Having used Docker. for over 5 months I can safely say that Docker is exceptional in Operations.

  1. Divergence. Here are two ways your servers can Diverge from your expectations.

    • User

      Someone logged in and modified a file that is not controlled by Chef. This file could be a critical file or innocent, the problem could be that it was not done in a way that could be repeated easily (or distributed to all servers).

    • Automation

      Having Unattended Upgrades. configured and having it fail on some servers

The problem I have described here with Divergence is that Chef cannot revert a change to a file it is not in control of. Things that happen outside of Chef's control create results that cannot are not predictable.

  1. Speed of Delivery

    General reduction of complexity to deliver something. Breaking a large brittle product into smaller components

  2. Shipping a product in a working state.

    For example you can take a working image from 4 months ago and pull it down on a new server and t will just work

Docker by itself is powerful but without any automation or orchestration it can be the opposite.