docker: how to show the diffs between 2 images

Question

I have a Dockerfile with a sequence of RUN instructions that execute \"apt-get install\"s; for example, a couple of lines:

RUN apt-get install -y tree
RUN apt-ge         


        

Answer 1

This one worked for me:

docker run -it e5cba87ecd29 bash -c 'find /path/to/files -type f | sort  | xargs -I{} sha512sum {}' > /tmp/dockerfiles.e5cba87ecd29.txt
docker run -it b1d19fe1a941 bash -c 'find /path/to/files -type f | sort  | xargs -I{} sha512sum {}' > /tmp/dockerfiles.b1d19fe1a941.txt
meld /tmp/dockerfiles*

Where e5cba87ecd29 and b1d19fe1a941 are images I am interested in and /path/to/files is a directory which could be "/". It lists all files, sorts it and add hash to it just in case. And meld highlights all the differences.