Add an install option to kubectl command

[afbjorklund]

• Add --install option to minikube kubectl command
• Add --path option to minikube kubectl command

Usage:
  minikube kubectl [flags]

Flags:
  -h, --help            help for kubectl
      --install         Install kubectl and exit
      --path            Display kubectl path instead of running it
      --prefix string   Installation prefix (default "/usr/local")

For #4697

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[josedonizetti]

won't this default prefix be a problem for windows?

[afbjorklund]

Probably, but haven't used anything but MSYS myself.

[josedonizetti]

Yeah, I'm not a windows user as well. It worries me that downloading kubeclt currently works on all platforms, and now considering this default prefix it will break in windows. Does it make sense to only use the prefix when in non-windows systems? It basically does the previous behavior for windows, and we add an issue for someone else to implement the windows support.

[afbjorklund]

I can add another prefix (already have a suffix...), just not sure what it would be

[josedonizetti]

without reading the help command I would consider that path would be the place to install, pretty much like prefix.

what do you think about --which cos it does the same thing as which kubectl, right? probably wouldn't make the same sense for a windows user.

[afbjorklund]

Yeah, that is one idea. I copied --url (from dashboard), and then it became --path.

[afbjorklund]

Think --which can be misleading, since it is normally associated with PATH (which it is not in). Will go for something like --print, and hope that there is no confusion.

[afbjorklund]

AFAIK, Windows doesn't have the concept of a default PATH ?

You choose C:\any\random\path and then set up variables and crap.

So I suppose one would have to use --prefix ?

Or another approach, such as running in MinGW.

[tstromberg]

I prefer that minikube not be in the business of installing system binaries when possible. I don't mind downloading kubectl to our own folder, but I feel that this duty is better left to a package manager.

[afbjorklund]

Okay