001/*
002 * (C) Copyright 2020 Nuxeo (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     bdelbosc
018 */
019package org.nuxeo.runtime.metrics.reporter;
020
021import java.io.IOException;
022import java.util.Collections;
023import java.util.Map;
024import java.util.Set;
025
026import org.apache.logging.log4j.LogManager;
027import org.apache.logging.log4j.Logger;
028import org.nuxeo.runtime.metrics.AbstractMetricsReporter;
029
030import io.dropwizard.metrics5.MetricAttribute;
031import io.dropwizard.metrics5.MetricFilter;
032import io.dropwizard.metrics5.MetricRegistry;
033import io.opencensus.contrib.dropwizard5.DropWizardMetrics;
034import io.opencensus.exporter.stats.prometheus.PrometheusStatsCollector;
035import io.opencensus.metrics.Metrics;
036import io.prometheus.client.exporter.HTTPServer;
037
038/**
039 * Reports metrics to Prometheus.
040 *
041 * @since 11.1
042 */
043public class PrometheusReporter extends AbstractMetricsReporter {
044
045    private static final Logger log = LogManager.getLogger(PrometheusReporter.class);
046
047    protected static final int DEFAULT_PORT = 9090;
048
049    protected int port;
050
051    protected int zPort;
052
053    protected HTTPServer server;
054
055    @Override
056    public void init(long pollInterval, Map<String, String> options) {
057        super.init(pollInterval, options);
058        port = getOptionAsInt("port", DEFAULT_PORT);
059    }
060
061    @Override
062    public void start(MetricRegistry registry, MetricFilter filter, Set<MetricAttribute> deniedExpansions) {
063        log.warn("Creating Prometheus endpoint on port {}", port);
064        DropWizardMetrics registries = new DropWizardMetrics(Collections.singletonList(registry), filter);
065        Metrics.getExportComponent().getMetricProducerManager().add(registries);
066        try {
067            PrometheusStatsCollector.createAndRegister();
068        } catch (IllegalArgumentException e) {
069            log.warn("Prometheus collector already registered");
070        }
071        try {
072            server = new HTTPServer(port, true);
073        } catch (IOException e) {
074            throw new IllegalArgumentException("Cannot start Prometheus on port " + port, e);
075        }
076    }
077
078    @Override
079    public void stop() {
080        log.debug("Stop reporting");
081        server.stop();
082        server = null;
083    }
084
085}