FailOnSharedResource enhancement proposal

[wilsonwang371]

Summary

Suggesting changing FailOnSharedResource default to true if not specified. Also, add start up option to enforce FailOnSharedResource.

Motivation

Recently, we got an high priority issue in our production environment. Some users accidentally created shared resources due to a code copy & paste. Finally, the resource was deleted when one of the applications was removed. In a multi-user environment, we may need to enforce failing on shared resources.

Proposal

I suggest there need to be 2 changes.

1. Make FailOnSharedResource default to true if not specified.
2. Add a startup option so that FailOnSharedResource=true can be enforced no matter what is specified in the application CR.

I can submit a patch for these 2 changes.

[kamalmarhubi]

@jannfis can you weigh in on whether you prefer the command line argument approach suggested here and implemented in #17764 or the AppProject approach you suggested in #10144 that was started on in #17203?

Would love to see some way to do this, as we've had at least once incident caused by uncareful setting of a namespace for an application resulting in shared resources.

cc @crenshaw-dev as you seem to be more recently active on the repo!

[kamalmarhubi]

@alexmt since you read this and are also a more recently active contributor, do you have an opinion on this? I don't know if @wilsonwang371 is still interested in merging this, but I'd be willing to adapt their work some time in the next few weeks in order to get this into an upcoming release.

(In case it helps figuring out the preferred location for this setting, I'm also interested in enforcing that we use server side apply everywhere.)