input/otlp: record map-type attributes

[axw]

We currently do not record map-type attributes when translating OTLP events to Elastic APM events. For now we may want to flatten the map, adding dots as needed. Hopefully in the future we will be using the Elasticsearch flattened field type, and this will be unnecessary.

[im-aIex]

Any update on this or workarounds? We are attempting to migrate to elastic but it is dropping attributes for some log records that contain complex objects as opposed to simple strings/numbers.

[axw]

@im-aIex the only update (and workaround) to share is that there has been a significant amount of work on improving the OpenTelemetry Collector Elasticsearch exporter. The Elasticsearch exporter does support handling map-type attributes.

As far as workarounds go, you could use that, but bear in mind that:

• the exporter has a mixture of development (read: tech preview) and beta stability
• making the exporter's output compatible with curated Kibana UIs such as the APM UI is a work in progress