Getting to grips with Docker

This month’s tutorial will hopefully show you that Docker is nothing to be afraid of, and once it’s installed you can start doing some cool stuff using just a handful of commands. You can use it for hosting your own servers, but it’s also handy for quickly summoning up an isolated shell for experimentation. For the uninitiated among you, let’s get into what Docker is and why it’s such a useful tool for all Linux users.

Docker manages so-called containers. These containers are sandboxed processes that seem, to the applications and services within them, to be complete Linux systems. So far, this might sound like we’re describing virtual machines (VMs), but there are important differences between containerisation and virtualisation. In the case of virtualisation, the virtualiser emulates the hardware of an entire computer, and this is resource intensive.

With containerisation, a process contains the applications and services, and is separated from the rest of your system. By employing the features of the CPU and the Linux kernel, the host system is protected from whatever’s going on inside the container. You’re typically running the container as a normal user rather than as the system super-user, despite the fact you’re doing things like editing system files and installing Linux packages within the container.

This approach takes a lot of the stress out of experimenting with servers and other projects, because containers mean you don’t have to make any changes to your host system. containers are fast to deploy and use as well. If you