Enhance conditional config sync directory logic

web/sites/default/settings.php

@@ -19,10 +19,25 @@
 /**
  * Place the config directory outside of the Drupal root.
  */
-$config_directories = array(
-  CONFIG_SYNC_DIRECTORY => $_ENV['HOME'] . '/files/private/config',
-);
-
+if(!empty($_ENV['FILEMOUNT'])) {
+  error_log("Config sync dir: _ENV[FILEMOUNT] exists, using it.");
+  $config_directories = array(
+    CONFIG_SYNC_DIRECTORY => DRUPAL_ROOT . '/' . $_ENV['FILEMOUNT'] . '/private/config',
+  );
+}
+else if (is_dir($_ENV['HOME'] . '/files/private/config')) {
+  error_log("Config sync dir: _ENV[HOME]/files/private/config exists, using this.");
+  $config_directories = array(
+    CONFIG_SYNC_DIRECTORY => $_ENV['HOME'] . '/files/private/config',
+  );
+}
+else {
+  error_log("Config sync dir: fell through to default.");
+  $config_directories = array(
+    CONFIG_SYNC_DIRECTORY => DRUPAL_ROOT . '/sites/default/files/private/config',
+  );
+}
+error_log("Config sync dir: " . $config_directories[CONFIG_SYNC_DIRECTORY]);
 /**
  * If there is a local settings file, then include it
  */