refactor: use equivalent, shorter Builder.Owns() method

[davidxia]

instead of longer Builder.Watches().

• I've made sure the tests are passing.
• Testing Strategy
  • Unit tests
  • Manual tests
  • This PR is not tested :(

[davidxia]

@kevin85421 @Jeffwan as recent committers/owners of the repo. Very small PR. ~5min to review

docstring for Owns()

// Owns defines types of Objects being *generated* by the ControllerManagedBy, and configures the ControllerManagedBy to respond to
// create / delete / update events by *reconciling the owner object*.  This is the equivalent of calling
// Watches(&source.Kind{Type: <ForType-forInput>}, &handler.EnqueueRequestForOwner{OwnerType: apiType, IsController: true}).

[kevin85421]

LGTM. I am not very familiar with controller-runtime, so cc @DmitriGekhtman @architkulkarni for more reviews.

• docstring mentioned by @davidxia
• For me, Owns has a better compatibility with the master branch of controller-runtime than Watches. See [Question] Is IsController compatible with the master branch? kubernetes-sigs/controller-runtime#2140 for more details.

[davidxia]

Owns() is also already being used in rayservice_controller.go

[DmitriGekhtman]

This is valid.

The Watches on Events looks a little different -- what's going on there?

[davidxia]

The Watches on Events looks a little different -- what's going on there?

Not sure. I left that line as is. Looks like it's listening for all events and was added in #294. More details in that PR.

Added Event reconcile function so that in case of Readiness Probe failure, we can try to recover head or worker node if possible

[DmitriGekhtman]

Test failures due to known flakiness.