Google Cloud Run 404 Error on internal traffic between services

Question

I am currently trying to connect two Google Cloud Run services. Both use the default service account, are deployed in europe-west1 , require no IAM-authentication and only accept internal traffic (and load balancing traffic). I have following architecture

Load Balancer
    |
    ` /service -------> service-0 -------> service-1

service-0 acts as reverse proxy that adds some authentication headers and is connected to service-1 via its https://<service-1>.run.app url. Whenever I try to connect to service-1 from the Internet (via Load Balancer and service-0 ) I get a 404 error from the ingress sitting in front of service-1 . I can verify that service-0 forwards the request correctly.

However when I expose service-1 to the internet, I reach the service without any problems.

This post Google Load Balancer to Cloud Run giving 404 suggests that it is an issue with europe-west1 region, but I cannot simply switch the region. Any help would be appreciated.

Answer 1

After some time now, it turned out to be a Problem with Google Cloud Run in europe-west1. We contacted support and switched to GKE.