How do I use minikube's DNS?

Question

How do I use minikube's (cluster's) DNS? I want to receive all IP addresses associated with all pods for selected headless service? I don’t want to expose it outside the cluster. I am currently creating back-end layer.

As stated in the following answer: What exactly is a headless service, what does it do/accomplish, and what are some legitimate use cases for it?

„Instead of returning a single DNS A record, the DNS server will return multiple A records for the service, each pointing to the IP of an individual pod backing the service at that moment.”

Thus the pods in back-end layer can communicate to each other.

I can’t use dig command. It is not installed in minikube. Eventually how do I install it? There is no apt available.

I hope this explains more accurately what I want to achieve.

Answer 1

You mentioned that you want to receive IP addresses associated with pods for selected service name for testing how does headless service work.

For only testing purposes you can use port-forwarding. You can forward traffic from your local machine to dns pod in your cluster. To do this, you need to run:

kubectl port-forward svc/kube-dns -n kube-system 5353:53

and it will expose kubs-dns service on your host. Then all you need is to use dig command (or alternative) to query the dns server.

dig @127.0.0.1 -p 5353 +tcp +short <service>.<namespace>.svc.cluster.local

You can also test your dns from inside of cluster e.g. by running a pod with interactive shell:

kubectl run --image tutum/dnsutils dns -it --rm -- bash
root@dns:/# dig +search <service>

Let me know it it helped.