Connect the dd-openfeature SDK to the agent

.github/workflows/run-system-tests.yaml

@@ -49,14 +49,18 @@ jobs:
           JAVA_11_HOME=$JAVA_HOME_11_X64 \
           JAVA_17_HOME=$JAVA_HOME_17_X64 \
           JAVA_21_HOME=$JAVA_HOME_21_X64 \
-          ./gradlew clean :dd-java-agent:shadowJar \
+          ./gradlew clean :dd-java-agent:shadowJar :dd-openfeature:jar \
             --build-cache --parallel --stacktrace --no-daemon --max-workers=4
+          mkdir -p workspace/system-tests-binaries
+          cp workspace/dd-java-agent/build/libs/dd-java-agent-*.jar \
+            workspace/dd-openfeature/build/libs/dd-openfeature-*.jar \
+            workspace/system-tests-binaries/
 
       - name: Upload artifact
         uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a
         with:
           name: binaries
-          path: workspace/dd-java-agent/build/libs/
+          path: workspace/system-tests-binaries/
 
   main:
     needs:

.gitlab-ci.yml

@@ -354,7 +354,7 @@ build:
   script:
     - if [ $CI_PIPELINE_SOURCE == "schedule" ] ; then ./gradlew resolveAndLockAll --write-locks $GRADLE_ARGS; fi
     - ./gradlew --version
-    - ./gradlew clean :dd-java-agent:shadowJar :dd-java-agent:check :dd-trace-api:jar :dd-trace-ot:shadowJar :products:feature-flagging:feature-flagging-api:jar -PskipTests -x spotlessCheck $GRADLE_ARGS
+    - ./gradlew clean :dd-java-agent:shadowJar :dd-java-agent:check :dd-trace-api:jar :dd-trace-ot:shadowJar :dd-openfeature:jar -PskipTests -x spotlessCheck $GRADLE_ARGS
     - echo UPSTREAM_TRACER_VERSION=$(java -jar workspace/dd-java-agent/build/libs/*.jar) >> upstream.env
     - echo "BUILD_JOB_NAME=$CI_JOB_NAME" >> build.env
     - echo "BUILD_JOB_ID=$CI_JOB_ID" >> build.env
@@ -364,7 +364,7 @@ build:
       - 'workspace/dd-java-agent/build/libs/*.jar'
       - 'workspace/dd-trace-api/build/libs/*.jar'
       - 'workspace/dd-trace-ot/build/libs/*.jar'
-      - 'workspace/products/feature-flagging/feature-flagging-api/build/libs/*.jar'
+      - 'workspace/dd-openfeature/build/libs/*.jar'
       - 'upstream.env'
       - '.gradle/daemon/*/*.out.log'
     reports:
@@ -481,11 +481,11 @@ publish-artifacts-to-s3:
     - aws s3 cp workspace/dd-java-agent/build/libs/dd-java-agent-${VERSION}.jar s3://dd-trace-java-builds/${CI_COMMIT_REF_NAME}/dd-java-agent.jar
     - aws s3 cp workspace/dd-trace-api/build/libs/dd-trace-api-${VERSION}.jar s3://dd-trace-java-builds/${CI_COMMIT_REF_NAME}/dd-trace-api.jar
     - aws s3 cp workspace/dd-trace-ot/build/libs/dd-trace-ot-${VERSION}.jar s3://dd-trace-java-builds/${CI_COMMIT_REF_NAME}/dd-trace-ot.jar
-    - aws s3 cp workspace/products/feature-flagging/feature-flagging-api/build/libs/dd-openfeature-${VERSION}.jar s3://dd-trace-java-builds/${CI_COMMIT_REF_NAME}/dd-openfeature.jar
+    - aws s3 cp workspace/dd-openfeature/build/libs/dd-openfeature-${VERSION}.jar s3://dd-trace-java-builds/${CI_COMMIT_REF_NAME}/dd-openfeature.jar
     - aws s3 cp workspace/dd-java-agent/build/libs/dd-java-agent-${VERSION}.jar s3://dd-trace-java-builds/${CI_PIPELINE_ID}/dd-java-agent.jar
     - aws s3 cp workspace/dd-trace-api/build/libs/dd-trace-api-${VERSION}.jar s3://dd-trace-java-builds/${CI_PIPELINE_ID}/dd-trace-api.jar
     - aws s3 cp workspace/dd-trace-ot/build/libs/dd-trace-ot-${VERSION}.jar s3://dd-trace-java-builds/${CI_PIPELINE_ID}/dd-trace-ot.jar
-    - aws s3 cp workspace/products/feature-flagging/feature-flagging-api/build/libs/dd-openfeature-${VERSION}.jar s3://dd-trace-java-builds/${CI_PIPELINE_ID}/dd-openfeature.jar
+    - aws s3 cp workspace/dd-openfeature/build/libs/dd-openfeature-${VERSION}.jar s3://dd-trace-java-builds/${CI_PIPELINE_ID}/dd-openfeature.jar
     - |
       cat << EOF > links.json 
         {
@@ -583,6 +583,7 @@ validate_build:
     - cp workspace/dd-java-agent/build/libs/*.jar reference-artifacts/
     - cp workspace/dd-trace-api/build/libs/*.jar reference-artifacts/
     - cp workspace/dd-trace-ot/build/libs/*.jar reference-artifacts/
+    - cp workspace/dd-openfeature/build/libs/*.jar reference-artifacts/
     # Scheduled builds refresh dependency locks before creating the reference artifacts.
     # Refresh them here as well so the candidate uses the same dependency resolution.
     - if [ $CI_PIPELINE_SOURCE == "schedule" ] ; then ./gradlew resolveAndLockAll --write-locks $GRADLE_ARGS; fi
@@ -596,6 +597,7 @@ validate_build:
         cp workspace/dd-java-agent/build/libs/*.jar check_reports/jar-comparison-artifacts/candidate/
         cp workspace/dd-trace-api/build/libs/*.jar check_reports/jar-comparison-artifacts/candidate/
         cp workspace/dd-trace-ot/build/libs/*.jar check_reports/jar-comparison-artifacts/candidate/
+        cp workspace/dd-openfeature/build/libs/*.jar check_reports/jar-comparison-artifacts/candidate/
         exit 1
       fi
   after_script:

dd-openfeature/build.gradle.kts

@@ -4,24 +4,29 @@ import me.champeau.gradle.japicmp.JapicmpTask
 
 plugins {
   `java-library`
-  idea
-  id("dd-trace-java.conventions.java")
+  id("dd-trace-java.module.distributable.api")
   id("dd-trace-java.version-file")
   id("dd-trace-java.jmh-conventions")
 }
 
 description = "Datadog OpenFeature provider SDK."
 
-configure<TestJvmConstraintsExtension> {
-  minJavaVersion.set(JavaVersion.VERSION_11)
+// Set both JAR and Maven artifact name
+val openFeatureArtifactId = "dd-openfeature"
+base {
+  archivesName.set(openFeatureArtifactId)
 }
 
-idea {
-  module {
-    jdkName = "11"
+publishing {
+  publications.withType<MavenPublication>().configureEach {
+    artifactId = openFeatureArtifactId
   }
 }
 
+configure<TestJvmConstraintsExtension> {
+  minJavaVersion.set(JavaVersion.VERSION_11)
+}
+
 java {
   toolchain {
     languageVersion = JavaLanguageVersion.of(11)
@@ -45,6 +50,16 @@ tasks.withType<JavaCompile>().configureEach {
   configureCompiler(JavaVersion.VERSION_11)
 }
 
+tasks.withType<Javadoc>().configureEach {
+  javadocTool = javaToolchains.javadocToolFor(java.toolchain)
+}
+
+tasks.named<Jar>("jar") {
+  manifest {
+    attributes("Automatic-Module-Name" to "com.datadog.openfeature")
+  }
+}
+
 // The agent bridge SPI versions, with the first SDK release shipping each of them. A released
 // version is frozen (only default methods can be added): check it against that release.
 // TODO Set the v1 baseline once the first SDK release with the agent bridge is published.
@@ -71,3 +86,25 @@ bridgeSpiBaselines.forEach { (spi, baseline) ->
     }
   }
 }
+
+// The public API, outside the internal packages, must stay compatible with the previous release:
+// each release keeps the API of all the previous ones. The previous release is the latest one
+// before the version being built, so release branches compare against their own line.
+val publicApiBaseline = "(,${version.toString().removeSuffix("-SNAPSHOT")})"
+val japicmpPublicApi = tasks.register<JapicmpTask>("japicmpPublicApi") {
+  description = "Checks the public API stays compatible with the previous dd-openfeature release."
+  val baselineSdk = "com.datadoghq:dd-openfeature:$publicApiBaseline"
+  oldArchives.from(configurations.detachedConfiguration(dependencies.create("$baselineSdk@jar")))
+  oldClasspath.from(configurations.detachedConfiguration(dependencies.create(baselineSdk)))
+  newArchives.from(tasks.named<Jar>("jar"))
+  newClasspath.from(configurations.named("runtimeClasspath"))
+  packageIncludes.addAll("com.datadog.openfeature", "datadog.trace.api.openfeature")
+  failOnModification.set(true)
+  failOnSourceIncompatibility.set(true)
+  // TODO Remove once the baseline is 1.69.0 or later: earlier releases link the agent bootstrap API.
+  ignoreMissingClasses.set(true)
+  txtOutputFile.set(layout.buildDirectory.file("reports/japicmp/public-api.txt"))
+}
+tasks.named("check") {
+  dependsOn(japicmpPublicApi)
+}

dd-openfeature/gradle.lockfile

@@ -34,7 +34,7 @@ org.apache.commons:commons-math3:3.6.1=jmh,jmhCompileClasspath,jmhRuntimeClasspa
 org.apache.commons:commons-text:1.15.0=spotbugs
 org.apache.logging.log4j:log4j-api:2.26.1=spotbugs
 org.apache.logging.log4j:log4j-core:2.26.1=spotbugs
-org.apiguardian:apiguardian-api:1.1.2=testCompileClasspath
+org.apiguardian:apiguardian-api:1.1.2=jmhRuntimeClasspath,testCompileClasspath,testRuntimeClasspath
 org.codehaus.groovy:groovy-ant:3.0.23=codenarc
 org.codehaus.groovy:groovy-docgenerator:3.0.23=codenarc
 org.codehaus.groovy:groovy-groovydoc:3.0.23=codenarc

dd-openfeature/src/main/java/com/datadog/openfeature/internal/FeatureFlagsRuntime.java

@@ -17,6 +17,7 @@
 import com.datadog.openfeature.internal.flagevaluation.FlagEvaluationPipeline;
 import com.datadog.openfeature.internal.ufc.ServerConfiguration;
 import java.util.HashMap;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.CopyOnWriteArrayList;
@@ -258,8 +259,13 @@ void stop() {
   }
 
   private void onConfiguration(@Nullable final ServerConfiguration configuration) {
-    this.configuration = configuration;
-    for (final Consumer<ServerConfiguration> listener : this.listeners) {
+    final Iterator<Consumer<ServerConfiguration>> snapshot;
+    synchronized (this.listeners) {
+      this.configuration = configuration;
+      snapshot = this.listeners.iterator();
+    }
+    while (snapshot.hasNext()) {
+      final Consumer<ServerConfiguration> listener = snapshot.next();
       try {
         listener.accept(configuration);
       } catch (final RuntimeException e) {
@@ -274,10 +280,13 @@ private void onConfiguration(@Nullable final ServerConfiguration configuration)
    * @param listener the listener to add.
    */
   public void addConfigurationListener(final Consumer<ServerConfiguration> listener) {
-    this.listeners.add(listener);
-    final ServerConfiguration current = this.configuration;
-    if (current != null) {
-      listener.accept(current);
+    // Keep registration and replay atomic with notification snapshots.
+    synchronized (this.listeners) {
+      this.listeners.add(listener);
+      final ServerConfiguration current = this.configuration;
+      if (current != null) {
+        listener.accept(current);
+      }
     }
   }