io.micrometer.tracing.otel.bridge.OtelCurrentTraceContext Maven / Gradle / Ivy
/**
* Copyright 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 io.micrometer.tracing.otel.bridge;
import java.util.concurrent.Callable;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import io.micrometer.tracing.CurrentTraceContext;
import io.micrometer.tracing.TraceContext;
import io.opentelemetry.api.baggage.Baggage;
import io.opentelemetry.api.baggage.BaggageBuilder;
import io.opentelemetry.api.trace.Span;
import io.opentelemetry.api.trace.SpanContext;
import io.opentelemetry.context.Context;
import io.opentelemetry.context.ContextKey;
/**
* OpenTelemetry implementation of a {@link CurrentTraceContext}.
*
* @author Marcin Grzejszczak
* @author John Watson
* @since 1.0.0
*/
public class OtelCurrentTraceContext implements CurrentTraceContext {
private static final String TRACING_OTEL_CONTEXT_KEY = "otelTraceContext";
private static final ContextKey OTEL_CONTEXT_KEY = ContextKey.named(TRACING_OTEL_CONTEXT_KEY);
@Override
public TraceContext context() {
OtelTraceContext otelTraceContext = Context.current().get(OTEL_CONTEXT_KEY);
if (otelTraceContext != null) {
return otelTraceContext;
}
Span currentSpan = Span.current();
if (Span.getInvalid().equals(currentSpan)) {
return null;
}
if (currentSpan instanceof SpanFromSpanContext) {
return ((SpanFromSpanContext) currentSpan).parentTraceContext;
}
return new OtelTraceContext(currentSpan);
}
/**
* Since OpenTelemetry works on statics, and we would like to pass the tracing
* information on the {@link TraceContext} we are checking what we have currently in
* ThreadLocal and what was passed on {@link TraceContext}.
* @param context span to place into scope or {@code null} to clear the scope
* @return scope that always must be closed
*/
@Override
public Scope newScope(TraceContext context) {
OtelTraceContext otelTraceContext = (OtelTraceContext) context;
if (otelTraceContext == null) {
return new WrappedScope(io.opentelemetry.context.Scope.noop());
}
Context current = Context.current();
Context oldContext = otelTraceContext.context();
// Check if there's a span in the static OTel context
Span spanFromCurrentCtx = Span.fromContext(current);
// Check if there's a span in the ctx attached to TraceContext
Span spanFromCtxOnNewSpan = Span.fromContext(otelTraceContext.context());
SpanContext spanContext = otelTraceContext.delegate;
boolean sameSpan = spanFromCurrentCtx.getSpanContext().equals(spanFromCtxOnNewSpan.getSpanContext())
&& spanFromCurrentCtx.getSpanContext().equals(spanContext);
SpanFromSpanContext fromContext = new SpanFromSpanContext(((OtelTraceContext) context).span, spanContext,
otelTraceContext);
Baggage currentBaggage = Baggage.fromContext(current);
Baggage oldBaggage = Baggage.fromContext(oldContext);
boolean sameBaggage = sameBaggage(currentBaggage, oldBaggage);
if (sameSpan && sameBaggage) {
return new WrappedScope(io.opentelemetry.context.Scope.noop());
}
Baggage updatedBaggage = mergeBaggage(currentBaggage, oldBaggage);
Context newContext = oldContext.with(fromContext).with(updatedBaggage).with(OTEL_CONTEXT_KEY, otelTraceContext);
io.opentelemetry.context.Scope newScope = newContext.makeCurrent();
otelTraceContext.updateContext(newContext);
return new WrappedScope(newScope, otelTraceContext, oldContext);
}
private static Baggage mergeBaggage(Baggage currentBaggage, Baggage oldBaggage) {
BaggageBuilder baggageBuilder = currentBaggage.toBuilder();
oldBaggage.forEach(
(key, baggageEntry) -> baggageBuilder.put(key, baggageEntry.getValue(), baggageEntry.getMetadata()));
return baggageBuilder.build();
}
private boolean sameBaggage(Baggage currentBaggage, Baggage oldBaggage) {
return currentBaggage.equals(oldBaggage);
}
@Override
public Scope maybeScope(TraceContext context) {
if (context == null) {
io.opentelemetry.context.Scope scope = Context.root().makeCurrent();
return new WrappedScope(scope);
}
return newScope(context);
}
@Override
public Callable wrap(Callable task) {
return Context.current().wrap(task);
}
@Override
public Runnable wrap(Runnable task) {
return Context.current().wrap(task);
}
@Override
public Executor wrap(Executor delegate) {
return Context.current().wrap(delegate);
}
@Override
public ExecutorService wrap(ExecutorService delegate) {
return Context.current().wrap(delegate);
}
static class WrappedScope implements Scope {
final io.opentelemetry.context.Scope scope;
final OtelTraceContext currentOtelTraceContext;
final Context oldContext;
WrappedScope(io.opentelemetry.context.Scope scope) {
this(scope, null, null);
}
WrappedScope(io.opentelemetry.context.Scope scope, OtelTraceContext currentOtelTraceContext,
Context oldContext) {
this.scope = scope;
this.currentOtelTraceContext = currentOtelTraceContext;
this.oldContext = oldContext;
}
@Override
public void close() {
if (this.currentOtelTraceContext != null) {
currentOtelTraceContext.updateContext(oldContext);
}
this.scope.close();
}
}
}