Rewrite Authority in Envoy Filter


So in this scenario, I want to be able to rewrite the Host header when a request comes in so that it routes to a VirtualService listening on the host that I’ve rewritten. I have an Envoy Filter with the following code in it.

serviceName = headers:get("x-service-name")
headers:add("X-Forwarded-Host", headers:get(":authority"))
headers:replace("host", serviceName .. ".company.local")
headers:replace(":authority", serviceName.. ".company.local")

And a VirtualService that has a setup similar to the following

- my-gateway

However, if I try to make a call to the service with something along the lines of the following, I get a 404 response from Istio.

curl -H "X-Service-Name: my-service"

The host I’m trying to route to ( doesn’t actually exist, and DNS resolution wouldn’t provide anything, I was sort of just hoping that Istio would see the host in the VS and direct traffic that way, is that not the case?

If DNS does need to resolve, would I be able to use a ServiceEntry with a host that forwards traffic to the right Kubernetes service or something, so that I don’t need to create a real DNS entry?