Foreword

I might be biased, but Docker is a pretty big deal.

It wasn’t long ago that applications were large and monolithic, sitting alone inside lumps of steel and silicon. They would stew away for a few years, resisting change, not wanting to move. This was a problem for organizations that wanted to move fast, so it’s no surprise that virtual machines caught on. Applications were no longer tied to these pieces of hardware, allowing everything to move more quickly and be more flexible.

Unfortunately, virtual machines are very complicated. They simulate an entire computer inside of another computer, and this virtual computer is still very complex and needs managing. And because virtual machines are smaller and easier to create, there are far more of them around that need managing.

How do we manage all of that complexity? With configuration management, of course—another extremely complex system for managing complexity.