I am running a number of Cloud Run services which all have VPC access via a VPC connector and setting all egress to run through this connector. I have an ILB set up which points to a Regional Backend Service with Serverless Network Endpoint Group type. When you select this type you are unable to choose the protocol for the service (HTTP, HTTPS, HTTP/2)
The receiving Cloud Run is set to ingress unauthenticated and to allow internal/cloud-load-balancing.
When my client tries to send messages to my server via an address that resolves to the ILB it fails with a very non-descript error: rpc error: code = Unknown desc =.
I have tried using the direct cloud run url as opposed to going via my ILB and this does work. I would prefer to use my internal DNS though if possible.
The
rpc error: code = Unknown desc =is indicative of the ILB encountering difficulty in routing the traffic. Ensure that your routing rules include an additional host entry specifying yourdomain:port.