add support to visualize the Dockerfile from a docker image

[larrycai]

will be interesting to see dockviz can support generating Dockerfile from docker image as well.

see related blog/solution

• http://abdelrahmanhosny.com/2015/07/11/how-to-merge-two-docker-images/#comment-532
• one ruby implementation for this https://github.com/CenturyLinkLabs/dockerfile-from-image

[justone]

Interesting idea. I'll look into it at some point.

[gesellix]

Hey, I made a combined image for personal use, but it might help you to build a more generic variant. I also stumbled over some dynamic library issues when running a dockviz release in an Alpine image (using musl libc instead of glibc), which is why I build the binary during the Docker build.

See https://github.com/gesellix/docker-tree-viz for the source.

[justone]

@gesellix Interesting idea. I created a new issue to talk about the docker image over here: #22