WhaleTail is a Go program which is designed to reverse engineer a Docker Image into the Dockerfile that created it. It currently performs the following actions

• Generates a Dockerfile from an Image
• Searches added filenames for potential secret files
• Extracts files that were added by the Docker ADD/COPY Instructions
• It also displays misc. information such as ports open, the user it runs as and environment variables.

You can read more about this on my blog Here

Git clone the project into your $GOPATH/src directory and perform the following command

cd $GOPATH/src
git clone https://github.com/P3GLEG/WhaleTail
go build .

./WhaleTail
Usage of ./WhaleTail:
  -f string
    	File containing images to analyze seperated by line
  -filter
    	Filters filenames that create noise such as node_modules. Check ignore.go file for more details (default true)
  -v	Print all details about the image
  -x	Save layers to current directory