On the surface Docker looks like another virtual machine (VM). Just pick Ubuntu image with hello-world app inside, type docker run ubuntu hello-world in your terminal of choice, and hello-world will start, thinking it owns a whole machine running Ubuntu.
But Docker is not a VM, manager of VMs, or hypervisor of any kind. Docker is a platform for creating, launching and managing containers. Those looks like VMs, quack like VMs, but are much closer to a fence with a barbwire on top of it. No app can enter, no app can leave. What is bad for humans works great for applications in production environment.
Because Docker doesn’t have to deal with guest operating system and hardware abstraction, it can work with the speed that VMs can only dream of, while doing quite similar job. Continue reading “Quick intro to Docker”