OSGi support and tests for OTLP exporters

buildSrc/src/main/kotlin/io/opentelemetry/gradle/OtelJavaExtension.kt

@@ -23,12 +23,31 @@ abstract class OtelJavaExtension {
     // with resolution:=optional but no version constraint.
     abstract val osgiUnversionedOptionalPackages: ListProperty<String>
 
+    // SPI interfaces whose implementations this bundle registers via META-INF/services.
+    // Generates Provide-Capability: osgi.serviceloader;... and requires the registrar extender.
+    abstract val osgiServiceLoaderProvides: ListProperty<String>
+
+    // SPI interfaces this bundle discovers at runtime via ServiceLoader.
+    // Generates Require-Capability: osgi.serviceloader;... (resolution:=optional) to hint the
+    // BND resolver to include provider bundles. Does NOT add the processor extender requirement —
+    // use osgiServiceLoaderProcessor for that.
+    abstract val osgiServiceLoaderRequires: ListProperty<String>
+
+    // When true, adds Require-Capability: osgi.extender=osgi.serviceloader.processor so that a
+    // ServiceLoader mediator (e.g. SPI Fly) weaves this bundle's ServiceLoader.load() calls to
+    // route through the OSGi service registry. Set this on whichever bundle contains the actual
+    // ServiceLoader.load() call site; the SPI types being loaded live elsewhere.
+    abstract val osgiServiceLoaderProcessor: Property<Boolean>
+
     abstract val minJavaVersionSupported: Property<JavaVersion>
 
     init {
         minJavaVersionSupported.convention(JavaVersion.VERSION_1_8)
         osgiEnabled.convention(true)
-        osgiOptionalPackages.convention(emptyList<String>())
-        osgiUnversionedOptionalPackages.convention(emptyList<String>())
+        osgiOptionalPackages.convention(emptyList())
+        osgiUnversionedOptionalPackages.convention(emptyList())
+        osgiServiceLoaderProvides.convention(emptyList())
+        osgiServiceLoaderRequires.convention(emptyList())
+        osgiServiceLoaderProcessor.convention(false)
     }
 }

buildSrc/src/main/kotlin/otel.japicmp-conventions.gradle.kts

@@ -168,7 +168,7 @@ if (!project.hasProperty("otel.release") && !project.name.startsWith("bom")) {
         packageExcludes.addAll(
           "*.internal",
           "*.internal.*",
-          "io.opentelemetry.internal.shaded.jctools.*",
+          "io.opentelemetry.sdk.trace.internal.shaded.jctools.*",
           // Temporarily suppress warnings from public generated classes from :sdk-extensions:jaeger-remote-sampler
           "io.opentelemetry.sdk.extension.trace.jaeger.proto.api_v2"
         )

buildSrc/src/main/kotlin/otel.java-conventions.gradle.kts

@@ -154,12 +154,43 @@ tasks {
           val unversionedImports = unversionedOptionalPackages.joinToString(",") { "$it.*;resolution:=optional" }
           val fullImportPackages = if (unversionedImports.isNotEmpty()) "$unversionedImports,$importPackages" else importPackages
 
-          bnd(mapOf(
-            // Exclude shaded internal packages from exports; they are implementation details and
-            // should not be part of the OSGi bundle's public API surface.
-            "-exportcontents" to "!io.opentelemetry.internal.shaded.*,io.opentelemetry.*",
+          val bndInstructions = mutableMapOf(
+            "-exportcontents" to "io.opentelemetry.*",
             "Import-Package" to fullImportPackages
-          ))
+          )
+
+          // OSGi ServiceLoader Mediator capabilities.
+          // Providers declare what SPI implementations they register via META-INF/services.
+          // Consumers declare what SPI interfaces they discover at runtime via ServiceLoader.
+          // Both require the corresponding extender from a ServiceLoader mediator (e.g. SPI Fly).
+          val slProvides = otelJava.osgiServiceLoaderProvides.get()
+          val slRequires = otelJava.osgiServiceLoaderRequires.get()
+          val requireClauses = mutableListOf<String>()
+
+          if (slProvides.isNotEmpty()) {
+            bndInstructions["Provide-Capability"] = slProvides.joinToString(",") {
+              "osgi.serviceloader;osgi.serviceloader=\"$it\""
+            }
+            requireClauses.add("osgi.extender;filter:=\"(osgi.extender=osgi.serviceloader.registrar)\"")
+          }
+          if (slRequires.isNotEmpty()) {
+            slRequires.forEach {
+              // resolution:=optional: hints the BND resolver to include provider bundles.
+              // Does not add the processor extender — use osgiServiceLoaderProcessor for that.
+              requireClauses.add("osgi.serviceloader;filter:=\"(osgi.serviceloader=$it)\";cardinality:=multiple;resolution:=optional")
+            }
+          }
+          if (otelJava.osgiServiceLoaderProcessor.get()) {
+            // Mandatory: actively pulls a ServiceLoader processor (e.g. SPI Fly) into the resolved
+            // bundle set so that ServiceLoader.load() calls are routed via the OSGi service registry.
+            // Set on whichever bundle contains the ServiceLoader.load() call site.
+            requireClauses.add("osgi.extender;filter:=\"(osgi.extender=osgi.serviceloader.processor)\"")
+          }
+          if (requireClauses.isNotEmpty()) {
+            bndInstructions["Require-Capability"] = requireClauses.joinToString(",")
+          }
+
+          bnd(bndInstructions)
         }
       }
     }

common/build.gradle.kts

@@ -7,6 +7,9 @@ plugins {
 
 description = "OpenTelemetry API Common"
 otelJava.moduleName.set("io.opentelemetry.common")
+// ServiceLoaderComponentLoader (this bundle) is the ServiceLoader.load() call site for all
+// ComponentLoader.forClassLoader() usage; requires the processor extender to weave it.
+otelJava.osgiServiceLoaderProcessor.set(true)
 
 dependencies {
 }

dependencyManagement/build.gradle.kts

@@ -89,6 +89,7 @@ val DEPENDENCIES = listOf(
   "io.opentracing:opentracing-noop:0.33.0",
   "junit:junit:4.13.2",
   "nl.jqno.equalsverifier:equalsverifier:3.19.4",
+  "org.apache.aries.spifly:org.apache.aries.spifly.dynamic.bundle:1.3.7",
   "org.apache.felix:org.apache.felix.framework:7.0.5",
   "org.awaitility:awaitility:4.3.0",
   "org.codehaus.mojo:animal-sniffer-annotations:1.27",

exporters/common/build.gradle.kts

@@ -7,6 +7,14 @@ plugins {
 
 description = "OpenTelemetry Exporter Common"
 otelJava.moduleName.set("io.opentelemetry.exporter.internal")
+otelJava.osgiOptionalPackages.set(listOf("com.fasterxml.jackson.core", "com.google.common.io", "io.opentelemetry.api.incubator.config"))
+// sun.misc, io.grpc, and org.jspecify are not OSGi bundles and have no package versioning; must use unversioned optional.
+otelJava.osgiUnversionedOptionalPackages.set(listOf("sun.misc", "io.grpc", "org.jspecify.annotations"))
+// This bundle's exporters load sender implementations via SPI.
+otelJava.osgiServiceLoaderRequires.set(listOf(
+  "io.opentelemetry.sdk.common.export.GrpcSenderProvider",
+  "io.opentelemetry.sdk.common.export.HttpSenderProvider"
+))
 
 java {
   sourceSets {

exporters/otlp/all/build.gradle.kts

@@ -9,6 +9,9 @@ apply<io.opentelemetry.gradle.OtelVersionClassPlugin>()
 
 description = "OpenTelemetry Protocol (OTLP) Exporters"
 otelJava.moduleName.set("io.opentelemetry.exporter.otlp")
+otelJava.osgiOptionalPackages.set(listOf("io.opentelemetry.api.incubator.config"))
+// io.grpc is not an OSGi bundle and has no package versioning; must use unversioned optional.
+otelJava.osgiUnversionedOptionalPackages.set(listOf("io.grpc"))
 base.archivesName.set("opentelemetry-exporter-otlp")
 
 dependencies {

exporters/otlp/common/build.gradle.kts

@@ -10,6 +10,7 @@ plugins {
 
 description = "OpenTelemetry Protocol Exporter"
 otelJava.moduleName.set("io.opentelemetry.exporter.internal.otlp")
+otelJava.osgiOptionalPackages.set(listOf("io.opentelemetry.api.incubator"))
 
 val versions: Map<String, String> by project
 dependencies {

exporters/sender/jdk/build.gradle.kts

@@ -8,6 +8,7 @@ plugins {
 description = "OpenTelemetry JDK HttpSender"
 otelJava.moduleName.set("io.opentelemetry.exporter.sender.jdk.internal")
 otelJava.minJavaVersionSupported.set(JavaVersion.VERSION_11)
+otelJava.osgiServiceLoaderProvides.set(listOf("io.opentelemetry.sdk.common.export.HttpSenderProvider"))
 
 dependencies {
   annotationProcessor("com.google.auto.value:auto-value")

exporters/sender/okhttp/build.gradle.kts

@@ -7,6 +7,13 @@ plugins {
 
 description = "OpenTelemetry OkHttp Senders"
 otelJava.moduleName.set("io.opentelemetry.exporter.sender.okhttp.internal")
+otelJava.osgiServiceLoaderProvides.set(listOf(
+  "io.opentelemetry.sdk.common.export.GrpcSenderProvider",
+  "io.opentelemetry.sdk.common.export.HttpSenderProvider"
+))
+// okhttp3, okio, and org.jspecify.annotations are not OSGi bundles; imports must be optional.
+// (org.jspecify.annotations is pulled in by OkHttp's Kotlin-compiled types, not this bundle's code.)
+otelJava.osgiUnversionedOptionalPackages.set(listOf("okhttp3", "okio", "org.jspecify.annotations"))
 
 dependencies {
   implementation(project(":exporters:common"))