Add demo for Sentinel Spring Cloud Gateway adapter

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

sentinel-demo/pom.xml

@@ -32,6 +32,7 @@
         <module>sentinel-demo-command-handler</module>
         <module>sentinel-demo-spring-webflux</module>
         <module>sentinel-demo-apache-dubbo</module>
+        <module>sentinel-demo-spring-cloud-gateway</module>
     </modules>
 
     <dependencies>

sentinel-demo/sentinel-demo-spring-cloud-gateway/pom.xml

@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>sentinel-demo</artifactId>
+        <groupId>com.alibaba.csp</groupId>
+        <version>1.6.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>sentinel-demo-spring-cloud-gateway</artifactId>
+
+    <properties>
+        <java.source.version>1.8</java.source.version>
+        <java.target.version>1.8</java.target.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-starter-gateway</artifactId>
+            <version>2.1.1.RELEASE</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-webflux</artifactId>
+            <version>2.1.4.RELEASE</version>
+        </dependency>
+
+        <dependency>
+            <groupId>com.alibaba.csp</groupId>
+            <artifactId>sentinel-spring-cloud-gateway-adapter</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.alibaba.csp</groupId>
+            <artifactId>sentinel-transport-simple-http</artifactId>
+        </dependency>
+    </dependencies>
+</project>

sentinel-demo/sentinel-demo-spring-cloud-gateway/src/main/java/com/alibaba/csp/sentinel/demo/spring/sc/gateway/GatewayConfiguration.java

@@ -0,0 +1,142 @@
+/*
+ * 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.demo.spring.sc.gateway;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import javax.annotation.PostConstruct;
+
+import com.alibaba.csp.sentinel.adapter.gateway.common.SentinelGatewayConstants;
+import com.alibaba.csp.sentinel.adapter.gateway.common.api.ApiDefinition;
+import com.alibaba.csp.sentinel.adapter.gateway.common.api.ApiPathPredicateItem;
+import com.alibaba.csp.sentinel.adapter.gateway.common.api.ApiPredicateItem;
+import com.alibaba.csp.sentinel.adapter.gateway.common.api.GatewayApiDefinitionManager;
+import com.alibaba.csp.sentinel.adapter.gateway.common.rule.GatewayFlowRule;
+import com.alibaba.csp.sentinel.adapter.gateway.common.rule.GatewayParamFlowItem;
+import com.alibaba.csp.sentinel.adapter.gateway.common.rule.GatewayRuleManager;
+import com.alibaba.csp.sentinel.adapter.gateway.sc.SentinelGatewayFilter;
+import com.alibaba.csp.sentinel.adapter.gateway.sc.exception.SentinelGatewayBlockExceptionHandler;
+import com.alibaba.csp.sentinel.slots.block.RuleConstant;
+
+import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.cloud.gateway.filter.GlobalFilter;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.Ordered;
+import org.springframework.core.annotation.Order;
+import org.springframework.http.codec.ServerCodecConfigurer;
+import org.springframework.web.reactive.result.view.ViewResolver;
+
+/**
+ * @author Eric Zhao
+ */
+@Configuration
+public class GatewayConfiguration {
+
+    private final List<ViewResolver> viewResolvers;
+    private final ServerCodecConfigurer serverCodecConfigurer;
+
+    public GatewayConfiguration(ObjectProvider<List<ViewResolver>> viewResolversProvider,
+                                ServerCodecConfigurer serverCodecConfigurer) {
+        this.viewResolvers = viewResolversProvider.getIfAvailable(Collections::emptyList);
+        this.serverCodecConfigurer = serverCodecConfigurer;
+    }
+
+    @Bean
+    @Order(Ordered.HIGHEST_PRECEDENCE)
+    public SentinelGatewayBlockExceptionHandler sentinelGatewayBlockExceptionHandler() {
+        // Register the block exception handler for Spring Cloud Gateway.
+        return new SentinelGatewayBlockExceptionHandler(viewResolvers, serverCodecConfigurer);
+    }
+
+    @Bean
+    @Order(-1)
+    public GlobalFilter sentinelGatewayFilter() {
+        return new SentinelGatewayFilter();
+    }
+
+    @PostConstruct
+    public void doInit() {
+        initCustomizedApis();
+        initGatewayRules();
+    }
+
+    private void initCustomizedApis() {
+        Set<ApiDefinition> definitions = new HashSet<>();
+        ApiDefinition api1 = new ApiDefinition("some_customized_api")
+            .setPredicateItems(new HashSet<ApiPredicateItem>() {{
+                add(new ApiPathPredicateItem().setPattern("/ahas"));
+                add(new ApiPathPredicateItem().setPattern("/product/**")
+                    .setMatchStrategy(SentinelGatewayConstants.PARAM_MATCH_STRATEGY_PREFIX));
+            }});
+        ApiDefinition api2 = new ApiDefinition("another_customized_api")
+            .setPredicateItems(new HashSet<ApiPredicateItem>() {{
+                add(new ApiPathPredicateItem().setPattern("/**")
+                    .setMatchStrategy(SentinelGatewayConstants.PARAM_MATCH_STRATEGY_PREFIX));
+            }});
+        definitions.add(api1);
+        definitions.add(api2);
+        GatewayApiDefinitionManager.loadApiDefinitions(definitions);
+    }
+
+    private void initGatewayRules() {
+        Set<GatewayFlowRule> rules = new HashSet<>();
+        rules.add(new GatewayFlowRule("aliyun_route")
+            .setCount(10)
+            .setIntervalSec(1)
+        );
+        rules.add(new GatewayFlowRule("aliyun_route")
+            .setCount(2)
+            .setIntervalSec(2)
+            .setBurst(2)
+            .setParamItem(new GatewayParamFlowItem()
+                .setParseStrategy(SentinelGatewayConstants.PARAM_PARSE_STRATEGY_CLIENT_IP)
+            )
+        );
+        rules.add(new GatewayFlowRule("httpbin_route")
+            .setCount(10)
+            .setIntervalSec(1)
+            .setControlBehavior(RuleConstant.CONTROL_BEHAVIOR_RATE_LIMITER)
+            .setMaxQueueingTimeoutMs(600)
+            .setParamItem(new GatewayParamFlowItem()
+                .setParseStrategy(SentinelGatewayConstants.PARAM_PARSE_STRATEGY_HEADER)
+                .setFieldName("X-Sentinel-Flag")
+            )
+        );
+        rules.add(new GatewayFlowRule("httpbin_route")
+            .setCount(1)
+            .setIntervalSec(1)
+            .setParamItem(new GatewayParamFlowItem()
+                .setParseStrategy(SentinelGatewayConstants.PARAM_PARSE_STRATEGY_URL_PARAM)
+                .setFieldName("pa")
+            )
+        );
+
+        rules.add(new GatewayFlowRule("some_customized_api")
+            .setResourceMode(SentinelGatewayConstants.RESOURCE_MODE_CUSTOM_API_NAME)
+            .setCount(5)
+            .setIntervalSec(1)
+            .setParamItem(new GatewayParamFlowItem()
+                .setParseStrategy(SentinelGatewayConstants.PARAM_PARSE_STRATEGY_URL_PARAM)
+                .setFieldName("pn")
+            )
+        );
+        GatewayRuleManager.loadRules(rules);
+    }
+}

sentinel-demo/sentinel-demo-spring-cloud-gateway/src/main/java/com/alibaba/csp/sentinel/demo/spring/sc/gateway/GatewayDemoApplication.java

@@ -0,0 +1,38 @@
+/*
+ * 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.demo.spring.sc.gateway;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+/**
+ * <p>A demo for Spring Cloud Gateway.</p>
+ *
+ * <p>To integrate with Sentinel dashboard, you can run the demo with the parameters (an example):
+ * <code>-Dproject.name=spring-cloud-gateway -Dcsp.sentinel.dashboard.server=localhost:8080
+ * -Dcsp.sentinel.api.port=8720 -Dcsp.sentinel.app.type=1
+ * </code>
+ * </p>
+ *
+ * @author Eric Zhao
+ */
+@SpringBootApplication
+public class GatewayDemoApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(GatewayDemoApplication.class, args);
+    }
+}

sentinel-demo/sentinel-demo-spring-cloud-gateway/src/main/resources/application.yml

@@ -0,0 +1,23 @@
+server:
+  port: 8090
+spring:
+  application:
+    name: spring-cloud-gateway
+  cloud:
+    gateway:
+      enabled: true
+      discovery:
+        locator:
+          lower-case-service-id: true
+      routes:
+        # Add your routes here.
+        - id: aliyun_route
+          uri: https://www.aliyun.com/
+          predicates:
+            - Path=/product/**
+        - id: httpbin_route
+          uri: https://httpbin.org
+          predicates:
+            - Path=/httpbin/**
+          filters:
+            - RewritePath=/httpbin/(?<segment>.*), /$\{segment}