Add rulesets instance key

[cognifloyd]

Description

Add a new instance key under step rulesets. This allows a pipeline to skip steps if the pipeline is running on an unexpected vela instance.

Today, we can check VELA_ADDR in step commands to opt-in/out on certain instances. A ruleset that can completely remove irrelevant steps during pipeline compilation would be much better.

Value

I need a Vela instance in the EU, and a different one in the US. Both instances process some of the same repos. Some steps should only run in EU or in US.

I also have seperate dev/prod Vela clusters. Some steps might only apply to one or the other.

Definition of Done

Add new instance yaml key under step.rulesets that allows steps to run only on particular cluster(s).

The instance check happens during pipeline compilation to remove irrelevant steps.

Effort (Optional)

unknown

Impacted Personas (Optional)

Users that need to distinguish between multiple Vela instances.

[wass3rw3rk]

this should be in the next version - thanks for the idea ❤️