project  string
}

func (c *meshAuthCredentials) GetRequestMetadata(ctx context.Context, uri ...string) (map[string]string, error) {
	ret := map[string]string{
		"x-goog-user-project": c.project,
	}
	if err := updateAuthHdrs(ctx, uri, "k8s", c.k8sCreds, ret, "x-mesh-authorization"); err != nil {
		return nil, err
	}
	if err := updateAuthHdrs(ctx, uri, "gcp", c.gcpCreds, ret, "authorization"); err != nil {
		return nil, err
	}

	// A bit inexact but should be good enough.
	return strings.Contains(addr, ".googleapis.com/") || strings.Contains(addr, ".googleapis.com:443/")
}

func mcpTransport(ctx context.Context, tr http.RoundTripper) (http.RoundTripper, error) {
	creds, err := google.FindDefaultCredentials(ctx, "https://www.googleapis.com/auth/cloud-platform")
	if err != nil {
		return nil, fmt.Errorf("finding default GCP credentials: %w", err)
	}
	return &oauth2.Transport{