Minikube: Kubectl install hint on `minikube start`

[r2d4]

Is this a BUG REPORT or FEATURE REQUEST? (choose one): Feature Request

Minikube requires kubectl for any meaningful behavior. The download links for standalone kubectl aren't that easy to find and aren't well documented. If the user doesn't have kubectl, we should output a hint with the install command during startup

Starting cluster...
To interact with the kubernetes cluster, please download the kubectl client 
using `gcloud component install kubectl` or 
curl -Lo kubectl http://storage.googleapis.com/kubernetes-release/release/$DEFAULT_MINIKUBE_K8S_VERSION/bin/linux/amd64/kubectl && chmod +x kubectl && sudo mv kubectl /usr/local/bin/
....

[r2d4]

Thumbs up this comment if you think that minikube should just bundle kubectl and offer the option to install it right from the binary

[jimmidyson]

I think minikube should offer to download & install latest version of kubectl if it can't find it in PATH. It could also offer to update the version if it's an old version. I don't like the idea of bundling it personally, prefer to download it if required.

[aaron-prindle]

Currently plan on doing the kubectl check is to check the OS minikube is running on and then running the appropriate shell cmd for the os to check that minikube is on the path. Something like:
Linux/OSX:
http://stackoverflow.com/questions/592620/check-if-a-program-exists-from-a-bash-script
Windows:
http://stackoverflow.com/questions/4781772/how-to-test-if-an-executable-exists-in-the-path-from-a-windows-batch-file

Please let me know if you have any feedback/alternatives. Thanks.

[r2d4]

We use exec.LookPath in the integration tests

https://golang.org/src/os/exec/lp_unix.go?s=931:973#L24

[aaron-prindle]

Yea, just saw this lol. Thanks.