org.springframework.boot.actuate.autoconfigure.tracing.prometheus.PrometheusExemplarsAutoConfiguration Maven / Gradle / Ivy
/*
* Copyright 2012-2024 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.tracing.prometheus;
import io.micrometer.tracing.Span;
import io.micrometer.tracing.Tracer;
import io.prometheus.metrics.tracer.common.SpanContext;
import org.springframework.beans.factory.ObjectProvider;
import org.springframework.boot.actuate.autoconfigure.metrics.export.prometheus.PrometheusMetricsExportAutoConfiguration;
import org.springframework.boot.actuate.autoconfigure.tracing.MicrometerTracingAutoConfiguration;
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.context.annotation.Bean;
import org.springframework.util.function.SingletonSupplier;
/**
* {@link EnableAutoConfiguration Auto-configuration} for Prometheus Exemplars with
* Micrometer Tracing.
*
* @author Jonatan Ivanov
* @since 3.0.0
*/
@AutoConfiguration(before = PrometheusMetricsExportAutoConfiguration.class,
after = MicrometerTracingAutoConfiguration.class)
@ConditionalOnBean(Tracer.class)
@ConditionalOnClass({ Tracer.class, SpanContext.class })
public class PrometheusExemplarsAutoConfiguration {
@Bean
@ConditionalOnMissingBean
SpanContext spanContext(ObjectProvider tracerProvider) {
return new LazyTracingSpanContext(tracerProvider);
}
/**
* Since the MeterRegistry can depend on the {@link Tracer} (Exemplars) and the
* {@link Tracer} can depend on the MeterRegistry (recording metrics), this
* {@link SpanContext} breaks the cycle by lazily loading the {@link Tracer}.
*/
static class LazyTracingSpanContext implements SpanContext {
private final SingletonSupplier tracer;
LazyTracingSpanContext(ObjectProvider tracerProvider) {
this.tracer = SingletonSupplier.of(tracerProvider::getObject);
}
@Override
public String getCurrentTraceId() {
Span currentSpan = currentSpan();
return (currentSpan != null) ? currentSpan.context().traceId() : null;
}
@Override
public String getCurrentSpanId() {
Span currentSpan = currentSpan();
return (currentSpan != null) ? currentSpan.context().spanId() : null;
}
@Override
public boolean isCurrentSpanSampled() {
Span currentSpan = currentSpan();
if (currentSpan == null) {
return false;
}
Boolean sampled = currentSpan.context().sampled();
return sampled != null && sampled;
}
@Override
public void markCurrentSpanAsExemplar() {
}
private Span currentSpan() {
return this.tracer.obtain().currentSpan();
}
}
}