[Dashboards] CoreDNS dashboard has a wrong job name about helm-charts

[P-n-I]

Looks like other scrapes (node, e.g. kubelet) use relabelConfigs to ensure the job label is concise and consistent so the dashboards can rely on it.
I worked round the issue with :

coreDns:
  spec:
    # ensure consistent job label as dashboard require it
    jobLabel: "jobLabel"

The Service has that label set: https://github.com/VictoriaMetrics/helm-charts/blob/63e41a0585b76a2cc4d113eae290c1401cb48933/charts/victoria-metrics-k8s-stack/templates/servicemonitors/coredns.yaml#L12C5-L12C13

[Haleygo]

@sydorovdmytro Since we don't maintain grafana dashboards ourselves, instead we use this script to sync them from multiple sources like https://github.com/dotdc/grafana-dashboards-kubernetes/tree/master/dashboards.
So you can use what @P-n-I proposed here or modify the dashboard after install.

Another minor suggestion is to add a filter by the cluster label or at least add ad-hoc filters as we have for VM dashboards

It's a good proposal, I think we should propose this to the upstream sources.

[Haleygo]

Related issue dotdc/grafana-dashboards-kubernetes#70

[IvanI3]

Fixed in #823 (imho, making fix in template file same way other services done will be more smoothly)