propagator configuration needs better shorthand

[lizthegrey]

global.SetTextMapPropagator(otel.NewCompositeTextMapPropagator(propagators.TraceContext{}, propagators.Baggage{}))

is impossible for a new user to figure out on their own, and is a magic incantation we should give a mnemonic if we don't just make it the default.

[Aneurysm9]

Agreed. Unfortunately, the spec now requires no-op default propagators. Perhaps we should have a function in the propagators package that returns a composite propagator with TraceContext and Baggage.

[lizthegrey]

agree, a composite out of box propagator would be helpful to have a util function for.

[seanschade]

I will give you my experience from a user's point of view. I implemented this yesterday in one of our shared libraries and found it to be quite intuitive.

We plan to create one or more custom propagators, and otel.NewCompositeTextMapPropagator(...) is an easy way to set them when initializing the telemetry. I created a map to help parse the OTEL_PROPAGATORS environment variable and set the global propagators.

var SupportedTextMapPropagators = map[string]otel.TextMapPropagator{
		"baggage":      propagators.Baggage{},
		"tracecontext": propagators.TraceContext{},
		"b3":           b3.B3{},
		"jaeger":       jaeger.Jaeger{},
}