External DNS + Ingress Nginx + AWS ALB

Question

I got the following setup:

Ingress-Nginx-Controller (serviceType "NodePort")

AWS-Load-Balancer-Controller

External-DNS

I am exposing the Ingress-Nginx-Controller via an Ingress, backed by the AWS Load Balancer Controller both public and private. I chose this route, since it was pretty easy to limit the inbound CIDRs. And nginx ingress cannot create an ALB but only Classic LB or NLB.

kubectl -n ingress-nginx get ing

NAME CLASS  HOSTS  ADDRESS  PORTS  AGE
alb-ingress-connect-nginx  alb  *  xxxx.region.elb.amazonaws.com  80 2d8h

This ingress forwards all traffic to my nginx controller.

The service looks like

kubectl -n ingress-nginx get svc
NAME  TYPE CLUSTER-IP  EXTERNAL-IP  PORT(S) AGE
ingress-nginx-controller  NodePort a.b.c.d

I am trying to automatically setup dns records for my deployment via External-DNS. Therefore, I am creating an ingress for my deployment with ingress-class nginx and specified hostname.

Creating the records works, however it uses the IP of my ingress-nginx-controller service (a.b.c.d) instead of the loadbalancer's address.

Now my question: Is it possible to for external-dns to lookup the address of the nginx ingress or does this work only if the Nginx is exposed as service of type "LoadBalancer"?

Thanks for any help

Answer 1

I am able to figure this out by using --publish-status-address in nginx controller to point to ALB. If you are using 2 ALBs (public and private), you need to create 2 nginx controllers with --publish-status-address points to each ALB. Also, remember to disable --publish-service parameter. And use different electionID for each controller if you have installed nginx controllers using Helm