Shared Volumes

A common configuration with Rocker containers is to share volumes between the container and the host filesystem. This allows the container to access and modify local files in directories you specify. In this way, the container can be treated as ephemeral while files you create will persist after the container is destroyed. Because the container only has access to files within the directories you specify, this can also prevent a user from accidentally modifying unrelated files on the file system when using software inside the container.

To share a volume with the host we use the -v or --volume flag. Simply indicate the location on the host machine on the left side of :, and indicate the location on the container to the right. For instance:

docker run -d -p 8787:8787 -v /Users/bob/Documents:/home/rstudio/Documents rocker/rstudio

would link the User bob’s Documents directory to the default rstudio user’s directory on the container. The above example shows a typical path on a Mac host, which can share any subdirectory under Users. A Linux host can link an arbitrary path. The same method should work on Windows paths as well, e.g.

docker run -d -p 8787:8787 -v /c/Users/foobar:/home/rstudio/foobar rocker/rstudio

Would share the host’s file C:/Users/foobar

Kitematic

Users of the Docker’s GUI interface, Kitematic, who use the rstudio-derived images will automatically have their local kitematic directory linked to the /home/rstudio/kitematic directory on the Docker container. This provides a seamless interface to Docker and the Rocker images without any need for shell commands.