How do nomad task driver plugins actually work?

[lgfa29]

Hi @tomqwpl

@tomqwpl

I’ve written a custom plugin based on the skeleton example, and it all works fine.

That’s awesome! I would love to hear more about it if you don’t mind

@tomqwpl

However, I still don’t really understand how they actually work, what the lifecycle is, and I can’t really find any good description. I’ve tried reading the code, but so far I’ve failed to gain any real insight.

That’s a very good point, and we certainly need to improve our docs on this. Maybe this presentation can help you understand things better?

Extending Nomad with Plugins

@tomqwpl

Do I end up with one plugin executable running for each task that is launched?

No. Nomad will start one plugin process in each client that has it installed. This process will then be responsible for managing all the tasks.

@tomqwpl

It seems that multiple copies of my plugin are run, but I’m unsure exactly how they are managed and what’s responsible for what

That’s odd

Maybe Nomad was force-quit and didn’t have time to stop the plugin process, and so they accumulated over time? And are they actually your plugin process or maybe a child process that your plugin creates for each task?

Checkout the video I linked and see if it helps you. If your plugin is open source it would nice to have a link as well (if possible).