recently I had a need to execute CentOS image with bash. Following command proved helpful for me:
docker run -i -t --rm centos /bin/bash
Then at executed image you can do whatever you want. For example I had a need to validate DNS server activity.
For this purpose I had to find what provides dig.
Following command told me what:
yum whatprovides dig
And next command installed:
yum install bind-utils