Disabling the /admin/shutdown admin endpoint

[Alex Leong]

Hi Linkerd friends!

I wanted to solicit some community input on this Linkerd issue: https://github.com/linkerd/linkerd/issues/2033

I know many people have had concerns about the /admin/shutdown admin endpoint and have wanted a way to disable or secure this endpoint.  More broadly, there are a number of admin endpoints which are potentially dangerous and might need to be secured.

If you have any opinions or requirements about the way this is implemented, please comment on the issue.

Thanks!

Alex