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Fix Broken Links in Drupal

Learn how to update Drupal site links so the URL references the correct file path and domain name.

When editing content, links can be inserted that don't reflect the site's domain name. For example, an image URL appears as instead of

The link may work at first, but will eventually break when your application container’s IP address changes due to the nature of Pantheon’s cloud-based infrastructure.

Drupal Configure $base_url

Sometimes, the $base_url, if not explicitly set, is the URL from which the asset was loaded. If a module cache is populated on a Drush Cron run from the CLI, this can be the app-container IP which is dynamic and will ultimately become a broken link. The current resolution is to set $base_url per environment in settings.php and clear caches. There are some notes about this in the Pathologic documentation.

If you look through the Media module issue queue, you’ll see that other users have experienced the same or very similar issues with WYSIWYG-inserted images having their base URLs cached. The IP address is coming from a cached reference to the image’s location as generated by the media filter. Dave Reid (the Media module maintainer) has explained it in this comment.

The recommended solution is setting the $base_url in your settings.php. This prevents the IP:PORT address from being stored in URLs. Check that you're using the latest version of the module(s).

Here is an example of a code snippet to set the $base_url per environment:

if (isset($_ENV['PANTHEON_ENVIRONMENT']) && php_sapi_name() != 'cli') {
  // Redirect to https://$primary_domain/ in the Live environment
  if ($_ENV['PANTHEON_ENVIRONMENT'] === 'live') {
    // Replace with your registered domain name.
    $primary_domain = '';
  else {
    // Redirect to HTTPS on every Pantheon environment.
    $primary_domain = $_SERVER['HTTP_HOST'];
  $base_url = 'https://'. $primary_domain;
  if ($_SERVER['HTTP_HOST'] != $primary_domain
      || !isset($_SERVER['HTTP_USER_AGENT_HTTPS'])
      || $_SERVER['HTTP_USER_AGENT_HTTPS'] != 'ON' ) {

    // Name transaction "redirect" in New Relic for improved reporting (optional).
    if (extension_loaded('newrelic')) {

    header('HTTP/1.0 301 Moved Permanently');
    header('Location: '. $base_url . $_SERVER['REQUEST_URI']);

Clear cache after deploying this code change. All cached IP:PORT references will be wiped out, and repopulated with the correct base URL in the future.

More Resources

Private Paths

Symlinks and Assumed Write Access