How can I use my domain for google kubernetes engine deployed apps?

I am new at google kubernetes engine. So I am createing a new cluster. And deploying a sample application on this cluster. And I can access it using an ip address like 30.31.32.33/api So I want to use my domain name (mydomain.com or subdomain products.mydomain.com) for this app

1. Should I set nameserver of domain to ip address 30.31.32.33/api . Dose this ip address change if recreate the cluster?
2. If I want publish a new app on same cluster with different domain, what can I do?

You'll want to use a static IP in order to ensure that the IP does not change. There is a good tutorial on this here.

The high level steps:

1. Reserve a global static external IP address

    gcloud compute addresses create $ADDRESS_NAME \
    --global \
    --ip-version IPV4
   

2. Create the DNS A record mapping your FQDN to that IP address

3. Use the kubernetes.io/ingress.global-static-ip-name annotation in your Ingress:

    apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      name: myapp
      annotations:
        kubernetes.io/ingress.global-static-ip-name: $ADDRESS_NAME
      labels:
      app: myapp
    spec:
      rules:
      - host: "products.mydomain.com"
        http:
          paths:
            - path: /*
              pathType: ImplementationSpecific
              backend:
                service:
                  name: products-service
                  port:
                  number: 8080
   

4. If you want to publish more apps, if they are in separate namespace then just repeat steps 1-3 above for each app. If you deploy all of the apps in the same namespace, then you can create additional DNS A records for each app and point them to the same IP created in step 1 and then modify the Ingress in step 3 above:

    apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      name: myapp
      annotations:
        kubernetes.io/ingress.global-static-ip-name: $ADDRESS_NAME
      labels:
      app: myapp
    spec:
      rules:
      - host: "products.mydomain.com"
        http:
          paths:
            - path: /*
              pathType: ImplementationSpecific
              backend:
                service:
                  name: products-service
                  port:
                  number: 8080
      - host: "app2.mydomain.com"
        http:
          paths:
            - path: /*
              pathType: ImplementationSpecific
              backend:
                service:
                  name: app2-service
                  port:
                  number: 8080