Dropwizard metrics are not exported in simpleclient_vertx or simpleclient_vertx4 #780
Description
Using DropwizardExports doesn't work with neither simpleclient_vertx nor simpleclient_vertx4.
The Vertx handler calls CollectorRegistry.filteredMetricFamilySamples which returns an enumeration of collectors from CollectorRegistry.namesToCollectors.
DropwizardExports implements Collector.Describable but it's describe method returns an empty List<MetricFamilySamples> so nothing is added to the CollectorRegistry.namesToCollectors when it's registered. However, the empty list of names does get added to CollectorRegistry.collectorsToNames which is how I was able to go around this issue for the time being.
Right now the only way I was able to export the Dropwizard metrics was by calling CollectorRegistry.metricFamilySamples which uses the CollectorRegistry.collectorsToNames.