Motivation

The Extended Observability RFC revision 25 requires us to record db.couchbase.cluster_name and db.couchbase.cluster_uuid in all spans created by the SDK.

Changes

• Create a new core::tracing::tracer_wrapper class that watches for config updates and keeps track of cluster labels. We can expand is in the future to DRY creation of certain types of spans that we need to add (request_encoding, dispatch_to_server).
• All spans created from the core, are created via the wrapper which always adds the db.system tag and the cluster labels if those are exposed by the cluster. All spans should have these 3 tags.
• Replace all tracer references in the core with the tracer wrapper
• Update assertions in tracing tests to check for db.system and cluster labels

Results

Tests pass