Do I need OpenStack if I use Docker?

Docker has broken a record in the speed in which it moved from being a disruptive technology to a commodity. The speed of adoption and popularity of Docker brings with it lots of confusion. In this post I wanted to focus on a trend of commentary that has been gaining popularity that I’ve started to hear more often recently from users who just started using Docker: whether it makes sense to use OpenStack if they’ve already chosen to use Docker. Before I give my take on this, I want to start with a short background for the rationale behind this question.