Add auto-configuration for OtlpMeterRegistry

See gh-30825

spring-boot-project/spring-boot-actuator-autoconfigure/build.gradle

@@ -67,6 +67,7 @@ dependencies {
 	optional("io.micrometer:micrometer-registry-jmx")
 	optional("io.micrometer:micrometer-registry-kairos")
 	optional("io.micrometer:micrometer-registry-new-relic")
+	optional("io.micrometer:micrometer-registry-otlp")
 	optional("io.micrometer:micrometer-registry-prometheus")
 	optional("io.micrometer:micrometer-registry-stackdriver") {
 		exclude group: "commons-logging", module: "commons-logging"

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/export/otlp/OtlpMetricsExportAutoConfiguration.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2012-2022 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.autoconfigure.metrics.export.otlp;
+
+import io.micrometer.core.instrument.Clock;
+import io.micrometer.registry.otlp.OtlpConfig;
+import io.micrometer.registry.otlp.OtlpMeterRegistry;
+
+import org.springframework.boot.actuate.autoconfigure.metrics.CompositeMeterRegistryAutoConfiguration;
+import org.springframework.boot.actuate.autoconfigure.metrics.MetricsAutoConfiguration;
+import org.springframework.boot.actuate.autoconfigure.metrics.export.ConditionalOnEnabledMetricsExport;
+import org.springframework.boot.actuate.autoconfigure.metrics.export.simple.SimpleMetricsExportAutoConfiguration;
+import org.springframework.boot.autoconfigure.AutoConfiguration;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.annotation.Bean;
+
+/**
+ * {@link EnableAutoConfiguration Auto-configuration} for exporting metrics to OTLP.
+ *
+ * @author Eddú Meléndez
+ * @since 3.0.0
+ */
+@AutoConfiguration(
+		before = { CompositeMeterRegistryAutoConfiguration.class, SimpleMetricsExportAutoConfiguration.class },
+		after = MetricsAutoConfiguration.class)
+@ConditionalOnBean(Clock.class)
+@ConditionalOnClass(OtlpMeterRegistry.class)
+@ConditionalOnEnabledMetricsExport("otlp")
+@EnableConfigurationProperties(OtlpProperties.class)
+public class OtlpMetricsExportAutoConfiguration {
+
+	private final OtlpProperties properties;
+
+	public OtlpMetricsExportAutoConfiguration(OtlpProperties properties) {
+		this.properties = properties;
+	}
+
+	@Bean
+	@ConditionalOnMissingBean
+	public OtlpConfig otlpConfig() {
+		return new OtlpPropertiesConfigAdapter(this.properties);
+	}
+
+	@Bean
+	@ConditionalOnMissingBean
+	public OtlpMeterRegistry otlpMeterRegistry(OtlpConfig otlpConfig, Clock clock) {
+		return new OtlpMeterRegistry(otlpConfig, clock);
+	}
+
+}

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/export/otlp/OtlpProperties.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2012-2022 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.autoconfigure.metrics.export.otlp;
+
+import org.springframework.boot.actuate.autoconfigure.metrics.export.properties.StepRegistryProperties;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+/**
+ * {@link ConfigurationProperties @ConfigurationProperties} for configuring OTLP metrics
+ * export.
+ *
+ * @author Eddú Meléndez
+ * @since 3.0.0
+ */
+@ConfigurationProperties(prefix = "management.otlp.metrics.export")
+public class OtlpProperties extends StepRegistryProperties {
+
+	/**
+	 * URI of the OLTP server.
+	 */
+	private String url = "http://localhost:4318/v1/metrics";
+
+	public String getUrl() {
+		return this.url;
+	}
+
+	public void setUrl(String url) {
+		this.url = url;
+	}
+
+}

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/export/otlp/OtlpPropertiesConfigAdapter.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2012-2022 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.autoconfigure.metrics.export.otlp;
+
+import io.micrometer.registry.otlp.OtlpConfig;
+
+import org.springframework.boot.actuate.autoconfigure.metrics.export.properties.StepRegistryPropertiesConfigAdapter;
+
+/**
+ * Adapter to convert {@link OtlpProperties} to an {@link OtlpConfig}.
+ *
+ * @author Eddú Meléndez
+ */
+class OtlpPropertiesConfigAdapter extends StepRegistryPropertiesConfigAdapter<OtlpProperties> implements OtlpConfig {
+
+	OtlpPropertiesConfigAdapter(OtlpProperties properties) {
+		super(properties);
+	}
+
+	@Override
+	public String prefix() {
+		return "management.otlp.metrics.export";
+	}
+
+	@Override
+	public String url() {
+		return get(OtlpProperties::getUrl, OtlpConfig.super::url);
+	}
+
+}

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/export/otlp/package-info.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2012-2022 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.
+ */
+
+/**
+ * Support for exporting actuator metrics to OTLP.
+ */
+package org.springframework.boot.actuate.autoconfigure.metrics.export.otlp;

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/resources/META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports

@@ -59,6 +59,7 @@ org.springframework.boot.actuate.autoconfigure.metrics.export.humio.HumioMetrics
 org.springframework.boot.actuate.autoconfigure.metrics.export.influx.InfluxMetricsExportAutoConfiguration
 org.springframework.boot.actuate.autoconfigure.metrics.export.jmx.JmxMetricsExportAutoConfiguration
 org.springframework.boot.actuate.autoconfigure.metrics.export.kairos.KairosMetricsExportAutoConfiguration
+org.springframework.boot.actuate.autoconfigure.metrics.export.otlp.OtlpMetricsExportAutoConfiguration
 org.springframework.boot.actuate.autoconfigure.metrics.export.newrelic.NewRelicMetricsExportAutoConfiguration
 org.springframework.boot.actuate.autoconfigure.metrics.export.prometheus.PrometheusMetricsExportAutoConfiguration
 org.springframework.boot.actuate.autoconfigure.metrics.export.signalfx.SignalFxMetricsExportAutoConfiguration

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/export/otlp/OtlpMetricsExportAutoConfigurationTests.java

@@ -0,0 +1,112 @@
+/*
+ * Copyright 2012-2022 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.autoconfigure.metrics.export.otlp;
+
+import io.micrometer.core.instrument.Clock;
+import io.micrometer.registry.otlp.OtlpConfig;
+import io.micrometer.registry.otlp.OtlpMeterRegistry;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link OtlpMetricsExportAutoConfiguration}.
+ *
+ * @author Eddú Meléndez
+ */
+class OtlpMetricsExportAutoConfigurationTests {
+
+	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+			.withConfiguration(AutoConfigurations.of(OtlpMetricsExportAutoConfiguration.class));
+
+	@Test
+	void backsOffWithoutAClock() {
+		this.contextRunner.run((context) -> assertThat(context).doesNotHaveBean(OtlpMeterRegistry.class));
+	}
+
+	@Test
+	void autoConfiguresConfigAndMeterRegistry() {
+		this.contextRunner.withUserConfiguration(BaseConfiguration.class).run((context) -> assertThat(context)
+				.hasSingleBean(OtlpMeterRegistry.class).hasSingleBean(OtlpConfig.class));
+	}
+
+	@Test
+	void autoConfigurationCanBeDisabledWithDefaultsEnabledProperty() {
+		this.contextRunner.withUserConfiguration(BaseConfiguration.class)
+				.withPropertyValues("management.defaults.metrics.export.enabled=false")
+				.run((context) -> assertThat(context).doesNotHaveBean(OtlpMeterRegistry.class)
+						.doesNotHaveBean(OtlpConfig.class));
+	}
+
+	@Test
+	void autoConfigurationCanBeDisabledWithSpecificEnabledProperty() {
+		this.contextRunner.withUserConfiguration(BaseConfiguration.class)
+				.withPropertyValues("management.otlp.metrics.export.enabled=false").run((context) -> assertThat(context)
+						.doesNotHaveBean(OtlpMeterRegistry.class).doesNotHaveBean(OtlpConfig.class));
+	}
+
+	@Test
+	void allowsCustomConfigToBeUsed() {
+		this.contextRunner.withUserConfiguration(CustomConfigConfiguration.class).run((context) -> assertThat(context)
+				.hasSingleBean(OtlpMeterRegistry.class).hasSingleBean(OtlpConfig.class).hasBean("customConfig"));
+	}
+
+	@Test
+	void allowsRegistryToBeCustomized() {
+		this.contextRunner.withUserConfiguration(CustomRegistryConfiguration.class).run((context) -> assertThat(context)
+				.hasSingleBean(OtlpMeterRegistry.class).hasSingleBean(OtlpConfig.class).hasBean("customRegistry"));
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class BaseConfiguration {
+
+		@Bean
+		Clock customClock() {
+			return Clock.SYSTEM;
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@Import(BaseConfiguration.class)
+	static class CustomConfigConfiguration {
+
+		@Bean
+		OtlpConfig customConfig() {
+			return (key) -> null;
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@Import(BaseConfiguration.class)
+	static class CustomRegistryConfiguration {
+
+		@Bean
+		OtlpMeterRegistry customRegistry(OtlpConfig config, Clock clock) {
+			return new OtlpMeterRegistry(config, clock);
+		}
+
+	}
+
+}

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/export/otlp/OtlpPropertiesTests.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2012-2022 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.autoconfigure.metrics.export.otlp;
+
+import io.micrometer.registry.otlp.OtlpConfig;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.actuate.autoconfigure.metrics.export.properties.StepRegistryPropertiesTests;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link OtlpProperties}.
+ *
+ * @author Eddú Meléndez
+ */
+class OtlpPropertiesTests extends StepRegistryPropertiesTests {
+
+	@Test
+	void defaultValuesAreConsistent() {
+		OtlpProperties properties = new OtlpProperties();
+		OtlpConfig config = OtlpConfig.DEFAULT;
+		assertStepRegistryDefaultValues(properties, config);
+		assertThat(properties.getUrl()).isEqualTo(config.url());
+	}
+
+}

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/test/MetricsRun.java

@@ -30,6 +30,7 @@ import org.springframework.boot.actuate.autoconfigure.metrics.export.graphite.Gr
 import org.springframework.boot.actuate.autoconfigure.metrics.export.influx.InfluxMetricsExportAutoConfiguration;
 import org.springframework.boot.actuate.autoconfigure.metrics.export.jmx.JmxMetricsExportAutoConfiguration;
 import org.springframework.boot.actuate.autoconfigure.metrics.export.newrelic.NewRelicMetricsExportAutoConfiguration;
+import org.springframework.boot.actuate.autoconfigure.metrics.export.otlp.OtlpMetricsExportAutoConfiguration;
 import org.springframework.boot.actuate.autoconfigure.metrics.export.prometheus.PrometheusMetricsExportAutoConfiguration;
 import org.springframework.boot.actuate.autoconfigure.metrics.export.signalfx.SignalFxMetricsExportAutoConfiguration;
 import org.springframework.boot.actuate.autoconfigure.metrics.export.simple.SimpleMetricsExportAutoConfiguration;
@@ -59,6 +60,7 @@ public final class MetricsRun {
 		implementations.add(InfluxMetricsExportAutoConfiguration.class);
 		implementations.add(JmxMetricsExportAutoConfiguration.class);
 		implementations.add(NewRelicMetricsExportAutoConfiguration.class);
+		implementations.add(OtlpMetricsExportAutoConfiguration.class);
 		implementations.add(PrometheusMetricsExportAutoConfiguration.class);
 		implementations.add(SimpleMetricsExportAutoConfiguration.class);
 		implementations.add(SignalFxMetricsExportAutoConfiguration.class);

spring-boot-project/spring-boot-docs/src/docs/asciidoc/actuator/metrics.adoc

@@ -14,6 +14,7 @@ Spring Boot Actuator provides dependency management and auto-configuration for h
 - <<actuator#actuator.metrics.export.jmx,JMX>>
 - <<actuator#actuator.metrics.export.kairos,KairosDB>>
 - <<actuator#actuator.metrics.export.newrelic,New Relic>>
+- <<actuator#actuator.metrics.export.otlp,OpenTelemetry>>
 - <<actuator#actuator.metrics.export.prometheus,Prometheus>>
 - <<actuator#actuator.metrics.export.signalfx,SignalFx>>
 - <<actuator#actuator.metrics.export.simple,Simple (in-memory)>>
@@ -437,6 +438,22 @@ Finally, you can take full control by defining your own `NewRelicClientProvider`
 
 
 
+[[actuator.metrics.export.otlp]]
+==== OpenTelemetry
+By default, metrics are exported to {micrometer-registry-docs}/otlp[OpenTelemetry] running on your local machine.
+You can provide the location of the https://opentelemetry.io/[OpenTelemtry metric endpoint] to use by using:
+
+[source,yaml,indent=0,subs="verbatim",configprops,configblocks]
+----
+	management:
+	  otlp:
+	    metrics:
+	      export:
+	        url: "https://otlp.example.com:4318/v1/metrics"
+----
+
+
+
 [[actuator.metrics.export.prometheus]]
 ==== Prometheus
 {micrometer-registry-docs}/prometheus[Prometheus] expects to scrape or poll individual application instances for metrics.