Add context propagation to the Zipkin tracing provider (helidon-io#9119)

* Add context propagation to the Zipkin tracing provider

Signed-off-by: Tim Quinn <[email protected]>

Author: tjquinno

tracing/providers/opentelemetry/src/main/java/io/helidon/tracing/providers/opentelemetry/OpenTelemetryDataPropagationProvider.java

@@ -62,7 +62,7 @@ public void propagateData(OpenTelemetryContext context) {
     }
 
     /**
-     * OpenTelementry context.
+     * OpenTelemetry context.
      */
     public static class OpenTelemetryContext {
         private final Span span;

tracing/providers/opentracing/src/main/java/io/helidon/tracing/providers/opentracing/OpenTracingTracerProvider.java

@@ -23,6 +23,8 @@
 import io.helidon.common.LazyValue;
 import io.helidon.common.Weight;
 import io.helidon.common.Weighted;
+import io.helidon.common.config.Config;
+import io.helidon.common.config.GlobalConfig;
 import io.helidon.tracing.Span;
 import io.helidon.tracing.SpanListener;
 import io.helidon.tracing.Tracer;
@@ -35,27 +37,48 @@
 /**
  * {@link java.util.ServiceLoader} service implementation of {@link io.helidon.tracing.spi.TracerProvider} for Open Tracing
  * tracers.
+ * <p>
+ *     When dealing with the global tracer, manage both the Helidon one and also the OpenTracing one in concert, whether
+ *     defaulting them or assigning them via {@link #global(io.helidon.tracing.Tracer)}.
+ * </p>
  */
 @Weight(Weighted.DEFAULT_WEIGHT - 50) // low weight, so it is easy to override
 public class OpenTracingTracerProvider implements TracerProvider {
 
     private static final LazyValue<List<SpanListener>> SPAN_LISTENERS =
             LazyValue.create(() -> HelidonServiceLoader.create(ServiceLoader.load(SpanListener.class)).asList());
 
+    private LazyValue<Tracer> globalHelidonTracer = LazyValue.create(() -> {
+        Config tracingConfig = GlobalConfig.config().get("tracing");
+
+        // Set up to create an explicit OpenTracing tracer only if we have config for tracing, indicating that the user wants
+        // something other than the no-op implementation.
+        if (tracingConfig.exists()) {
+            io.opentracing.Tracer openTracingTracer = OpenTracingTracerBuilder.create(tracingConfig)
+                    .build();
+            GlobalTracer.registerIfAbsent(openTracingTracer);
+        }
+        return OpenTracingTracer.create(GlobalTracer.get());
+    });
+
     @Override
     public TracerBuilder<?> createBuilder() {
         return OpenTracingTracer.builder();
     }
 
     @Override
     public Tracer global() {
-        return OpenTracingTracer.create(GlobalTracer.get());
+        return globalHelidonTracer.get();
     }
 
     @Override
     public void global(Tracer tracer) {
         if (tracer instanceof OpenTracingTracer opt) {
-            GlobalTracer.registerIfAbsent(opt.openTracing());
+            GlobalTracer.registerIfAbsent(() -> {
+                io.opentracing.Tracer openTracingTracer = opt.openTracing();
+                globalHelidonTracer = LazyValue.create(OpenTracingTracer.create(openTracingTracer));
+                return openTracingTracer;
+            });
         }
     }
 

tracing/providers/zipkin/pom.xml

@@ -57,6 +57,10 @@
             <groupId>io.opentracing.brave</groupId>
             <artifactId>brave-opentracing</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.helidon.common</groupId>
+            <artifactId>helidon-common-context</artifactId>
+        </dependency>
         <dependency>
             <groupId>io.helidon.common.features</groupId>
             <artifactId>helidon-common-features-api</artifactId>
@@ -138,17 +142,33 @@
                 </dependencies>
             </plugin>
             <!--
-                Because the Helidon Zipkin provider does not itself implement the Helidon tracing API (it does so through
-                OpenTracing), exempt this build from a test that requires that.
+               The propagation test expects the global tracer to be enabled. Other tests run with their own explicit config which
+               might have disabled the global tracer, so run the propagation test separately.
             -->
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
-                <configuration>
-                    <excludes>
-                        <exclude>io.helidon.tracing.providers.tests.TestTracerAndSpanPropagation.java</exclude>
-                    </excludes>
-                </configuration>
+                <executions>
+                    <execution>
+                        <id>default-test</id>
+                        <configuration>
+                            <excludes>
+                                <exclude>io.helidon.tracing.providers.tests.TestTracerAndSpanPropagation.java</exclude>
+                            </excludes>
+                        </configuration>
+                    </execution>
+                    <execution>
+                        <id>zipkin-propagation-test</id>
+                        <goals>
+                            <goal>test</goal>
+                        </goals>
+                        <configuration>
+                            <includes>
+                                <include>io.helidon.tracing.providers.tests.TestTracerAndSpanPropagation.java</include>
+                            </includes>
+                        </configuration>
+                    </execution>
+                </executions>
             </plugin>
         </plugins>
     </build>

tracing/providers/zipkin/src/main/java/io/helidon/tracing/providers/zipkin/ZipkinDataPropagationProvider.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2024 Oracle and/or its affiliates.
+ *
+ * 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
+ *
+ *     http://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.helidon.tracing.providers.zipkin;
+
+import io.helidon.common.context.Contexts;
+import io.helidon.common.context.spi.DataPropagationProvider;
+
+import io.opentracing.Scope;
+import io.opentracing.Span;
+import io.opentracing.Tracer;
+import io.opentracing.util.GlobalTracer;
+
+/**
+ * Data propagation provider for the Helidon Zipkin tracing provider.
+ */
+public class ZipkinDataPropagationProvider implements DataPropagationProvider<ZipkinDataPropagationProvider.ZipkinContext> {
+
+    private static final System.Logger LOGGER = System.getLogger(ZipkinDataPropagationProvider.class.getName());
+
+    /**
+     * Creates new provider; public for service loading.
+     */
+    public ZipkinDataPropagationProvider() {
+    }
+
+    @Override
+    public ZipkinContext data() {
+        Tracer tracer = Contexts.context()
+                .flatMap(ctx -> ctx.get(Tracer.class))
+                .orElseGet(GlobalTracer::get);
+        Span span = tracer.activeSpan();
+        return new ZipkinContext(tracer, span);
+    }
+
+    @Override
+    public void propagateData(ZipkinContext data) {
+        if (data != null && data.span != null) {
+            data.scope = data.tracer.activateSpan(data.span);
+        }
+    }
+
+    @Override
+    public void clearData(ZipkinContext data) {
+        if (data != null && data.scope != null) {
+            try {
+                data.scope.close();
+            } catch (Exception e) {
+                LOGGER.log(System.Logger.Level.TRACE, "Cannot close tracing span", e);
+            }
+        }
+    }
+
+    /**
+     * Zipkin-specific propagation context.
+     */
+    static class ZipkinContext {
+
+        private final Tracer tracer;
+        private final Span span;
+        private Scope scope;
+
+        private ZipkinContext(Tracer tracer, Span span) {
+            this.tracer = tracer;
+            this.span = span;
+        }
+    }
+}

tracing/providers/zipkin/src/main/java/io/helidon/tracing/providers/zipkin/ZipkinTracerProvider.java

@@ -48,6 +48,12 @@ public class ZipkinTracerProvider implements OpenTracingProvider {
     private static final List<String> TRACING_CONTEXT_PROPAGATION_HEADERS =
             List.of(X_OT_SPAN_CONTEXT, X_B3_TRACE_ID, X_B3_SPAN_ID, X_B3_PARENT_SPAN_ID, X_B3_SAMPLED, X_B3_FLAGS);
 
+    /**
+     * Public constructor for service loading.
+     */
+    public ZipkinTracerProvider() {
+    }
+
     @Override
     public ZipkinTracerBuilder createBuilder() {
         return ZipkinTracerBuilder.create();

tracing/providers/zipkin/src/main/java/module-info.java

@@ -30,6 +30,7 @@
     requires brave.opentracing;
     requires brave;
     requires io.helidon.common;
+    requires io.helidon.common.context;
     requires io.helidon.tracing.providers.opentracing;
     requires io.opentracing.noop;
     requires io.opentracing.util;
@@ -51,4 +52,6 @@
     provides io.helidon.tracing.providers.opentracing.spi.OpenTracingProvider
             with io.helidon.tracing.providers.zipkin.ZipkinTracerProvider;
 
+    provides io.helidon.common.context.spi.DataPropagationProvider
+            with io.helidon.tracing.providers.zipkin.ZipkinDataPropagationProvider;
 }

tracing/providers/zipkin/src/test/resources/application.yaml

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2017, 2023 Oracle and/or its affiliates.
+# Copyright (c) 2017, 2024 Oracle and/or its affiliates.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -45,4 +45,5 @@ tracing:
     int-tags:
       tag5: 145
       tag6: 741
-
+  # With changes to OpenTracing global tracer handling, provide a service name for the Zipkin implementation to use.
+  service: "helidon-test-service"