Allow negative --idle-timeout on cml-runner

[0x2b3bfa0]

See iterative/cml.dev#91 (comment); using 0 to convey disabled is not especially friendly, numerically speaking.

[casperdcl]

should we also change RUNNER_IDLE_TIMEOUT = 5 * 60 to actually be -1 if we're not in GH/GL/BB?

[0x2b3bfa0]

@casperdcl, do you intend to automate the default value to detect if it has been launched by humans or if it's just an ad-hoc runner launched by a previous step in a workflow? It looks like a good idea, but having too many different defaults could also confuse users.

[casperdcl]

We already do custom checks for e.g. cml.driver == 'github' to retry before 72h. I think the point of CML is precisely this sort of convenient default config.

"Seconds to wait for jobs before shutting down. Default: 300 in CI or -1 (disabled) otherwise."

[0x2b3bfa0]

Yes, CML already has a fair amount of moving parts to infer whether it's running on a CI/CD platform or not, which platform it's running on and quite a few other things that try to offload as much choices as possible from users.

This could be nice if it's what users expect, but promising a default value when running cml-runner --help locally and doing something completely different on the cloud could be less boring than what we would desire.

[0x2b3bfa0]

It wouldn't be the first time we take a choice based on the environment, but altering a default value still is a bit risky, even if we document it.

[0x2b3bfa0]

I'm inclined to think that the cloud use case is the prevalent one and the few users that want to use cml-runner on-premises can afford typing a few characters more.

Is that extra option on the documentation verbose enough to be replaced by "smart" code? iterative/cml.dev#93 (comment)

[DavidGOrtega]

👍 lgtm

[casperdcl]

@DavidGOrtega what about #700 (comment) / #700 (comment)?

[DavidGOrtega]

@casperdcl I think is a nice idea butI wonder how many breaks introduces. As I stated I launch self hosted GPU runners (2 titans) and expect to shutdown the machine after no more jobs. Its not a big deal, but that makes me think that the change is not really needed since:

• it behaves the same in cloud or other env
• maybe we are introducing a riddle to some users