RFE: singleton mode for the controller

[dtantsur]

In tightly controlled environments such as OpenShift, it's preferred to lock the Ironic controller to only reconcile one named object in one namespace. The namespace limit can already be achieved using the WATCH_NAMESPACE environment variable. We need something similar for the object name, something like SINGLETON_NAME (suggestions welcome).

/kind feature
/triage accepted
/help

[metal3-io-bot]

@dtantsur:
This request has been marked as needing help from a contributor.

Please ensure the request meets the requirements listed here.

If this request no longer meets these requirements, the label can be removed
by commenting with the /remove-help command.

In response to this:

In tightly controlled environments such as OpenShift, it's preferred to lock the Ironic controller to only reconcile one named object in one namespace. The namespace limit can already be achieved using the WATCH_NAMESPACE environment variable. We need something similar for the object name, something like SINGLETON_NAME (suggestions welcome).

/kind feature
/triage accepted
/help

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.