Ability to use action:extract on metrics labels/attributes values.

[cbackstrom80]

We need the ability to be able to extract on "Metrics" attributes/label values similar to that available to spans in the attributes processor.

Non Working Example:

resource/storeid: attributes: - key: "keyname" action: extract pattern: ^(?P<siteid>[A-Z][0-9]+)-[A-Z0-9]+$$

Describe the solution you'd like
We would like to be able to have a processor create a new key with a modified value from another key/label/attribute.

Describe alternatives you've considered
We have tried metrics transform processor but can only use regex functionality on pattern match.

Additional context
Some of the blockers might also be due the fact that we are trying to work with "Data Point Attributes" coming from collected.

     -> Unit:
     -> DataType: Gauge
 NumberDataPoints #0
 Data point attributes:
      -> user_domain_name: STRING(default)
    -> region_name: STRING(region)
     -> project_domain_name: STRING(default)
    -> system.type: STRING(openstack)
    -> dsname: STRING(value)
     -> status: STRING(enabled)
     -> hypervisor_hostname: STRING(hostname)
    -> plugin: STRING(openstack)
    -> project_name: STRING(S7675)
     -> project_id: STRING(347dafc5aca04c20bcbc4eeb0118ce53)
    -> state: STRING(up)
     -> hypervisor_type: STRING(QEMU)
      -> id: STRING(241)
      -> host_ip: STRING(123.123.123.123)

[bogdandrutu]

@anuraaga your transform processor will support this correct?

[aunshc]

@anuraaga @bogdandrutu is this the design document #4444 being referred to for the implementation of the transform processor that will support the above use case?

[anuraaga]

Sorry for delayed response - yes that's the design doc and this will be supported once adding metrics support to it.

[bogdandrutu]

I believe that this is supported by the transform processor.
/cc @TylerHelmuth if more work is needed, please open an issue in contrib

[TylerHelmuth]

The processor is ready to have this functionality added, but there isn't a function yet that can do this exact request. Attributes can be set on Data Points, but there is not any pattern matching yet.