Allow for disabling module function through settings.php

We should probably just make the module more resilient/self-disabling when it's not actively running on Pantheon. Do you know where it's hanging?

When the module is installed locally I get a 502 Bad Gateway error from my local nginx server.

The Nginx error log has:

upstream sent too big header while reading response header from upstream, client: 10.211.55.2, server: local.mydomain.com, request: "GET / HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "local.mydomain.com"

Does that help?

I see. This is about the large Surrogate-Key header. We should avoid setting that when we're not on the Pantheon platform -- unless perhaps re-enabled in settings.php.

We use Config Split ( https://www.drupal.org/project/config_split → ) for this purpose and seems to work really well. That said, I'd love the module to know if it's running on Pantheon vs locally and adjust accordingly.