Custom extension similar to headers setter not setting client metadata

[varkey98]

Component(s)

extension/headerssetter

Describe the issue you're reporting

I'm trying to write an extension similar to header setter extension, but in my extension I'm not able to see any client metadata. Attaching my code, would greatly appreciate some help

extension code:

package authenticator

import (
	"context"
	"go.opentelemetry.io/collector/client"
	"go.opentelemetry.io/collector/component"
	"go.opentelemetry.io/collector/extension/auth"
	"google.golang.org/grpc/credentials"
	"net/http"
)

// type assertion
var _ auth.Client = (*Authenticator)(nil)

type Authenticator struct {
	// noop start
	component.StartFunc
	// noop shutdown
	component.ShutdownFunc
}

func (a *Authenticator) RoundTripper(base http.RoundTripper) (http.RoundTripper, error) {
	return newRoundTripper(base), nil
}

func (a *Authenticator) PerRPCCredentials() (credentials.PerRPCCredentials, error) {
	return &rpcCredentials{}, nil
}

var _ http.RoundTripper = (*roundTripper)(nil)

type roundTripper struct {
	delegate http.RoundTripper
}

func newRoundTripper(delegate http.RoundTripper) http.RoundTripper {
	return &roundTripper{delegate: delegate}
}

func (r *roundTripper) RoundTrip(request *http.Request) (*http.Response, error) {
	cl := client.FromContext(request.Context())
	vals := cl.Metadata.Get("agent-token")
	if len(vals) > 0 {
		request.Header.Add("agent-token", vals[0])
	}
	return r.delegate.RoundTrip(request)
}

var _ credentials.PerRPCCredentials = (*rpcCredentials)(nil)

type rpcCredentials struct {
}

func (r rpcCredentials) GetRequestMetadata(ctx context.Context, _ ...string) (map[string]string, error) {
	cl := client.FromContext(ctx)
	ret := make(map[string]string)
	vals := cl.Metadata.Get("agent-token")
	if len(vals) > 0 {
		ret["agent-token"] = vals[0]
	}
	return ret, nil
}

func (r rpcCredentials) RequireTransportSecurity() bool {
	return false
}

[github-actions]

Pinging code owners:

• extension/headerssetter: @jpkrohling

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[varkey98]

Adding on that with the original header setter extension, I'm able to see the headers, but only with otlp http exporter. On otlp trace exporter, I didnt see it added on the server metadata

[varkey98]

Found the issue, closing this and opening another with a better description