I see guides like this where setting up an Nginx Ingress (with ssl) requires you enter the host, i.e. echo1.example.com. I don't understand how you would be able to use the host specified if you didn't have the IP address (in your DNS, how would you know where to piont echo.example.com?).

When I set up an ingress like this, echo.example.com would show up as the ingress ADDRESS, so I don't know the IP. If I don't specify it, the ADDRESS is just empty. With this, how am I suppose to know what IP I'm suppose to point my domain name?

I'm running on GKE.

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: echo-ingress
  annotations:  
    kubernetes.io/ingress.class: nginx
    certmanager.k8s.io/cluster-issuer: letsencrypt-staging
spec:
  tls:
  - hosts:
    - echo1.example.com
    - echo2.example.com
    secretName: letsencrypt-staging
  rules:
  - host: echo1.example.com
    http:
      paths:
      - backend:
          serviceName: echo1
          servicePort: 80
  - host: echo2.example.com
    http:
      paths:
      - backend:
          serviceName: echo2
          servicePort: 80