Docs feedback: Clarify stage.structured_metadata behavior

[marshallford]

URL

https://grafana.com/docs/alloy/latest/reference/components/loki/loki.process/#stagestructured_metadata-block

Feedback

Hello,

A bit of a nitpick, but the phrase "add them to log entries as structured metadata" does not make it obvious that the stage.structured_metadata block in the loki.process component will remove labels. It is almost as if the current behavior could be better described as a "conversion" from labels to structured metadata rather than a "copy" or "add". In fact, it wasn't until I cracked open the source and found this code comment and snippet that I actually understood the goal of the block/stage:

alloy/internal/component/loki/process/stages/structured_metadata.go

Lines 56 to 60 in 67409b5

	// Remove found labels, do this after append to structure metadata
	for _, fl := range foundLabels {
	delete(labels, fl)
	}
	e.Labels = labels

On a related note, a feature request: Could this behavior be configurable? Effectively allow for structured metadata values based on labels, but retain the original values/labels. I can open a seperate GH issue if required.