Co-processes feature request

[yellowmegaman]

I'd like to put this idea up for discussion.

I would be great if a co-process could be tweaked so it starts right away, not waiting for preStart to complete.

Use case:

1. I don't want to run supervisord/runit/s6
2. i want to run consul agent as a co-process
3. preStart has leader election based on consul sessions/keys
4. i want to register sessions against local consul agent so when it leaves, sessions get expired

If i create new session against some consul agent that won't be terminated when container is terminated, session will remain. I don't like all this renew stuff, consul agent leave event is just more efficient.

Is it hard/ok by design to implement?
Something like:

"coprocesses": [
    {
      "name": "consul_agent",
      "command": ["consul", "agent", "etcetera", "etcetera"],
      "restarts": "unlimited",
      "start_after": "init"
    }
  ]

Thanks a lot in advance!

[tgross]

Co-processes are being removed in ContainerPilot v3 in lieu of supporting multiple first-class processes. That is, all the processes will be co-processes. This will allow you to specify dependency chains explicitly (or just start immediately!) just as you're asking for here.

See https://github.com/joyent/rfd/blob/master/rfd/0086/multiprocess.md for the design doc for this and keep an eye on #290 and #283 for progress.

[yellowmegaman]

Awesome! So i'll have to rewrite all my configs 😃
Thanks a lot for info and links!
Hope this feature will land in releases anytime soon)