Add Zipkin UI to webapp (apache#10167)

.gitignore

@@ -21,4 +21,4 @@ oap-server/oal-grammar/**/gen/
 
 # This serves as a template but will ONLY be updated when building a source release tar,
 # so we don't track future updates of this file.
-oap-server/server-starter/src/main/resources/version.properties
+oap-server/server-starter/src/main/resources/version.properties

apm-webapp/pom.xml

@@ -71,6 +71,11 @@
             <artifactId>log4j-slf4j-impl</artifactId>
         </dependency>
 
+        <dependency>
+            <groupId>io.zipkin</groupId>
+            <artifactId>zipkin-lens</artifactId>
+        </dependency>
+
         <dependency>
             <groupId>com.linecorp.armeria</groupId>
             <artifactId>armeria</artifactId>

apm-webapp/src/main/java/org/apache/skywalking/oap/server/webapp/ApplicationStartUp.java

@@ -20,14 +20,11 @@
 
 import static org.yaml.snakeyaml.env.EnvScalarConstructor.ENV_FORMAT;
 import static org.yaml.snakeyaml.env.EnvScalarConstructor.ENV_TAG;
-
 import java.util.Collections;
-
 import org.yaml.snakeyaml.LoaderOptions;
 import org.yaml.snakeyaml.TypeDescription;
 import org.yaml.snakeyaml.Yaml;
 import org.yaml.snakeyaml.env.EnvScalarConstructor;
-
 import com.linecorp.armeria.common.SessionProtocol;
 import com.linecorp.armeria.server.HttpService;
 import com.linecorp.armeria.server.Server;
@@ -55,12 +52,25 @@ public static void main(String[] args) throws Exception {
             HttpFile
                 .of(ApplicationStartUp.class.getClassLoader(), "/public/index.html")
                 .asService();
+        final HttpService zipkinIndexPage =
+            HttpFile
+                .of(ApplicationStartUp.class.getClassLoader(), "/zipkin-lens/index.html")
+                .asService();
+
+        final ZipkinProxyService zipkin = new ZipkinProxyService(configuration.zipkinServices());
 
         Server
             .builder()
             .port(port, SessionProtocol.HTTP)
             .service("/graphql", new OapProxyService(oapServices))
             .service("/internal/l7check", HealthCheckService.of())
+            .service("/zipkin/config.json", zipkin)
+            .serviceUnder("/zipkin/api", zipkin)
+            .serviceUnder("/zipkin",
+                FileService.of(
+                    ApplicationStartUp.class.getClassLoader(),
+                    "/zipkin-lens")
+                    .orElse(zipkinIndexPage))
             .serviceUnder("/",
                 FileService.of(
                     ApplicationStartUp.class.getClassLoader(),

apm-webapp/src/main/java/org/apache/skywalking/oap/server/webapp/Configuration.java

@@ -31,6 +31,7 @@
 public class Configuration {
   private String serverPort;
   private String oapServices;
+  private String zipkinServices;
 
   public int port() {
     return serverPort == null || serverPort.trim().length() == 0
@@ -44,4 +45,11 @@ public String[] oapServices() {
     }
     return oapServices.split(",");
   }
+
+  public String[] zipkinServices() {
+    if (zipkinServices == null || zipkinServices.trim().length() == 0) {
+      throw new IllegalArgumentException("zipkinServices cannot be null or empty");
+    }
+    return zipkinServices.split(",");
+  }
 }

apm-webapp/src/main/java/org/apache/skywalking/oap/server/webapp/ZipkinProxyService.java

@@ -0,0 +1,67 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.skywalking.oap.server.webapp;
+
+import static java.util.stream.Collectors.toList;
+import java.net.URI;
+import java.util.List;
+import java.util.stream.Stream;
+import com.linecorp.armeria.client.Endpoint;
+import com.linecorp.armeria.client.WebClient;
+import com.linecorp.armeria.client.endpoint.EndpointGroup;
+import com.linecorp.armeria.client.endpoint.EndpointSelectionStrategy;
+import com.linecorp.armeria.client.logging.LoggingClient;
+import com.linecorp.armeria.common.HttpRequest;
+import com.linecorp.armeria.common.HttpResponse;
+import com.linecorp.armeria.common.SessionProtocol;
+import com.linecorp.armeria.server.AbstractHttpService;
+import com.linecorp.armeria.server.ServiceRequestContext;
+import lombok.SneakyThrows;
+
+public final class ZipkinProxyService extends AbstractHttpService {
+    private final WebClient loadBalancingClient;
+
+    public ZipkinProxyService(String[] zipkinServices) throws Exception {
+        final List<Endpoint> endpoints =
+            Stream
+                .of(zipkinServices)
+                .map(URI::create)
+                .map(URI::getAuthority)
+                .map(Endpoint::parse)
+                .collect(toList());
+        loadBalancingClient = newLoadBalancingClient(
+            EndpointGroup.of(
+                EndpointSelectionStrategy.roundRobin(),
+                endpoints));
+    }
+
+    @SneakyThrows
+    private static WebClient newLoadBalancingClient(EndpointGroup zipkinGroup) {
+        return WebClient
+            .builder(SessionProtocol.HTTP, zipkinGroup)
+            .decorator(LoggingClient.newDecorator())
+            .build();
+    }
+
+    @Override
+    protected HttpResponse doGet(ServiceRequestContext ctx, HttpRequest req) throws Exception {
+        return loadBalancingClient.execute(req);
+    }
+}

apm-webapp/src/main/resources/application.yml

@@ -18,3 +18,5 @@ serverPort: ${SW_SERVER_PORT:-8080}
 
 # Comma seperated list of OAP addresses.
 oapServices: ${SW_OAP_ADDRESS:-http://localhost:12800}
+
+zipkinServices: ${SW_ZIPKIN_ADDRESS:-http://localhost:9412}

dist-material/release-docs/LICENSE

@@ -340,6 +340,7 @@ The text of each license is the standard Apache 2.0 license.
     https://mvnrepository.com/artifact/io.vavr/vavr/0.10.3 Apache-2.0
     https://mvnrepository.com/artifact/io.vavr/vavr-match/0.10.3 Apache-2.0
     https://mvnrepository.com/artifact/io.zipkin.zipkin2/zipkin/2.23.16 Apache-2.0
+    https://mvnrepository.com/artifact/io.zipkin/zipkin-lens/2.23.16 Apache-2.0
     https://mvnrepository.com/artifact/javax.inject/javax.inject/1 Apache-2.0
     https://mvnrepository.com/artifact/joda-time/joda-time/2.10.5 Apache-2.0
     https://mvnrepository.com/artifact/net.jodah/failsafe/2.3.4 Apache-2.0
@@ -637,3 +638,6 @@ The text of each license is also included in licenses/LICENSE-[project].txt.
 
     https://mvnrepository.com/artifact/org.reactivestreams/reactive-streams/1.0.4 https://spdx.org/licenses/MIT-0.html
 
+=======================================================================
+The zipkin-lens.jar dependency has more front-end dependencies in it and the front-end dependencies' licenses
+are listed in zipkin-LICENSE.

dist-material/release-docs/LICENSE.tpl

@@ -31,3 +31,6 @@ The text of each license is also included in licenses/LICENSE-[project].txt.
       {{- end }}
     {{- end }}
 {{ end }}
+=======================================================================
+The zipkin-lens.jar dependency has more front-end dependencies in it and the front-end dependencies' licenses
+are listed in zipkin-LICENSE.