Duplicating docker container for debugging

1. Create a base image and run it

   docker run -it <base_image> /bin/bash
   

2. Make necessary changes

   yum install ping
   

3. Commit it with a new name

   docker commit <hash tag of running container> new_image
   

Now if you open new_image by running

docker run -it new_image /bin/bash

You can see ping is installed in it.

Open base_image and there is no ping installed in it.

Hope it answered your question.