@Override
    public void record(RequestMetric metric) {
        doRequestsCtr(requestsCtr, metric);
        doRequestDuration(metric);

        if (metric.isError()) {
            doRequestsCtr(errorsCtr, metric);
        }

        if (metric.isFailure()) {
            doFailureCtr(metric);
        }
    }
Prometheus scrape metrics.

Config:
<ul>
  <li>port - port for web-server to listen on for scrape requests</li>
</ul>

@author Marc Savy {@literal <msavy@redhat.com>}
gateway/engine/prometheus/src/main/java/io/apiman/gateway/engine/prometheus/PrometheusScrapeMetrics.java