Simple shell script to diff Docker image layers, see which layers was changed between two images.

docker-layers-diff.sh

#!/bin/sh

# Usage:
# docker-layers-diff image-1 image-2

set -e

if [ -z "$1" ] || [ -z "$2" ]; then
  echo "Missing 1 / 2 args"
  exit 1
fi

echo "Pulling images"
docker pull "$1" -q
docker pull "$2" -q

docker inspect $1 | jq '.[].RootFS.Layers' > /tmp/${USER}-$$-docker-layers-diff-1.json
docker inspect $2 | jq '.[].RootFS.Layers' > /tmp/${USER}-$$-docker-layers-diff-2.json

diff -y --color /tmp/${USER}-$$-docker-layers-diff-1.json /tmp/${USER}-$$-docker-layers-diff-2.json

rm -f /tmp/${USER}-$$-docker-layers-diff-1.json /tmp/${USER}-$$-docker-layers-diff-2.json