Allow proxying sub-paths to other server implementation for better development cycle

[hejfelix]

When developing react apps, I've been using webpack proxy to forward /api/* to e.g. localhost:9000/api/* for speedy development of single page web apps.
Correct me if I'm wrong, but I don't see any way to proxy servers with workbench.

Effectively, this gives my web-app the illusion that it is being hosted on the actual server allowing me to keep relative paths everywhere. (autowire is not an option for me currently).

Would it be much work to add a configuration to forward some sub-path to a user chosen URL?

[ochrons]

Do you mean a real proxy or just a redirect? If you can provide an implementation in a PR, I'm happy to include it :)