reReplaceAll RE flavor

[jangaraj]

Please use formatted text (you can edit your posts and fix that) + you can share code on play golang directly.
Your code: Go Playground - The Go Programming Language doesn’t work, error ./prog.go:12:63: unknown escape Are you really sure that’s correct regex?

Fix: escape \d:
regexp.Compile(".*?var='C'.*?value=(\d+.\d).*var='D'.*?value=(\d+.\d).*")
→
regexp.Compile(".*?var='C'.*?value=(\\d+.\\d).*var='D'.*?value=(\\d+.\\d).*")

BTW: Why you need to all these regex games in the template? Why you just don’t print values in the annotation and print it in the template. Why you are trying it in such complicated way?

Accessing Query Expression Results for Custom Notification Templates in Managed Grafana Alerts

so B value(s) will be {{ index $values "B" }} or {{ $values.B }}. But this is not a task for notification template. You should use it in the alert annotation, e.g. meaningful description: Pod: {{ $labels.container }} in namespace: {{ $labels.namespace }} on cluster: {{ $labels.kubernetes_cluster }} has high CPU utilization: {{ humanize $values.B.Value }}% and notification template just use that annotation.

Here is source code for that reReplaceAll, so it is Golang definitely:

prometheus/prometheus/blob/release-2.21/template/template.go#L149-L152