watchNamespaces improvements

[pepov]

• Make logging.spec.watchNamespaces (explicit static list) and logging.spec.watchNamespaceSelector (label based dynamic list) additive instead of exclusive for hopefully better semantics.
• Add tests for better coverage (looking into reusing the same thing for a different use case as well)
• Add namespace watches and trigger reconcile on loggings with watchNamespaceSelector defined

Signed-off-by: Peter Wilcsinszky peter.wilcsinszky@axoflow.com

[pepov]

@nak0f as we are preparing to build on top of these selectors I wanted to reconsider making the two different namespace lists additive instead of exclusive to reduce frustration of users as they have to debug through the logging resource.

also this adds a few tests to cover the behaviour

[aslafy-z]

Another option would be to remove completely watchNamespaces and encourage users to use the kubernetes.io/metadata.name label (available since 1.22) to select by name. In this case, we may want to allow a list of selectors for watchNamespaceSelector instead of a single selector.

[pepov]

@aslafy-z sounds good (I wasn't aware of that label), but that would be a breaking change affecting lots of users, thus I would avoid it now.

[aslafy-z]

I opened #1394 to track this enhancement proposal.

[siliconbrain]

lgtm