Useful Docker oneliners

Display image virtual size in human-readable format:

sudo docker inspect <image> | grep -i VirtualSize | awk '{$2/=1000000; printf "%.2f MB\n",$2}'

Checking what command has produced specific Docker image layer:

docker inspect --format '{{ ((index .ContainerConfig.Cmd ) 0) }}' <layer_id>

Useful Docker-related links:

https://imagelayers.io/
https://github.com/larsks/dockerize