Regex to remove whitespace at the end of DisplayString metrics

[jp-moller]

I have a vendor that has a variable amount of whitespace at the end of all metrics that are of type DisplayString:

solarChargersCurrentDescription{solarChargersCurrentDescription="Solar current   "} 1
batteryTimeLeftDescription{batteryTimeLeftDescription="BatteryTimeLeft "} 1
batteryTemperaturesDescription{batteryTemperaturesDescription="BatteryTemp     "} 1

Is there a way for me to rewrite these to remove any trailing whitespace? I don't think the regex_extracts method works, as that converts the extracted group to a float64, which doesn't work for strings that are meant to stay as strings.

Any ideas?

[SuperQ]

I had an idea to provide an equivalent to metric_relabel_configs directly in the exporter. But for now you would need to do this in Prometheus.

Something like this:

metric_relabel_configs:
- source_labels:
  - solarChargersCurrentDescription
  regex: "(.+[a-z])\\s*"
  target_label: solarChargersCurrentDescription

[jp-moller]

That would be super handy! Thanks for letting me know.