How to see commit message from docker images

Question

I am new to docker and begin playing with it. I have created a few images from committing a few changes. Started with

sudo docker run -i -t ubuntu /bin/bash

doing a few installs, exited and did

sudo docker commit -m="my first message" innocent_dockernovice sandbox/yves:s1

and repeting the process

sudo docker run -i -t sandbox/yves:sN /bin/bash

doing stuff in shells, exiting and

sudo docker commit -m="what I did in step N" happy_dockeruser sandbox/yves:sN+1

Now I want to go back to a previous step image and would like to list all the messages doing a sudo docker image -m kind of command similar to a git log one. What is the best way to do it?

Answer 1

You can view commit messages by using docker inspect on the commit hash displayed afterwards. To view more of them you must do it recursively.

$ docker commit -m "added test file" sick_morse
61efdbd141dc5fb1c289ed5151f3ce7b5985a5829bd92ba322ad6061cb1eee21
$ docker inspect 61efdbd141dc5fb1c289ed5151f3ce7b5985a5829bd92ba322ad6061cb1eee21 | grep added
    "Comment": "added test file",

Found info here

This would let you view the messages for the top 3 most recent comments.

$ docker images -a --no-trunc | head -n4 | grep -v "IMAGE ID" | awk '{ print $3 }' | xargs docker inspect | grep Comment

Answer 2

To make things simple, i did a simple bash script in github gist: docker-log

#!/usr/bin/env bash

DOCKER=`which docker`

if [ "$#" -ne 1 ]; then
  echo "Usage: $0 IMAGE"
  exit 0
fi

for commit in $($DOCKER history $1 | sed 1d | awk '{ print $1 }')
do
  content="$commit
$($DOCKER inspect $commit | tr -d '\"' | grep 'Created\|Author\|Comment')"
  echo "$content"
done

Snapshot for usage: