Flow: Alternative to Static mode's tracing automatic_logging processor

[ptodev]

Request

The traces config in Static mode contains an automatic_logging processor which can create log lines from traces. This is similar to otelcol.exporter.logging, but more flexible in some ways:

• The log output could be sent to Loki, whereas otelcol.exporter.logging can only write to console
• automatic_logging could log a line per span, root, or process.
• Overrides for Loki log labels

Additionally, it was reported that viewing output of otelcol.exporter.logging can be awkward since it outputs \n inside the message, which forces people to paste the message in an editor and replace the line breaks.

I am not sure how the automatic_logging processor is used by customers and how important all those features are. If we want to integrate with Loki or to have the additional filtering on span/root/process, then we could create a new component. The new component could output Otlp-formatted logs, and then this could be piped to otelcol.exporter.loki and loki.write?

This new component would be a bit like Otel's spanmetrics connector, but instead of metrics it would create logs out of the traces. AFAIK there is no such component planned for the Collector yet.

Use case

Flow feature parity.