This is a Docker image based on https://github.com/envygeeks/jekyll-docker, but ignoring the slow chown dance. It is used by Jenkins.
It can be used locally like this:
docker run -e JEKYLL_ENV=development --rm --volume="$PWD:/srv/jekyll" docker.gbif.org/fast-jekyll:4.1.0 \
bash -c "jekyll build; /chown -R "$(id -u):$(id -g)" _site"