Autostop feature

[Oekn5w]

implements #1211 according to Discord description.

[javabrett]

Thanks for the PR @Oekn5w .

As my launch-time version of this amounts to a oneline sed of the existing autopause pause.sh script:

sed -i -e "s/pkill -STOP java/rcon-cli stop/" /autopause/pause.sh;/start

... and the functionality (in terms of detect-idle, zero players) is otherwise identical to autopause, I wondered if an approach that shoehorns a custom action into the existing autopause could work, provided it isn't confusing ... as an alternative to duplicating /autopause as /autostop - or are there other differences (I haven't compared them yet)?

So I was debating one of the following:

• Adding ENABLE_AUTOSTOP, having it set and trigger ENABLE_AUTOPAUSE transparently, but with rcon-cli stop as the action in pause.sh when the new variable is set. Downside is the slightly confusing running of the autopause scripts (including potentially pause.sh but with autostop behaviour, but this seems minor.
• Adding variable AUTOPAUSE_STOP default false. Makes it clear that autostop is a variant of the autopause behaviour, requires ENABLE_AUTOPAUSE=true. Variant would be AUTOPAUSE_ACTION=pause with option for stop.
• Variants where just pause.sh is copied to stop.sh.

My current leaning is towards the first of these. WDYT - or are there other advantages in forking autopause to autostop entirely?

[Oekn5w]

@javabrett

As there are major differences with how the feature works and requires outside container configuration, I thought this approach is more viable to avoid confusion compared to cobbling this together with a startup sed command.

Autopause does require a lot of validation and configuration for the knockd stuff, which is not needed for Autostop. Additionally we can provide a nice log message with the correct name.

[itzg]

I agree with the general observation @javabrett that it looks like more code duplication than expected; however, I do also agree @Oekn5w with the improved usability with the current approach.

[itzg]

I still need to research how can have GitHub actions do a one off test-image build for PRs, as needed. However, maybe I'll save that for another time and just merge this PR.

[itzg]

I found some ideas for PR-driven test image building; however, I'll experiment with that separately.