Redirect to HTTPS when SSL is enabled

[tylersmalley]

Previously we were using httpolyglot to serve multiple protocols over the same port, which resulted in choosing to remove it.

This feature is for those who are exposing the server directly, otherwise, it would make more sense to handle the SSL termination and redirection at the load-balancer.

The currently proposed solution would be to automatically bind to port 80 if server.ssl.enabled is true and server.port is set to 443. Allowing us to redirect traffic from http://${server.host} to https://${server.host}.

A concern with this approach is the assumption that there is nothing else binding to port 80. It's possible to gracefully handle this scenario. Alternatively, we could provide configuration to override this port or disable the redirection/binding entirely.

[tylersmalley]

@epixa - I am having a hard time thinking of a reason why you would want the redirect to happen on a port other than 80/443 so I excluded my suggestion of providing server.httpPort and server.httpsPort

[jbudz]

In on redirects but I'm iffy on the approach. As a server admin I would want to know exactly what my configuration is doing, and autobinding when 443 would involve some magic that would be unexpected for me.

Taking the concern a step further, although unlikely, what if on restart kibana beats that service to port 80? No problem if I explicitly said redirect port 80, but if it's automatically happening it could cause some confusion.

[epixa]

You've convinced me with that startup scenario. How about a redirectFromPort80 configuration flag for ssl?

[jbudz]

Closed by #10930