I am using the OpenTelemetry library in my .NET application to collect logs, which are sent to Grafana Alloy. Grafana Alloy then forwards these logs to Grafana Loki. I need help mapping specific log attributes (e.g., service.name, environment, or other custom attributes) to Loki label filters. How …

Looks like nested JSON? Try this (not tested): loki.write “default” { endpoint { url = “http://loki:3100/loki/api/v1/push” } } loki.process "local" { forward_to = [loki.write.“default”.receiver] stage.json { expressions = { attributes = "", } } stage.json { sour…

I am pretty sure if a key doesn’t exist it would be assigned null value, which when sent to Loki would simply not exist as a label. I’d recommend you to test it out.

Are you suggesting that all potential attributes should be specified in the Alloy configuration?

No, I do not suggest you to turn all potential attributes into labels. Only pick the ones you need. See Loki’s label best practices here: Label best practices | Grafana Loki documentation

Thank you for your suggestion; it means a lot. Is there a way to convert all attributes into Loki labels?

I don’t believe there is a way to dynamically do it. I haven’t had to do this, since it’s generally a bad idea because you do want to limit on number of labels and their potential values.

I think a better approach would be to use: ‘otelcol.processor.attributes’ with key=”loki.attribute.labels”. Best check this example: otelcol.exporter.loki | Grafana Agent documentation

The question was for alloy. The doc you point to is grafana agent

My bad I put the wrong link: otelcol.exporter.loki | Grafana Alloy documentation I just did it for Alloy.

How to Map Log Attributes to Loki Label Filters with Grafana Alloy?

Grafana Alloy

dedavidsilwal January 22, 2025, 4:06am 3

Thank you for your guidance; I truly appreciate it. Could you please provide instructions on handling logs where the attributes are dynamic and not fixed?

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How to Map Log Attributes to Loki Label Filters with Grafana Alloy?

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