Auth-context available for use in export-config

[DennisGlindhart]

When using a (Server)Authentication extension for OTEL-Collector (i.e. basic auth, oidc etc. from contrib), I would like it to be possible to somehow extract the username (or other auth-data/claim) and use it in i.e. exporter-headers.

The auth context seems to be returned from the extension in authenticate-method ( https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/extension/oidcauthextension/extension.go#L136 ) so it should already be available in the context.

Describe the solution you'd like
Ability to use the auth context in exporter-config.

exporters:
  otlp:
    headers:
      x-scope-orgid: <USERNAME FROM AUTH>

Additional context
One use case here could be to have only a singe OTEL-collector running on multitenant server/cluster-node etc and let software authenticate with the OTEL-collector and be exported with Multitentenancy-header (in this example Scope-header used Grafana Tempo/Loki).

[jpkrohling]

@bogdandrutu, @tigrannajaryan, do you think we could change the confighttp to accept a notation like context.user_id, which would make it look up the user_id key within the context? Or perhaps you have another suggestion? In any case, I would do it after GA.

[tigrannajaryan]

use it in i.e. exporter-headers.

@jpkrohling how will this work? We don't maintain the context in batch processor or in queued_retry, so the incoming context won't be available in the exporters, right?

[jpkrohling]

We don't yet, but I do plan on working on that soon (#4544).

[bogdandrutu]

@tigrannajaryan we do maintain the context in queued_retry only in batching we have a problem, since we batch requests from multiple sources.

[kovrus]

@DennisGlindhart does open-telemetry/opentelemetry-collector-contrib#12892 resolve this issue for you?

[DennisGlindhart]

@kovrus Reading the README it would seem so, yes.

This configuration should fill the username from auth into User-ID header when sending to exporter if I understand correctly.

extensions:
  headers_setter:
    headers:
      - key: User-ID
        from_context: "user_id"

There is still the batch-limitation (Nice to have), but I guess in the future relying on the same work mentioned earlier could solve that? (#4544).

[kovrus]

There is still the batch-limitation (Nice to have), but I guess in the future relying on the same work mentioned earlier could solve that? (#4544).

That's correct. See #5733 (comment), it could be potentially temporal workaround.

@jpkrohling can you please close this issue?