CAMEL-23225: Propagate OpenTelemetry context across thread boundaries in camel-opentelemetry2

[gnodet]

JIRA: CAMEL-23225

Summary

• Port thread pool instrumentation from the deprecated camel-opentelemetry module to camel-opentelemetry2
• Add OpenTelemetryInstrumentedThreadPoolFactory — wraps Camel-managed ExecutorService and ScheduledExecutorService with Context.taskWrapping() to propagate OTel context
• Add OpenTelemetryInstrumentedThreadFactoryListener — wraps ThreadFactory to propagate OTel context via Context.current().wrap()
• Both classes are registered as @JdkService so they are automatically discovered by Camel

This prevents OpenTelemetry context leaks when Camel routes use async processing, thread pools, or other multi-threaded patterns. The deprecated camel-opentelemetry module had these classes, but they were not carried over when camel-opentelemetry2 was created.

Test plan

• All 12 existing camel-opentelemetry2 tests pass
• JDK service files generated correctly for thread-pool-factory and thread-factory-listener
• Verified same pattern as deprecated camel-opentelemetry module

[github-actions]

🌟 Thank you for your contribution to the Apache Camel project! 🌟
🤖 CI automation will test this PR automatically.

🐫 Apache Camel Committers, please review the following items:

• First-time contributors require MANUAL approval for the GitHub Actions to run
• You can use the command /component-test (camel-)component-name1 (camel-)component-name2.. to request a test from the test bot although they are normally detected and executed by CI.
• You can label PRs using build-all, build-dependents, skip-tests and test-dependents to fine-tune the checks executed by this PR.
• Build and test logs are available in the summary page. Only Apache Camel committers have access to the summary.

⚠️ Be careful when sharing logs. Review their contents before sharing them publicly.

[github-actions]

🧪 CI tested the following changed modules:

• components/camel-opentelemetry2
• dsl/camel-kamelet-main

All tested modules (74 modules)

• Camel :: All Components Sync point
• Camel :: All Components Sync point [pom]
• Camel :: Assembly
• Camel :: Assembly [pom]
• Camel :: Catalog :: CSimple Maven Plugin (deprecated) [maven-plugin]
• Camel :: Catalog :: CSimple Maven Plugin (deprecated) SUCCESS [ 1.463 s]
• Camel :: Catalog :: Camel Catalog
• Camel :: Catalog :: Camel Catalog [jar]
• Camel :: Catalog :: Camel Report Maven Plugin
• Camel :: Catalog :: Camel Report Maven Plugin [maven-plugin]
• Camel :: Catalog :: Camel Route Parser
• Camel :: Catalog :: Camel Route Parser [jar]
• Camel :: Catalog :: Console
• Camel :: Catalog :: Console [jar]
• Camel :: Catalog :: Dummy Component
• Camel :: Catalog :: Dummy Component [jar]
• Camel :: Catalog :: Lucene (deprecated)
• Camel :: Catalog :: Lucene (deprecated) [jar]
• Camel :: Catalog :: Maven
• Camel :: Catalog :: Maven [jar]
• Camel :: Catalog :: Suggest
• Camel :: Catalog :: Suggest [jar]
• Camel :: Component DSL
• Camel :: Component DSL [jar]
• Camel :: Coverage
• Camel :: Coverage [pom]
• Camel :: Docs
• Camel :: Docs [pom]
• Camel :: Endpoint DSL
• Camel :: Endpoint DSL [jar]
• Camel :: Endpoint DSL :: Support
• Camel :: Endpoint DSL :: Support [jar]
• Camel :: Integration Tests
• Camel :: Integration Tests [jar]
• Camel :: JBang :: Core
• Camel :: JBang :: Core [jar]
• Camel :: JBang :: Integration tests
• Camel :: JBang :: Integration tests [jar]
• Camel :: JBang :: MCP
• Camel :: JBang :: MCP [jar]
• Camel :: JBang :: Main
• Camel :: JBang :: Main [jar]
• Camel :: JBang :: Plugin :: Edit
• Camel :: JBang :: Plugin :: Edit [jar]
• Camel :: JBang :: Plugin :: Generate
• Camel :: JBang :: Plugin :: Generate [jar]
• Camel :: JBang :: Plugin :: Kubernetes
• Camel :: JBang :: Plugin :: Kubernetes [jar]
• Camel :: JBang :: Plugin :: Route Parser
• Camel :: JBang :: Plugin :: Route Parser [jar]
• Camel :: JBang :: Plugin :: Testing
• Camel :: JBang :: Plugin :: Testing [jar]
• Camel :: JBang :: Plugin :: Validate
• Camel :: JBang :: Plugin :: Validate [jar]
• Camel :: Kamelet Main
• Camel :: Kamelet Main [jar]
• Camel :: Launcher
• Camel :: Launcher [jar]
• Camel :: Launcher :: Container
• Camel :: Launcher :: Container [pom]
• Camel :: Observability Services
• Camel :: Observability Services [jar]
• Camel :: Opentelemetry 2
• Camel :: Opentelemetry 2 [jar]
• Camel :: YAML DSL
• Camel :: YAML DSL [jar]
• Camel :: YAML DSL :: Deserializers
• Camel :: YAML DSL :: Deserializers [jar]
• Camel :: YAML DSL :: Maven Plugins
• Camel :: YAML DSL :: Maven Plugins [maven-plugin]
• Camel :: YAML DSL :: Validator
• Camel :: YAML DSL :: Validator [jar]
• Camel :: YAML DSL :: Validator Maven Plugin
• Camel :: YAML DSL :: Validator Maven Plugin [maven-plugin]

[johnpoth]

This is great and needed thanks @gnodet !

CAMEL-23225 was more about Spring Boot though. This is still needed IMO and should be merged

CAMEL-23225 was about basically the same thing for Spring Boot's default ThreadPoolTaskExecutor which we use in camel-platform-http-starter which doesn't wrap new threads with the otel context like we do here (which causes a context leak). https://docs.spring.io/spring-boot/reference/actuator/observability.html#actuator.observability.context-propagation seems promising by setting spring.reactor.context-propagation to auto (haven't tried it out yet).

If the property doesn't work we could register a new TaskDecorator in the starters

package jp.co.rakutenbank.ifc.routers.fescores.connectivitytest.connectivitydbcore;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.task.TaskDecorator;
import io.opentelemetry.context.Context;

@Configuration(proxyBeanMethods = false)
public class TracingConfig {

    @Bean
    public TaskDecorator otelContextPropagatingDecorator() {
        return runnable -> {
            // Capture the current OTEL context on the submitting thread
            Context currentContext = Context.current();
            // Wrap the runnable so it activates this context on the worker thread
            return () -> {
                try (var ignored = currentContext.makeCurrent()) {
                    runnable.run();
                }
            };
        };
    }
}

Hope this helps!