Finding the layers and layer sizes for each Docker image

Question

For research purposes I\'m trying to crawl the public Docker registry ( https://registry.hub.docker.com/ ) and find out 1) how many layers an average image has and 2) the si

Answer 1

Not exactly the original question but to find the sum total of all the images without double-counting shared layers, the following is useful (ubuntu 18):

sudo du -h -d1  /var/lib/docker/overlay2 | sort -h