Count docker images layers

count-docker-layers.sh

#!/bin/bash
image=$1

usage () {
    echo -n "Usage: $0 <full-image-URL>

Count number of layers of given Docker image

Options:
-h, --help    Display this help and exit
"
    exit 1
}

if [ "$#" -lt 1 ]; then
    usage
fi
if [[  $1 == "--help" ||  $1 == "-h" ]]; then
    usage
fi

docker inspect $image | jq ".[0].RootFS.Layers" | sed '1d;$d' | wc -l