How do I set DNS records for Kubernetes with a load balancer?

I am using Helm to create a Kubernetes deployment. In front of this, there is a load balancer and an ingress server - see below for an abridged version of helm status auth

==> v1/Service
NAME               TYPE          CLUSTER-IP      EXTERNAL-IP   PORT(S)       AGE
auth-mongodb       ClusterIP     10.245.186.209  <none>        27017/TCP     74s
auth-redis-master  ClusterIP     10.245.34.39    <none>        6379/TCP      74s
auth-redis-slave   ClusterIP     10.245.213.27   <none>        6379/TCP      74s
auth               LoadBalancer  10.245.82.177   46.101.65.69  80:32645/TCP  74s

==> v1beta1/Ingress
NAME  HOSTS                                  ADDRESS  PORTS  AGE
auth  auth.feature-deploy.example.com  80       74s

I’m happy enough with all this and it works great on DO. The only thing I can’t work out is how to update the DNS A record.

The domain name is managed on the DO control panel. If I manually set auth.feature-deploy.example.com and point to the load balancer, it all works fine. However, if I destroy/update the deployment, I’ll need to do this again manually.

Is there a way of getting Kubernetes to set a DNS A record that I’m missing, have I found an issue with the DO K8S stack or am I missing something?

Thanks

Ingress definition

# Source: auth/templates/ingress.yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: auth
  labels:
    app.kubernetes.io/name: auth
    helm.sh/chart: auth-0.1.0
    app.kubernetes.io/instance: auth
    app.kubernetes.io/managed-by: Tiller
spec:
  rules:
    - host: "auth.feature-deploy.example.com"
      http:
        paths:
          - path: /
            backend:
              serviceName: auth
              servicePort: http