Getting started with Docker

Lately there has been a big fuss about Docker; that instead of lumping everything on one server you split your app in to different containers (tiny virtual machines) to make both scaling and developing on easier.

Vagrant is good, but it takes time to write proper provisioning scripts (especially for larger projects with multiple services), maintaining them, and ensuring pesky developers don't update the VM directly without keeping the provisioning script up-to-date.

Docker aims to eliminate that, and after using Kitematic for a Wordpress (shudder) project -- I must say I'm impressed, so much so that I'm going to start to get to grips with it properly instead of using a lovely GUI.

Whilst following the installation instructions I came across a difficulty in that I couldn't run the simple docker run hello-world command. I kept getting these errors:

Post http:///var/run/docker.sock/v1.20/containers/create: dial unix /var/run/docker.sock: no such file or directory.
* Are you trying to connect to a TLS-enabled daemon without TLS?
* Is your docker daemon up and running?

As it turns out, I was being incredibly stupid. I hadn't realised my terminal had escaped back to Bash and that I was no longer in the Docker Quick Start Terminal shell...