Get docker image name

[llrs]

There is a function on the package (get_image_name) assuming there is a variable reporting the name of the image. Make sure that it works on all docker images or with the ones provided by rocker or other common R efforts

[rabiibouhestine]

I see that the function already has a fallback to params$image if set or if not then the default value "rhub/ref-image", this technically makes it "work" on all docker images, did you perhaps mean there could be other names for the environment variable DOCKER_IMAGE that we need to capture?

[llrs-roche]

Yes, basically I want to make sure we report the right name of the image. But I might have analyzed the function incorrectly (I haven't run it on a container to see how it works on that case).