Romana DNS

Romana DNS

Romana DNS adds DNS support for Romana IPs. It is drop in replacement for kube-dns.

Install Steps

On Master node of kubernetes cluster

• Make a note on number of replicas for kube-dns using following command:

echo `kubectl get deploy -n kube-system kube-dns -o jsonpath="{.spec.replicas}"`

• Now set replicas for kube-dns to zero using following command:

kubectl scale deploy -n kube-system kube-dns --replicas=0

• Wait till kube-dns replicas are zero (around a minute or so)

On All nodes i.e master and compute nodes of the kubernetes cluster

• Remove earlier docker images and replace it romana one using commands below:

docker rmi gcr.io/google_containers/k8s-dns-kube-dns-amd64:1.14.5
docker pull pani/romanadns
docker tag pani/romanadns:latest gcr.io/google_containers/k8s-dns-kube-dns-amd64:1.14.5

• Now return back to master node for further commands

On Master node of kubernetes cluster

• Now assuming you had 2 replicas before, from first step above, we restore the replica count for kube-dns as follows:

kubectl scale deploy -n kube-system kube-dns --replicas=2

• Wait for a minute or so for the pod to come up and we have romanaDNS up and running.

Testing

• Run dig to see if dns is working properly using command:

dig @10.96.0.10 +short romana.kube-system.svc.cluster.local

• Download this sample nginx yaml file and then use following command to create an nginx service with RomanaIP in it:

kubectl create -f nginx.yml

• This should create and load nginx service with RomanaIP, which should reflect in the dig result below:

dig @10.96.0.10 +short nginx.default.svc.cluster.local

Sample Results

$ dig @10.96.0.10 +short romana.kube-system.svc.cluster.local
10.96.0.99
192.168.99.10
$ dig @10.96.0.10 +short nginx.default.svc.cluster.local
10.116.0.0
10.99.181.64
192.168.99.101