Support OpenMetrics text format with Prometheus

Update `PrometheusScrapeEndpoint` so that it can produce both classic
Prometheus text output as well as Openmetrics output.

See gh-25564
This commit is contained in:
Andy Wilkinson 2021-03-18 19:11:02 -07:00 committed by Phillip Webb
parent c81a0223cc
commit 11b4a19dee
5 changed files with 101 additions and 8 deletions

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@ -16,6 +16,15 @@ The resulting response is similar to the following:
include::{snippets}/prometheus/all/http-response.adoc[]
The default response content type is `text/plain;version=0.0.4`.
The endpoint can also produce `application/openmetrics-text;version=1.0.0` when called with an appropriate `Accept` header, as shown in the following curl-based example:
include::{snippets}/prometheus/openmetrics/curl-request.adoc[]
The resulting response is similar to the following:
include::{snippets}/prometheus/openmetrics/http-response.adoc[]
[[prometheus-retrieving-query-parameters]]

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@ -1,5 +1,5 @@
/*
* Copyright 2012-2020 the original author or authors.
* Copyright 2012-2021 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.
@ -20,6 +20,7 @@ import io.micrometer.core.instrument.Clock;
import io.micrometer.core.instrument.binder.jvm.JvmMemoryMetrics;
import io.micrometer.prometheus.PrometheusMeterRegistry;
import io.prometheus.client.CollectorRegistry;
import io.prometheus.client.exporter.common.TextFormat;
import org.junit.jupiter.api.Test;
import org.springframework.boot.actuate.metrics.export.prometheus.PrometheusScrapeEndpoint;
@ -31,6 +32,7 @@ import static org.springframework.restdocs.mockmvc.MockMvcRestDocumentation.docu
import static org.springframework.restdocs.request.RequestDocumentation.parameterWithName;
import static org.springframework.restdocs.request.RequestDocumentation.requestParameters;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.header;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
/**
@ -46,6 +48,14 @@ class PrometheusScrapeEndpointDocumentationTests extends MockMvcEndpointDocument
this.mockMvc.perform(get("/actuator/prometheus")).andExpect(status().isOk()).andDo(document("prometheus/all"));
}
@Test
void prometheusOpenmetrics() throws Exception {
this.mockMvc.perform(get("/actuator/prometheus").accept(TextFormat.CONTENT_TYPE_OPENMETRICS_100))
.andExpect(status().isOk())
.andExpect(header().string("Content-Type", "application/openmetrics-text;version=1.0.0;charset=utf-8"))
.andDo(document("prometheus/openmetrics"));
}
@Test
void filteredPrometheus() throws Exception {
this.mockMvc

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@ -0,0 +1,54 @@
/*
* Copyright 2012-2021 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 io.prometheus.client.exporter.common.TextFormat;
import org.springframework.boot.actuate.endpoint.http.Producible;
import org.springframework.util.MimeType;
import org.springframework.util.MimeTypeUtils;
/**
* A {@link Producible} for Prometheus's {@link TextFormat}.
*
* @author Andy Wilkinson
* @since 2.5.0
*/
public enum ProducibleTextFormat implements Producible<ProducibleTextFormat> {
/**
* Openmetrics text version 1.0.0.
*/
CONTENT_TYPE_OPENMETRICS_100(TextFormat.CONTENT_TYPE_OPENMETRICS_100),
/**
* Prometheus text version 0.0.4.
*/
CONTENT_TYPE_004(TextFormat.CONTENT_TYPE_004);
private final MimeType mimeType;
ProducibleTextFormat(String mimeType) {
this.mimeType = MimeTypeUtils.parseMimeType(mimeType);
}
@Override
public MimeType getMimeType() {
return this.mimeType;
}
}

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@ -1,5 +1,5 @@
/*
* Copyright 2012-2020 the original author or authors.
* Copyright 2012-2021 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.
@ -28,8 +28,10 @@ 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.WebEndpointResponse;
import org.springframework.boot.actuate.endpoint.web.annotation.WebEndpoint;
import org.springframework.lang.Nullable;
import org.springframework.util.MimeType;
/**
* {@link Endpoint @Endpoint} that outputs metrics in a format that can be scraped by the
@ -48,15 +50,25 @@ public class PrometheusScrapeEndpoint {
this.collectorRegistry = collectorRegistry;
}
@ReadOperation(produces = TextFormat.CONTENT_TYPE_004)
public String scrape(@Nullable Set<String> includedNames) {
@ReadOperation(produces = { TextFormat.CONTENT_TYPE_004, TextFormat.CONTENT_TYPE_OPENMETRICS_100 })
public WebEndpointResponse<String> scrape(ProducibleTextFormat producibleTextFormat,
@Nullable Set<String> includedNames) {
try {
Writer writer = new StringWriter();
Enumeration<MetricFamilySamples> samples = (includedNames != null)
? this.collectorRegistry.filteredMetricFamilySamples(includedNames)
: this.collectorRegistry.metricFamilySamples();
TextFormat.write004(writer, samples);
return writer.toString();
MimeType contentType = producibleTextFormat.getMimeType();
if (producibleTextFormat == ProducibleTextFormat.CONTENT_TYPE_004) {
TextFormat.write004(writer, samples);
}
else if (producibleTextFormat == ProducibleTextFormat.CONTENT_TYPE_OPENMETRICS_100) {
TextFormat.writeOpenMetrics100(writer, samples);
}
else {
throw new RuntimeException("Unsupported text format '" + producibleTextFormat.getMimeType() + "'");
}
return new WebEndpointResponse<>(writer.toString(), contentType);
}
catch (IOException ex) {
// This actually never happens since StringWriter::write() doesn't throw any

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@ -1,5 +1,5 @@
/*
* Copyright 2012-2020 the original author or authors.
* Copyright 2012-2021 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.
@ -40,13 +40,21 @@ import static org.assertj.core.api.Assertions.assertThat;
class PrometheusScrapeEndpointIntegrationTests {
@WebEndpointTest
void scrapeHasContentTypeText004(WebTestClient client) {
void scrapeHasContentTypeText004ByDefault(WebTestClient client) {
client.get().uri("/actuator/prometheus").exchange().expectStatus().isOk().expectHeader()
.contentType(MediaType.parseMediaType(TextFormat.CONTENT_TYPE_004)).expectBody(String.class)
.value((body) -> assertThat(body).contains("counter1_total").contains("counter2_total")
.contains("counter3_total"));
}
@WebEndpointTest
void scrapeCanProduceOpenMetrics100(WebTestClient client) {
MediaType openMetrics = MediaType.parseMediaType(TextFormat.CONTENT_TYPE_OPENMETRICS_100);
client.get().uri("/actuator/prometheus").accept(openMetrics).exchange().expectStatus().isOk().expectHeader()
.contentType(openMetrics).expectBody(String.class).value((body) -> assertThat(body)
.contains("counter1_total").contains("counter2_total").contains("counter3_total"));
}
@WebEndpointTest
void scrapeWithIncludedNames(WebTestClient client) {
client.get().uri("/actuator/prometheus?includedNames=counter1_total,counter2_total").exchange().expectStatus()