This guide has now moved to here https://github.com/OnniSaarni/SPT-Fika-Docker-Guide
This gist can still be used for discussion if you'd like.
Feel free to make an issue or a pull request if you'd like to contribute by expanding some sections or just otherwise contributing something to the guide.
Scripts and automated tools are welcome too if you wish to have them in the repo.
Would like to say a big thank-you for this guide. I've been struggling to install SPT Server to a raspberry pi running Ubuntu and this guide was super simple and I was up and running playing Co-Op with friends in uder an hour, great work, thank you :)