Goal

Dynamically access the port a service is listening on, via Railway reference variable.

Context

• Both services are in the same environment/project

• Both are listening on IPV6 host (::)

• Both services are listening on the default PORT env var made available to them at runtime (8080)

Status

I've tried a reference variable as mentioned in this doc: https://docs.railway.com/guides/private-networking#using-reference-variables

It looks something like: http://${{service.RAILWAY_PRIVATE_DOMAIN}}:${{service.PORT}}

When logging this variable to console, the domain comes through, but the port is empty. My thinking was that the PORT variable used above would always be set to that which service is listening on - or at least, the one Railway automatically passes to the service at runtime.

I imagine that if I manually set a service variable, like PORT=8080, then this would work. But I was sort of hoping to let Railway do its thing and let these get set dynamically.

Apologies if this is made clear in the docs - it's possible I'm misunderstanding it.