Allow regex to keep for promql/aggregate

[leagueofsoups]

Hey! Can you please allow regex to be used for "keep"? My prometheus uses a webhook to send alerts to corporate monitoring, it expects to receive alerts with at least one label from the set.

For example:

rule {
  match {
    kind = "alerting"
  }

  aggregate ".+" {
    keep = ["lable1|lable2"]
  }
}

more information:

Is there a way to check label by regex in the resulting vector, like promql/series (api request)? (after aggregating and adding additional labels)

I whant find alerts WITHOUT special_label

#situation 1:

- name: "<name>"
  rules:
  - alert: AlertName
    expr: <aggregate expression>
    labels:
      special_label: ...

#situation 2:

- name: "<name>"
  rules:
  - alert: AlertName
    expr: sum by (special_label)...