/*
 * Copyright 2018 Red Hat, Inc. and/or its affiliates
 * and other contributors as indicated by the @author tags.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.vertx.micrometer.backends;

import io.micrometer.core.instrument.Meter;
import io.micrometer.core.instrument.MeterRegistry;
import io.micrometer.core.instrument.config.MeterFilter;
import io.micrometer.core.instrument.distribution.DistributionStatisticConfig;
import io.micrometer.prometheus.PrometheusConfig;
import io.micrometer.prometheus.PrometheusMeterRegistry;
import io.prometheus.client.exporter.common.TextFormat;
import io.vertx.core.Vertx;
import io.vertx.core.http.HttpHeaders;
import io.vertx.core.http.HttpServerOptions;
import io.vertx.core.http.HttpServerRequest;
import io.vertx.core.logging.Logger;
import io.vertx.core.logging.LoggerFactory;
import io.vertx.micrometer.VertxPrometheusOptions;

Author:Joel Takvorian
/** * @author Joel Takvorian */
public final class PrometheusBackendRegistry implements BackendRegistry { private static final Logger LOGGER = LoggerFactory.getLogger(PrometheusBackendRegistry.class); private final PrometheusMeterRegistry registry; private final VertxPrometheusOptions options; private Vertx vertx; public PrometheusBackendRegistry(VertxPrometheusOptions options) { this(options, new PrometheusMeterRegistry(PrometheusConfig.DEFAULT)); } public PrometheusBackendRegistry(VertxPrometheusOptions options, PrometheusMeterRegistry registry) { this.options = options; this.registry = registry; if (options.isPublishQuantiles()) { registry.config().meterFilter( new MeterFilter() { @Override public DistributionStatisticConfig configure(Meter.Id id, DistributionStatisticConfig config) { return DistributionStatisticConfig.builder() .percentilesHistogram(true) .build() .merge(config); } }); } } @Override public MeterRegistry getMeterRegistry() { return registry; } @Override public void init() { if (options.isStartEmbeddedServer()) { this.vertx = Vertx.vertx(); // Start dedicated server HttpServerOptions serverOptions = options.getEmbeddedServerOptions(); if (serverOptions == null) { serverOptions = new HttpServerOptions(); } vertx.createHttpServer(serverOptions) .requestHandler(this::handleRequest) .exceptionHandler(t -> LOGGER.error("Error in Prometheus registry embedded server", t)) .listen(serverOptions.getPort(), serverOptions.getHost()); } } private void handleRequest(HttpServerRequest request) { if (options.getEmbeddedServerEndpoint().equals(request.path())) { request.response() .putHeader(HttpHeaders.CONTENT_TYPE, TextFormat.CONTENT_TYPE_004) .end(registry.scrape()); } else { request.response().setStatusCode(404).end(); } } @Override public void close() { if (this.vertx != null) { vertx.close(); } } }