Docker is sheer magic. You don't have to understand it to run it. However, if you insist on knowing how it is done...
Here are ten steps to install RAP4 manually, without Docker, on a freshly created server:
1. Setting up a server
You need a server that is connected to the internet, because RAP takes updates from a GitHub repository. A 2-core/8GB server is sufficient. A memory size under 3GB has shown to be insufficient. Ports for HTTP, HTTPS, SSL, and SFTP must be open.
2. Getting MariaDB (MySQL) and phpMyAdmin to work
You need a database and a web-server. This explains why a LAMP-server is an obvious choice if you use a preconfigured server.
3. Uploading and running RAP4
A quick way to install is to copy the source code of RAP4 on your server and compile it with Ampersand. That gives you the RAP4 webapplication. You will find the complete Ampersand source code of RAP4 on https://github.com/AmpersandTarski/RAP. The main file is ./RAP4/RAP4dev.adl for the development version and ./RAP4/RAP4prod.adl for the production version.
4. Filling the Git repository with Ampersand files and Ampersand models
If you don't have an Ampersand compiler, you can build one using the Haskell sources of that compiler. You will find the source code on the development branch of the Ampersand repository (https://github.com/AmpersandTarski/Ampersand/tree/development). You can verify success by asking the Ampersand for its version:
> ampersand --version
Ampersand-v3.17.4 [master:fd90ea3f1], build time: 15-Nov-19 18:02:19 CET
If you don't have an Ampersand compiler, but docker runs on your machine, you can simply use the most recent ampersand compiler by
> docker run -it ampersandtarski/ampersand
Use Git to create a local clone of these repositories. Git is preferred over copying the files, because you can repeatedly use it to ensure you get the right version.
5. Avoiding to install Haskell
To build an Ampersand compiler, you need Haskell. However, you can also use the latest executable Ampersand-compiler, which is published periodically on http://ampersandtarski.github.io/. This way, you don't need to build Ampersand and you can avoid installing Haskell.
6. Creating an Ampersand compiler
If you want, create your own Ampersand compiler. This way, you can pick a version by which to generate RAP4.
7. Installing LaTeX and GraphViz
LaTeX and GraphViz are called by RAP4 to generate documentation. Therefore, both must be installed on the server.
8. Generating the RAP4 application
You need to generate RAP4 to facilitate regular updates to the system.
9. Local Settings
Some local settings may apply, which are brought together in one file. Use this to administer things like database account(s) and PHP time limit, logging, etcetera.
10. Last minute changes before going to production
Things that are necessary for testing and development, such as logging, can be changed in the production version. These things are usually adapted shortly before going to production.