Add PropagationContextElement Kotlin operator

Prior to this commit, the Micrometer context-propagation project would
help propagating information from `ThreadLocal`, Reactor `Context` and
other context objects. This is already well supported for Micrometer
Observations.

In the case of Kotlin suspending functions, the processing of tasks
would not necessarily update the `ThreadLocal` when the function is
scheduled on a different thread.

This commit introduces the `PropagationContextElement` operator that
connects the `ThreadLocal`, Reactor `Context` and Coroutine `Context`
for all libraries using the "context-propagation" project.

Applications must manually use this operator in suspending functions
like so:

```
suspend fun suspendingFunction() {
  return withContext(PropagationContextElement(currentCoroutineContext())) {
    logger.info("Suspending function with traceId")
  }
}
```

Closes gh-35185
This commit is contained in:
Brian Clozel
2025-09-09 21:42:08 +02:00
parent 21e52a4283
commit ef2a403df6
6 changed files with 246 additions and 0 deletions
+3
View File
@@ -65,6 +65,7 @@ dependencies {
implementation("com.github.ben-manes.caffeine:caffeine")
implementation("com.mchange:c3p0:0.9.5.5")
implementation("com.oracle.database.jdbc:ojdbc11")
implementation("io.micrometer:context-propagation")
implementation("io.projectreactor.netty:reactor-netty-http")
implementation("jakarta.jms:jakarta.jms-api")
implementation("jakarta.servlet:jakarta.servlet-api")
@@ -78,6 +79,8 @@ dependencies {
implementation("org.assertj:assertj-core")
implementation("org.eclipse.jetty.websocket:jetty-websocket-jetty-api")
implementation("org.jetbrains.kotlin:kotlin-stdlib")
implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core")
implementation("org.jetbrains.kotlinx:kotlinx-coroutines-reactor")
implementation("org.junit.jupiter:junit-jupiter-api")
implementation("tools.jackson.core:jackson-databind")
implementation("tools.jackson.dataformat:jackson-dataformat-xml")