ed4fc75758
### Added - Support `OTEL_EXPORTER_OTLP_LOGS_INSECURE` and `OTEL_EXPORTER_OTLP_INSECURE` environments in `go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc`. (#5739) - The `WithResource` option for `NewMeterProvider` now merges the provided resources with the ones from environment variables. (#5773) - The `WithResource` option for `NewLoggerProvider` now merges the provided resources with the ones from environment variables. (#5773) - Add UTF-8 support to `go.opentelemetry.io/otel/exporters/prometheus`. (#5755) ### Fixed - Fix memory leak in the global `MeterProvider` when identical instruments are repeatedly created. (#5754) - Fix panic instruments creation when setting meter provider. (#5758) - Fix panic on instruments creation when setting meter provider. (#5758) - Fix an issue where `SetMeterProvider` in `go.opentelemetry.io/otel` might miss the delegation for instruments and registries. (#5780) ### Removed - Drop support for [Go 1.21](https://go.dev/doc/go1.21). (#5736, #5740, #5800)
"Passthrough" setup for OpenTelemetry
Some Go programs may wish to propagate context without recording spans. To do this in OpenTelemetry, simply install TextMapPropagators, but do not install a TracerProvider using the SDK. This works because the default TracerProvider implementation returns a "Non-Recording" span that keeps the context of the caller but does not record spans.
For example, when you initialize your global settings, the following will propagate context without recording spans:
// Setup Propagators only
otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))
But the following will propagate context and create new, potentially recorded spans:
// Setup SDK
exp, _ := stdout.New(stdout.WithPrettyPrint())
tp = sdktrace.NewTracerProvider(
sdktrace.WithBatcher(exp),
)
otel.SetTracerProvider(tp)
// Setup Propagators
otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))
The Demo
The demo has the following call structure:
Outer -> Passthrough -> Inner
If all components had both an SDK and propagators registered, we would expect the trace to look like:
|-------outer---------|
|-Passthrough recv-|
|Passthrough send|
|---inner---|
However, in this demo, only the outer and inner have TracerProvider backed by the SDK. All components have Propagators set. In this case, we expect to see:
|-------outer---------|
|---inner---|