I'm trying to create a mTLS mesh inside GKE with the Istio beta but can't communicate with the service discovery setup we currently use without the mesh.

We use Consul for service discovery as well as a keystore and package the consul executable inside our microservices to register with the main consul service in the GKE cluster. The microservices can then use the local consul client to gather items from the keystore easily. After setting up the istio mesh in a brand new cluster, and enabling auto sidecar injection, I was seeing the microservice having issues with communication. My understanding is that a k8s service needs to point to the pod for the Istio mesh to work, but we also use the service for microservices to find our main consul pod anyway (we actually use a cluster of 3, but for this test I'm only running a single pod). Here is the service yaml:

apiVersion: v1
kind: Service
metadata:
  labels:
    name: consul
  name: consul
spec:
  ports:
    - name: consul-8400
      port: 8400
      targetPort: 8400
    - name: consul-8500
      port: 8500
      targetPort: 8500
    - name: consul-8600
      port: 8600
      targetPort: 8600
    - name: consul-8300
      port: 8300
      targetPort: 8300
    - name: consul-8301
      port: 8301
      targetPort: 8301
    - name: consul-8301-udp
      port: 8301
      targetPort: 8301
      protocol: UDP
    - name: consul-8302
      port: 8302
      targetPort: 8302
  selector:
    name: consul
  type: NodePort

I also tested creating a similar service with the same ports pointing back to the microservice as well. I don't know what I'm missing because it's still not getting through to consul...