add gauge metric support for signaltometrics connector

[gilad-aperio]

Component(s)

connector/signaltometrics

Is your feature request related to a problem? Please describe.

Many systems, especially legacy ones, report metrics through logs. Analyzing metric data directly from logs is inefficient and complex, which highlights the need to extract it from the logs during collection and store it as a separate signal. This capability already exists on the receiving end of many monitoring platforms (1, 2, 3) - having it in OTel would greatly enhance it.
The signaltometrics connector is a huge step toward this, but it does not produce the gauge metric type currently. This is a request to add gauge to the list of supported produced metrics.

Describe the solution you'd like

Example configuration:

connectors:
  signaltometrics:
    gauge:
      value: ExtractGrokPatterns(body, "%{TIMESTAMP_ISO8601:timestamp} Memory usage: %{NUMBER:memory_mb:float}MB")

Log: 2025-01-08 16:28:00 Memory usage: 600MB
Result:

[
  {
    "timestamp": "2025-01-08 16:28:00",
    "memory_mb": 600
  }
]

Describe alternatives you've considered

No response

Additional context

No response

[github-actions]

Pinging code owners:

• connector/signaltometrics: @ChrsMark @lahsivjar

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[lahsivjar]

Sounds good to me.

[lahsivjar]

/label -needs-triage

[akstron]

Hi @lahsivjar , I would like to work on it. Can you please assign this to me?

[lahsivjar]

@akstron I don't think I have the permission to assign it to you but feel free to create a PR as, to my knowledge, no one is working on this right now.

[oshamin]

I am also interested in this feature, @akstron have you started working on it?

[akstron]

Hi @oshamin , yes I have. Need few days to send out a PR.

[lahsivjar]

👋 @akstron , how is the PR coming along? Let me know if you need any input/help.

[oshamin]

Any update to the PR?

[lahsivjar]

I did a spike on something similar for a separate purpose, and I can polish it to create a PR for this issue, but let's wait for an update from @akstron first.