For anyone that might find this helpful if you are thinking of hosting games with either the old Source game-engine (https://en.wikipedia.org/wiki/Source_(game_engine)) or the ancient GoldSrc game-engine (https://en.wikipedia.org/wiki/GoldSrc) on a headless Linux server, I have published my scripts and built a Steam Community "Guide" for their setup and usage ...

Weasel's Dedicated-Server Management Scripts (for Linux)
https://steamcommunity.com/sharedfiles/filedetails/?id=3192671225

The sample scripts provided allow for easily completing many tasks associated with hosting dedicated game-servers. This includes things such as:

* Installing the game-servers in a consistent manner.
* Running the game-servers interactively at the console for testing / troubleshooting.
* Starting the game-servers as disconnected / back-ground processes - so that they can run unattended.
* Stopping the disconnected / back-ground processes of the game-servers.
* Manually updating the game-servers if needed.
* Checking for updates available for the game-servers, and conditionally updating the game-servers, restarting them only if an update is needed.
* Making backups of the game-servers.
* Generating lists of "stock" content to exclude from backups.