I created a kubernetes cluster 3 using vagrant machines and installed helm. But when checking the version of helm it gives the version of client and says "cannot connect to tiller. I can't install any chart using helm due to an error related to forwarding ports.

vagrant@master:~$ helm init

$HELM_HOME has been configured at /home/vagrant/.helm.
Warning: Tiller is already installed in the cluster.
(Use --client-only to suppress this message, or --upgrade to upgrade Tiller to the current version.)
Happy Helming!

vagrant@master:~$ helm version

Client: &version.Version{SemVer:"v2.6.2", GitCommit:"be3ae4ea91b2960be98c07e8f73754e67e87963c", GitTreeState:"clean"}
Error: cannot connect to Tiller

vagrant@master:~$ helm install nginx

Error: forwarding ports: error upgrading connection: unable to upgrade connection: pod does not exist

I found a solution here :

https://kubernetes.io/docs/getting-started-guides/ubuntu/troubleshooting/

This is caused by the API load balancer not forwarding ports in the context of the helm client-server relationship.

But the procedure to solve the error is not clear for me.

For example, the first step says to expose the Kubernetes Master service :

   juju expose kubernetes-master

But i use kubectl instead of juju. So how can i find the name of k8s master service? and how should do this step using kubectl?

In short, I want to do the steps using kubectl, instead of juju.And i don't understand the difference.

Can anyone help me?