Have a way to disable the legacy HTTP endpoint

[rgl]

Describe the bug

There is no way to disable the legacy HTTP endpoint.

This behavior seems to be hardcoded without a way to disable.

Steps to reproduce

When using this library from Tempo, I've explicitly set the HTTP endpoint as:

distributor:
  receivers:
    # see https://github.com/grafana/tempo/blob/v1.2.1/modules/distributor/config.go#L33
    # see https://github.com/open-telemetry/opentelemetry-collector/tree/main/receiver/otlpreceiver
    otlp:
      protocols:
        http:
          endpoint: 0.0.0.0:4318

What did you expect to see?

Only port 4318 listening.

What did you see instead?

It also opens the legacy HTTP listener at port 55681.

What version did you use?

I'm using it tru Tempo 1.2.1. I think its using v0.21.0:

• https://github.com/grafana/tempo/blob/v1.2.1/go.mod#L57
• https://github.com/grafana/tempo/blob/v1.2.1/go.sum#L2065-L2066

Also note that the latest collector version (v0.41.0) also uses the same code, so I guess it also has the same behavior.

What config did you use?

See the description.

Environment

OS: Ubuntu 20.04
Compiler(if manually compiled): N/A.

Additional context

Originally asked for help at grafana/tempo#1181

[jpkrohling]

Interesting, I thought we enabled it only when no values were explicitly provided. I think it might be time to remove this anyway... Thoughts from other approvers and maintainers?

cc @open-telemetry/collector-maintainers , @open-telemetry/collector-approvers

[tigrannajaryan]

Let's remove legacy ports completely. I think we kept it in grace period for long enough.