[Change Proposal] Add a new discovery parameter that allows any key / value pair to be set

[jlind23]

Currently, content packages are allowed to define different fields to allow for discovery and since #919 it also allows datasets names to be set.

The goal of this issue is to add another parameter to allow discovering packages based on any key / value pairs that could be provided.

Example of how this new parameter could be defined in the manifest:

discovery:
  fields:
    - name: host.ip
       value: xx
  datasets:
    - name: nginx.access

Use Cases

RUM

RUM data is coming from OTel SDKs, hence all the data lands in traces-generic.otel-default.
To allow auto-install of a RUM content pack, we would need the possibility to check for the telemetry.sdk.name field to contain the value webjs.

Data from generic OTel Collector Receivers

Data from generic receivers (e.g. prometheusreceiver) would land in a dataset like prometheusreceiver.otel. However, that data may contain metrics from different kind of technologies. To auto-install a content pack for a specific technology in the prometheus metrics, we might need something similar as the above as well.

Requirements

• Add new discovery parameter discovery.fields.value.
• Value field is optional, if not provided it will check for existence of the field, otherwise check for the specific value

[jlind23]

Poke @mrodm @kpollich @AlexanderWert

[kpollich]

@jlind23 Is this an urgent ask? Who can I talk to to figure out the relative priority level of this?

cc @nimarezainia

[jlind23]

This came out of a conversation I had with @AlexanderWert about our RUM use case. This is NOT an urgent ask per say but it will allow us to build a better UX for our RUM use case.
@AlexanderWert might give more info about the level of priority.

[AlexanderWert]

This came out of a conversation I had with @AlexanderWert about our RUM use case. This is NOT an urgent ask per say but it will allow us to build a better UX for our RUM use case.
@AlexanderWert might give more info about the level of priority.

For now we will start without auto-install for the content pack for RUM, so it's not a super urgent ask.
But, if not too complicated would be good to work on it in the next couple of months.