A web screenshot container based on phantomjs's rasterize.js.
Based on a phantomjs container.
$ git clone https://github.com/piether/docker-screenshot.git
$ cd docker-screenshot
$ docker build -rm -t screenshot .
Because phantomjs runs inside the container, you need to bind mount a volume to retrieve the screenshot.
The container is configured to write screenshots to /srv, so bind-mounting $PWD (or whatever directory you want to screenshot created in) to it seems like a good idea.
$ docker run -v $PWD:/srv screenshot http://www.alfred-shop.de/artikel/00-PVM04059DPNS sc3.png 1920px 2000