Use preview in container

[etiennebacher]

Also, and while we abuse this as a "chat": One thing that was supposed to work but didn't (and I know too little about servr and friends): preview does not work out of the Docker container. I know how to expose a port, and run other containers delivering webpages, dashboards, ... etc. Nada for altdoc. As the container locally-mounts the filesystem I got the preview from outside the container (as preview only requires R infrastructure that I have anyway).

Any idea how we'd go about fixing / debugging this? It is a missing piece in making altdoc self-contained in a container.

Originally posted by @eddelbuettel in #339 (comment)

[etiennebacher]

Sorry, I have no clue about that and I don't use containers so it would be hard for me to easily try and test stuff. Maybe @vincentarelbundock or someone else will be able to help you more.

[eddelbuettel]

Thanks for carrying this over. I didn't want to "impose" as this might have been considered a fringe issue so I didn't jump to opening an issue rightaway. I apprecoate you swatting the once I filed so quickly though :) Happy to help here, but also do not know where to start as I don;t usually rely on servr and alike.