I've been able to get Craft to run on Google App Engine (GAE), but not Google Cloud as of yet.
The error message I'm seeing in the browser is:
/app/craftcms/storage/runtime isn't writable by PHP. Please fix that.
I encountered this error when deploying to GAE and the solution was to have the Dockerfile run a shell script that
chmod 755 -R ./storage. This approach does not work for Cloud Run as I still see the same message in the browser despite running the same script.
I know that Cloud Run is stateless, but we don't need to run admin functions while it's deployed to Cloud Run, so I can't see this being an issue. Has anyone else successfully deployed to Cloud Run?