I am looking into
Interesting question, but I'm not sure I understand the advantage of having the shiny-server and the rstudio-server instances served from the same container.
Is the purpose so that the two containers share the same R libraries (e.g. so a package doesn't need to be installed separately on each) or merely to have one docker container instead of two? Just having to run two docker commands instead of one doesn't seem that onerous, but maybe I'm underestimating.
Sharing the underlying libraries seems like a valid objective though, and I don't think there's an ideal solution available yet.
I feel the most docker-esque solution would be to do this via container orchestration/compose tool as you mention. This is the usual way to combine separate services (e.g. web server and database) without building one on top of the other.
Unfortunately, the tooling for orchestration based on mapping volumes is not nearly as well developed as it is for mapping ports.
Imagine running the rstudio as a volume container:
docker run --name rstudio -v /usr/local/lib/R/site.library rocker/rstudio true
(If you wanted RStudio access at the same time, one could instead run this as:)
docker run --name rstudio -dP -v /usr/local/lib/R/site.library rocker/rstudio
You can then use the the site.library from the rstudio container in place of that on the shiny container with a command like:
docker run --volumes-from rstudio -dP rocker/shiny
Unfortunately, this clobbers the
site.library of the
shiny container. To work around this, you'd want to mount the library of the rstudio container in a different place, but there's no easy syntax for this like we already have with port links. It can be done though, see:
There's an open thread on this issue in the rocker repo too.