Step by step guide on how to install CKAN 2.9.0 with Docker

Hi, everyone!

A couple of months ago I wrote a guide on how to install and configure CKAN 2.9.0 using Docker. Especially considering that the official documentation was inaccurate about how to do it, I figured it may be useful to other people experimenting with CKAN, but for some reason did not remember to share it on this forum until now.