Here is the software referenced in the previous documentation.
Turnkey GNU/Linux is a free Debian based library of system images that pre-integrates and polishes the best free software components into secure, easy to use solutions.
This location contains all of the Turnkey Linux disk image files. Download the package and the format you need. You can then assign it to a virtual server or add it into a container.
How to pick the right version
In this example, there are five files which support the same application (ansible). There are four versions (14.1, 14.2, 15.0, and 15.1). There are two platforms one supports 32bit servers and the other 64 bit servers (i386 and amd64).
Traditionally, you want to pick the latest and greatest, which would be "turnkey-ansible-15.1-stretch-amd64", if you want to use a 32bit server, then your only choice is "turnkey-ansible-14.1-jessie-i386".
Download the appropriate file and you should be good to go.
turnkey-ansible-14.1-jessie-amd64.iso 2016-04-08 09:28 265M turnkey-ansible-14.1-jessie-i386.iso 2016-04-10 12:00 269M turnkey-ansible-14.2-jessie-amd64.iso 2017-08-02 04:11 317M turnkey-ansible-15.0-stretch-amd64.iso 2018-09-19 06:20 387M turnkey-ansible-15.1-stretch-amd64.iso 2019-05-09 03:48 426M
Special problem with Docker, 32bit doesn't exist natively. You will need to build the hosting server yourself, from source code.