Proposal: FieldConfig for Extract Labels from Name

[kylebrandt]

What would you like to be added:
A property added to FieldConfig, that instructs consumers that they can/should extract dimensions (create labels) from the field name.

Why is this needed:
Some data is like this, in SSE (so it works with alerting and Recorded Queries), we have a hack that does this (somehow?) if the DS Type matches (Currently Graphite, but adding Dynatrace soon.

Adding this as a FieldConfig:

• allows control of this behavior to belong to the data source which better understands the data
• Allows DS authors to apply this only to certain responses (more fine grained)
• Easier to debug since the frame will declare that the data can be treated this way

vNext could include an additional property that guides how to extract dimensions/labels, (e.g. { "delim": ".", "keys": ["metric", "namespace", "pod"] }.

• (Maybe Frame Meta could work as well if want applied to all numeric fields perhaps, depends on how fine grained we want the control - frame wide or field specific)

Reference: grafana/grafana#90246 (comment)

cc @yuri-tceretian @yesoreyeram @ryantxu

[ryantxu]

I think this makes sense.

[yesoreyeram]

I like the idea. But in practice, ds authors don't know the mapping of the fields. Also It will be tiresome for a customer to enter all the field mapping manually. for every metric this will be different even though they may be of same length.

[yesoreyeram]

I appd we are doing something similar where we don't know the mapping but the delimiter. So the label goes like segment_1, segment_2.

https://github.com/grafana/plugins-private/blob/53be67e0d9e4bb3e9b3ec9e458d8d7e5763c68d8/plugins/dlopes7-appdynamics-datasource/pkg/appd/metrics/multi_framer.go#L105