firebase - How to use the same IP address in different Google Cloud projects

Question

I'm developping an app that uses Firebase (Google Cloud) for back-end application. The project containts several Firebase Functions that are used to get data from a third party that only accept one validated fixed IP address (which I managed to do via a VPC).

My start production is soon so I felt it would be a good time now to set two different environnements, one for developpement and one for production, which would mean two different Google Cloud projects (I want to separate the databases and the functions if I add some new features) with the same IP address. Is there a way to share this setting between two different Google Cloud projects ?

Answer 1

Here my idea, even if I never tested it.

On your current project, create 2 Internet network endpoint group (INEG).

• INEG-prod that use the fully qualified url of your firebase prod environment
• INEG-dev that use the fully qualified url of your firebase dev environment

Then create a Load balancer in the project where your IP address is reserved; Create 2 backend:

• Backend-prod that use the INEG-prod
• Backend-dev that use the INEG-dev

Then the URL map

• use your /* (for example) to route the request to the backend-prod
• use dev-/* (for example) to route the request to the backend-dev

On the frontend, use your static IP, and the HTTPS protocol.

It should work (wait about 5 minutes to let the HTTPS load balancer to take into account the configuration)