Docker remote debugging support

[factyy]

Hi everyone!

I want to help (if I have the time though) with dockerized debugging (both an app and a debug server residing inside a container). Any tips or hints?

Edit: this is a part of my lsp-mode wishlist suggestions: emacs-lsp/lsp-mode#515 (comment)

[yyoncho]

I will do it like this:

1. Change dap-mode to be able to start remote debug adapter and communicate with it.
2. Set dap-print-io to t and inspect that we are sending the correct local path to the debug adapter. We can put in the debug session function which translates the paths or we can eventually use that same function but from the lsp--client that is used by the current fine. I am not sure which approach will be better.

[adasium]

There will also be a need to store currently used template somewhere, right? Since the user might define various mappings for different templates.

[yyoncho]

@milochadam yes.

[factyy]

@yyoncho I started to work on this feature at last. Decided to stick with option 2: using lsp--client features (lsp--path-to-uri with DAP mode changed to "uri" from "path" in the initialization request)

[factyy]

And quickly got a problem that not all debug providers support URIs...
Ok, we need new translation functions (the ones provided by lsp-mode work only with URIs)

[yyoncho]

@factyy we can transform to uri and back I guess.

[factyy]

Filed a PR #559, closing this issue