Earlier this week, I wrote about using Firebase Authentcation, Cloud Endpoints and gRPC (1of2). Since then, I learned some more and added a gRPC interceptor to implement basic authorization for the service. ESPv2 --allow-unauthenticated The Cloud Enpoints (ESPv2) proxy must be run as --allow-unauthenticated on Cloud Run to ensure that requests make it to the proxy where the request is authenticated and only authenticated requests make it on to the backend service.

I’m building a service that requires user authentication. The primary endpoint is a gRPC-based service. I would like to consider using certificate-based auth but this feels… challenging. Instead, I have been aware of, but never used, Firebase Authentication and was interested to see that Cloud Endpoints includes Firebase Authentication as one of its supported auth mechanisms. Curiosity piqued, I confirmed that gRPC supports Google token-based authentication. The following is a summary of what I did but I’ll leave the extensive documentation to Google, (Google’s) Firebase and gRPC, all of which, in this case, provide really good explanations.