Collector and http client port mismatch

[doggan]

Description

otlptracehttp client defaults to port 4317, but collector spec says http uses 4318. (4317 is for grpc).

• opentelemetry-go/exporters/otlp/otlptrace/otlptracehttp/options.go

  Line 58 in bd817df

  // the default endpoint (localhost:4317). Note that the endpoint

• https://github.com/open-telemetry/opentelemetry-collector/blob/fb1539f7e57b782c2419115c602fff9a356040db/receiver/otlpreceiver/README.md#getting-started
  • endpoint (default = 0.0.0.0:4317 for grpc protocol, 0.0.0.0:4318 http protocol):,

Environment

	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.4.0
	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.4.0
	go.opentelemetry.io/otel/sdk v1.4.0
	go.opentelemetry.io/otel/trace v1.4.0

Steps To Reproduce

1. N/A

Expected behavior

I would expect the http client to default to port 4318, such that it is aligned with the port expected by the collector.

[MrAlias]

The OpenTelemetry specification also states the port 4318 should be used as the default for HTTP.

This is currently unified in the internal/otlpconfig package.

opentelemetry-go/exporters/otlp/otlptrace/internal/otlpconfig/optiontypes.go

Line 20 in 1bda062

DefaultCollectorPort uint16 = 4317

It will need to be refactored to support different default values for the different clients.