The kubeconfig.yaml generated by K3S uses local host as the host name by
default. It won't work when running with docker machine.
This patch detects if the docker environment is set up with docker
machine. If it is, then replace the host name to the IP address of
the docker machine.
Add the basic frame work for supporting spawning a bash shell by cli
command.
With this change, we can spawn a bash shell in the context of a cluster
$ k3d create -n my-cluster
$ k3d bash -n my-cluster
[my-cluster] $>
// execute commands with KUBECONFIG already set up
[my-cluster] $> kubectl get pods