org.springframework.boot.actuate.metrics.export.prometheus.PrometheusScrapeEndpoint Maven / Gradle / Ivy
/*
* Copyright 2012-2018 the original author or authors.
*
* 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
*
* https://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 org.springframework.boot.actuate.metrics.export.prometheus;
import java.io.IOException;
import java.io.StringWriter;
import java.io.Writer;
import io.prometheus.client.CollectorRegistry;
import io.prometheus.client.exporter.common.TextFormat;
import org.springframework.boot.actuate.endpoint.annotation.Endpoint;
import org.springframework.boot.actuate.endpoint.annotation.ReadOperation;
import org.springframework.boot.actuate.endpoint.web.annotation.WebEndpoint;
/**
* {@link Endpoint} that outputs metrics in a format that can be scraped by the Prometheus
* server.
*
* @author Jon Schneider
* @since 2.0.0
*/
@WebEndpoint(id = "prometheus")
public class PrometheusScrapeEndpoint {
private final CollectorRegistry collectorRegistry;
public PrometheusScrapeEndpoint(CollectorRegistry collectorRegistry) {
this.collectorRegistry = collectorRegistry;
}
@ReadOperation(produces = TextFormat.CONTENT_TYPE_004)
public String scrape() {
try {
Writer writer = new StringWriter();
TextFormat.write004(writer, this.collectorRegistry.metricFamilySamples());
return writer.toString();
}
catch (IOException ex) {
// This actually never happens since StringWriter::write() doesn't throw any
// IOException
throw new RuntimeException("Writing metrics failed", ex);
}
}
}