title: How to share a Google Cloud SQL instance between two projects using private IP?
body: <p>I have two projects in GCP, both are running App Engine Flexible environments with Node.js. One of the projects has an Cloud SQL instance attached, running with Private IPs. I want the App Engine in the other project to be able to use this Cloud SQL instance (PostgreSQL) as well, but it's not getting a connection. </p>
  
  <ul>
  <li>All instances are running in the same region</li>
  <li>I have peered both VPCs</li>
  <li>Service Networking API is activated in both projects</li>
  <li>Service account of the project that needs to be connected has "Cloud SQL Client" rights for the project that created the SQL instance</li>
  </ul>
  
  <p>From my understanding the Cloud SQL instance lives in its own VPC that is peered by automatically created peer connections and routes to the project from which it has been created. But there does not seem to be a way to create those routes and peers for another VPC in order to connect it, right?</p>
  
  <p>Or is there another possibility to connect both projects to the same Cloud SQL?</p>