Add kubernetes service dns aliases

Question

For publicly exposed Kubernetes services - type LoadBalancer - we have a dns record that points to the external ip address.

In each service we do TLS termination with a LetsEncrypt certificate that is tied to the external name. It's not allowed to add the internal name to the certificate as well.

What I would like to do is use any application in the same Kubernetes cluster connect using the external name but keep communication internal.

Is there any way to provide a dns record in the Kubernetes cluster that resolves the same name to the internal service ip address to do so?

Answer 1

For reference, you can achieve this configuring CoreDNS. Example configuration that will link from external DNS name foo.example.com to the internal IP of foo service in default namespace

    .:53 {
        errors
        log
        health
        rewrite name foo.example.com foo.default.svc.cluster.local
        kubernetes cluster.local 10.0.0.0/24
        file /etc/coredns/example.db example.org
        proxy . /etc/resolv.conf
        cache 30
    }

Thanks @Jorrit Salverda for opening the kubernetes issue with this.