Cloud Identity-Aware Proxy
Identity-Aware Proxy (IAP) lets you manage access to applications running in App Engine standard environment, App Engine flexible environment, Compute Engine, and GKE. IAP establishes a central authorization layer for applications accessed by HTTPS, so you can adopt an application-level access control model instead of using network-level firewalls. When you turn on IAP, you must also use signed headers to secure your app.