I've been able to deploy an example Symfony 3 app to a Google AppEngine Flexible PHP app following the example here. I then added the CloudSQL APIs to the project and the entries in app.yaml so when I SSH into an instance, I can see the MySQL socket in /cloudsql/. I then added the Doctrine bundles to the Symfony project, setup a couple models, etc., tested locally successfully, and tried to redeploy the app to Google.
When the deploy process runs composer, it's running the symfony-scripts entries defined in composer.json. Some of those routines need to access the database apparently but that's failing. I'm getting An exception occurred in driver: SQLSTATE[HY000] [2002] No such file or directory errors from the clearCache script. If I remove that entry from composer.json and retry, I get the same error from the next script.
I'm beginning to think that the socket that connects to the database may not be configured during the app deploy process. Has anyone tried to do something like this before and gotten it to work?
