason to move these directories is to allow this configuration to be managed by git and magiced through our workflow tools.

[populist]

We will need to make sure that these do not get squashed if someone pushed up custom items in settings.php (i.e. local developers).

[populist]

Here is the logic we are using for now. Will need to be updated with correct paths which ideally would be pushed in through PRESSFLOW_SETTINGS:

// Load CMI directory config, if present.
  if (isset($_SERVER['PRESSFLOW_SETTINGS'])) {
    $config_directories = array(
      CONFIG_ACTIVE_DIRECTORY => array(
        'path' => 'config_active',
      ),
      CONFIG_STAGING_DIRECTORY => array(
        'path' => 'config_staging',
      ),
    );
  }

[populist]

This logic has been moved to settings.php for the time being

[grayside]

Found this issue while googling for https://drupal.org/node/1830816.

[populist]

Since the CMI active configuration is now in the database, we can simplify this a bit.

[populist]

I also added a quick workaround so this directory is actually sites/default/files during installation so the write-ability check passes. You will still need to make the configuration writeable to use CMI, but it wont bust install.

[populist]

As a quick note, it probably is best to have the configuration settings happen in settings.php WITHOUT a wrapper for running on Pantheon so folks who move elsewhere or have a local development setup still are able to find where their configuration lives.

[populist]

We should also add a message that describes the privacy settings of these values and consider moving it to /private so it is private + versionable on Pantheon.

[greg-1-anderson]

I would propose the following note about privacy and config paths:

IMPORTANT SECURITY NOTE:  The configuration paths set up
below are secure when running your site on Pantheon.  If you
migrate your site to another environment on the public internet, 
you should relocate these locations. See "After Installation"
at https://www.drupal.org/node/2431247

[greg-1-anderson]

Everything mentioned here has been committed.