fix wrong namespaceSelector in servicemonitor

[tulequ]

Why is this pull request needed and what does it do?

when set prometheus.monitor.namespace to differ namespace, we should use namespaceSelector to specify service namespace

Which issues (if any) are related?

Checklist:

• I have bumped the chart version according to versioning.
• I have updated the chart changelog with all the changes that come with this pull request according to changelog.
• Any new values are backwards compatible and/or have sensible default.
• I have signed off all my commits as required by DCO.

Changes are automatically published when merged to main. They are not published on branches.

Note on DCO

If the DCO action in the integration test fails, one or more of your commits are not signed off. Please click on the Details link next to the DCO action for instructions on how to resolve this.

[hagaibarel]

Not sure I understand the change, shouldn't the namespace selector always be the release namespace? In what cases should the service monitor be targeting a different namespace?

[tulequ]

Because some prometheus is deployed with servicemonitor namespace to monitoring only (I don't think it is good, but it is historical)

I give some example
https://github.com/kubernetes/ingress-nginx/blob/main/charts/ingress-nginx/templates/controller-servicemonitor.yaml#L31-L37 (this is complex :)) )
https://github.com/bitnami/charts/blob/main/bitnami/redis/templates/servicemonitor.yaml#L43-L45
https://github.com/bitnami/charts/blob/main/bitnami/rabbitmq/templates/servicemonitor.yaml#L51-L53

[hagaibarel]

Alright, sounds reasonable, please fill out all the items in the PR checklist and we can get this rolling (e.g. DCO)

[hagaibarel]

@tulequ the DCO check is failing, please resolve

[hagaibarel]

Seems like the DCO check is still failing, please fix so we can merge this

[tulequ]

please check again

[hagaibarel]

Thanks!