Added -headless argument to start the server without serving the frontend

[Paloys]

Added -headless argument to start the server without serving the frontend, and completed the galene-protocol.md to mention it where I thought it would be useful. Feel free to ask me to document the change somewhere else if necessary !

[jech]

We need to find a better name than "-headless". I'm thinking of "-no-static". Any better suggestions?

I'm not entirely clear why this is needed, though. If the user simply does a "rm -r static/", the server will serve 404 for all static requests; isn't that good enough?

Finally, could you please squash your commits?

[Paloys]

-no-static sounds good to me.

I think it is needed to let the user have flexibility when running in a container : modifying the content of the docker image is more annoying than just passing an argument to the starting command.

And I squashed the commits

[jech]

I think it is needed to let the user have flexibility when running in a container : modifying the content of the docker image is more annoying than just passing an argument to the starting command.

Since it's a fairly small amount of code, I'm not opposed to merging it, but I'm really not convinced. If the user is using a Galene server with their own frontend, then they'll probably be building their own Docker container, adapted to their very specific needs (or, hopefully, doing the right thing and not using Docker in the first place). Can you please describe a deployment in which the user want to disable the static pages, but doesn't want to build their own Docker image?

Issues:

• -no-static should not be disabling public-groups.json;
• please fix the documentation (or leave it undocumented, that's fine too). The stray sentence that you added to galene-protocol.md is not helpful.

[jech]

@valentt, any opinions?