Updating script to work in 2019

[JackDanger]

This change pins the Docker image to a modern Alpine and introduces Gemfile.lock for pinning gem versions.

Using a Docker image built on this PR we can recreate the Dockerfile of the image:

$ dockerfile-from-image dockerfile-from-image:latest
FROM alpine:latest
RUN apk --update add gcc libc-dev make ruby ruby-dev ruby-irb ruby-json && gem install --no-rdoc --no-ri bundler -v 1.16.1 && rm /var/cache/apk/*
WORKDIR /usr/src/app
ADD file:8846919c69ba1db0d696b60c308789910d605613efbaabc9a39e922cefda1d9d in /usr/src/app/
ADD file:d4a7c1736d3fdf8b52906ed2f4e9b10cd5632a382fd493af2c6531fd11173a1f in /usr/src/app/
RUN bundle
ADD file:3ee34f17db9fd9bd8d12051a7959f986ae8705ba392c2d4f2bd28e097a896dde in /usr/src/app/dockerfile-from-image.rb

[sokoow]

Woohoo! :D

[mdiasfernandes]

Thanks @JackDanger, it's fully working 👌

[ozbillwang]

Not really

git clone git@github.com:JackDanger/dockerfile-from-image.git JackDanger/dockerfile-from-image
cd JackDanger/dockerfile-from-image
docker build -t dfimage . 
alias dfimage="docker run -v /var/run/docker.sock:/var/run/docker.sock --rm dfimage"
docker pull devopsqa/fortify

dfimage devopsqa/fortify
/usr/src/app/dockerfile-from-image.rb:33:in `block in <main>': undefined method `first' for nil:NilClass (NoMethodError)
	from /usr/src/app/dockerfile-from-image.rb:32:in `each'
	from /usr/src/app/dockerfile-from-image.rb:32:in `each_with_object'
	from /usr/src/app/dockerfile-from-image.rb:32:in `<main>'

I am looking for a image to run with fortify, and find it in hub.docker.com. I 'd like to reverse its Dockerfile. this image devopsqa/fortify is huge,

docker images devopsqa/fortify
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
devopsqa/fortify    latest              9db34bb78a6e        2 years ago         3.04GB