Polish code and demo of Sentinel Zuul 2.x adapter

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

sentinel-adapter/sentinel-zuul2-adapter/README.md

@@ -3,11 +3,11 @@
 This adapter provides **route level** and **customized API level**
 flow control for Zuul 2.x API Gateway.
 
-> *Note*: this adapter only support Zuul 2.x.
+> *Note*: this adapter only supports Zuul 2.x.
 
 ## How to use
 
-> You can refer to demo `sentinel-demo-zuul2-gateway`
+> You can refer to demo [`sentinel-demo-zuul2-gateway`](https://github.com/alibaba/Sentinel/tree/master/sentinel-demo/sentinel-demo-zuul2-gateway).
 
 1. Add Maven dependency to your `pom.xml`:
 
@@ -29,9 +29,9 @@ filterMultibinder.addBinding().toInstance(new SentinelZuulEndpoint());
 
 ## How it works
 
-As Zuul 2.x is based on netty, a event-drive model, so we use `AsyncEntry` to do flow control.
+As Zuul 2.x is based on Netty, an event-driven asynchronous model, so we use `AsyncEntry`.
 
-- `SentinelZuulInboundFilter`: This inbound filter will regard all proxy ID (`proxy` in `SessionContext`) and all customized API as resources. When a `BlockException` caught, the filter will set endpoint to find a fallback to execute.
+- `SentinelZuulInboundFilter`: This inbound filter will regard all routes (`routeVIP` in `SessionContext` by default) and all customized API as resources. When a `BlockException` caught, the filter will set endpoint to find a fallback to execute.
 - `SentinelZuulOutboundFilter`: When the response has no exception caught, the post filter will trace the exception and complete the entries.
 - `SentinelZuulEndpoint`: When an exception is caught, the filter will find a fallback to execute.
 
@@ -40,6 +40,8 @@ As Zuul 2.x is based on netty, a event-drive model, so we use `AsyncEntry` to do
 1. Start [Sentinel Dashboard](https://github.com/alibaba/Sentinel/wiki/Dashboard).
 2. You can configure the rules in Sentinel dashboard or via dynamic rule configuration.
 
+> You may need to add `-Dcsp.sentinel.app.type=1` property to mark this application as API gateway.
+
 ## Fallbacks
 
 You can implement `ZuulBlockFallbackProvider` to define your own fallback provider when Sentinel `BlockException` is thrown.
@@ -86,16 +88,3 @@ Default block response:
     "route":"/"
 }
 ```
-
-## Request origin parser
-
-You can register customized request origin parser like this:
-
-```java
-public class MyRequestOriginParser implements RequestOriginParser {
-    @Override
-    public String parseOrigin(HttpRequestMessage request) {
-        return request.getInboundRequest().getOriginalHost() + ":" + request.getInboundRequest().getOriginalPort();
-    }
-}
-```

sentinel-adapter/sentinel-zuul2-adapter/pom.xml

@@ -41,6 +41,7 @@
             </exclusions>
         </dependency>
 
+        <!-- The Spring library is introduced for AntMatcher -->
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-core</artifactId>

sentinel-adapter/sentinel-zuul2-adapter/src/main/java/com/alibaba/csp/sentinel/adapter/gateway/zuul2/HttpRequestMessageItemParser.java

@@ -1,8 +1,27 @@
+/*
+ * Copyright 1999-2019 Alibaba Group Holding Ltd.
+ *
+ * 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
+ *
+ *      https://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 com.alibaba.csp.sentinel.adapter.gateway.zuul2;
 
 import com.alibaba.csp.sentinel.adapter.gateway.common.param.RequestItemParser;
 import com.netflix.zuul.message.http.HttpRequestMessage;
 
+/**
+ * @author wavesZh
+ * @since 1.7.2
+ */
 public class HttpRequestMessageItemParser implements RequestItemParser<HttpRequestMessage> {
 
     @Override

sentinel-adapter/sentinel-zuul2-adapter/src/main/java/com/alibaba/csp/sentinel/adapter/gateway/zuul2/api/ZuulApiDefinitionChangeObserver.java

@@ -22,7 +22,7 @@
 
 /**
  * @author Eric Zhao
- * @since 1.6.0
+ * @since 1.7.2
  */
 public class ZuulApiDefinitionChangeObserver implements ApiDefinitionChangeObserver {
 

sentinel-adapter/sentinel-zuul2-adapter/src/main/java/com/alibaba/csp/sentinel/adapter/gateway/zuul2/api/ZuulGatewayApiMatcherManager.java

@@ -26,6 +26,7 @@
 
 /**
  * @author wavesZh
+ * @since 1.7.2
  */
 public final class ZuulGatewayApiMatcherManager {
 

sentinel-adapter/sentinel-zuul2-adapter/src/main/java/com/alibaba/csp/sentinel/adapter/gateway/zuul2/constants/ZuulConstant.java → sentinel-adapter/sentinel-zuul2-adapter/src/main/java/com/alibaba/csp/sentinel/adapter/gateway/zuul2/constants/SentinelZuul2Constants.java

@@ -16,15 +16,14 @@
 
 package com.alibaba.csp.sentinel.adapter.gateway.zuul2.constants;
 
-
 /**
  * @author wavesZh
  */
-public class ZuulConstant {
+public class SentinelZuul2Constants {
     /**
-     * Zuul use Sentinel as default context when serviceId is empty.
+     * The default entrance (context) name when the routeId is empty.
      */
-    public static final String ZUUL_DEFAULT_CONTEXT = "zuul_default_context";
+    public static final String ZUUL_DEFAULT_CONTEXT = "zuul2_default_context";
     /**
      * Zuul context key for keeping Sentinel entries.
      */
@@ -36,5 +35,5 @@ public class ZuulConstant {
      */
     public static final String ZUUL_CTX_SENTINEL_BLOCKED_FLAG = "_sentinel_blocked_flag";
 
-    private ZuulConstant(){}
+    private SentinelZuul2Constants() {}
 }

sentinel-adapter/sentinel-zuul2-adapter/src/main/java/com/alibaba/csp/sentinel/adapter/gateway/zuul2/fallback/DefaultBlockFallbackProvider.java

@@ -19,7 +19,7 @@
 import com.alibaba.csp.sentinel.slots.block.BlockException;
 
 /**
- * Default Fallback provider for sentinel {@link BlockException}, {@literal *} meant for all routes.
+ * Default fallback provider for Sentinel {@link BlockException}, {@literal *} meant for all routes.
  *
  * @author tiger
  */
@@ -33,7 +33,7 @@ public String getRoute() {
     @Override
     public BlockResponse fallbackResponse(String route, Throwable cause) {
         if (cause instanceof BlockException) {
-            return new BlockResponse(429, "Sentinel block exception", route);
+            return new BlockResponse(429, "SentinelBlockException", route);
         } else {
             return new BlockResponse(500, "System Error", route);
         }

sentinel-adapter/sentinel-zuul2-adapter/src/main/java/com/alibaba/csp/sentinel/adapter/gateway/zuul2/filters/endpoint/SentinelZuulEndpoint.java

@@ -16,10 +16,11 @@
 
 package com.alibaba.csp.sentinel.adapter.gateway.zuul2.filters.endpoint;
 
-import com.alibaba.csp.sentinel.adapter.gateway.zuul2.constants.ZuulConstant;
+import com.alibaba.csp.sentinel.adapter.gateway.zuul2.constants.SentinelZuul2Constants;
 import com.alibaba.csp.sentinel.adapter.gateway.zuul2.fallback.BlockResponse;
 import com.alibaba.csp.sentinel.adapter.gateway.zuul2.fallback.ZuulBlockFallbackManager;
 import com.alibaba.csp.sentinel.adapter.gateway.zuul2.fallback.ZuulBlockFallbackProvider;
+
 import com.netflix.zuul.context.SessionContext;
 import com.netflix.zuul.filters.http.HttpSyncEndpoint;
 import com.netflix.zuul.message.http.HttpRequestMessage;
@@ -32,13 +33,14 @@
  * @author wavesZh
  */
 public class SentinelZuulEndpoint extends HttpSyncEndpoint {
+
     @Override
     public HttpResponseMessage apply(HttpRequestMessage request) {
         SessionContext context = request.getContext();
         Throwable throwable = context.getError();
-        String fallBackRoute = (String) context.get(ZuulConstant.ZUUL_CTX_SENTINEL_FALLBACK_ROUTE);
-        ZuulBlockFallbackProvider zuulBlockFallbackProvider = ZuulBlockFallbackManager.getFallbackProvider(
-                fallBackRoute);
+        String fallBackRoute = (String) context.get(SentinelZuul2Constants.ZUUL_CTX_SENTINEL_FALLBACK_ROUTE);
+        ZuulBlockFallbackProvider zuulBlockFallbackProvider = ZuulBlockFallbackManager
+            .getFallbackProvider(fallBackRoute);
         BlockResponse response = zuulBlockFallbackProvider.fallbackResponse(fallBackRoute, throwable);
         HttpResponseMessage resp = new HttpResponseMessageImpl(context, request, response.getCode());
         resp.setBodyAsText(response.toString());