API网关小刀：spring cloud gateway、nacos、sentinel_nacos gateway sentinel配置-优快云博客

本文链接：https://blog.youkuaiyun.com/weixin_44365189/article/details/128786454

1.spring cloud gateway 搭建

spring cloud gateway 官网

需要特别注意的两点：

spring cloud gateway是基于SpringBoot2.x、SpringWebFlux和ProjectReactor构建。

Spring Cloud Gateway需要Spring Boot和Spring Webflux提供的Netty运行时。它在传统的Servlet容器中或作为WAR构建时不起作用。

1.1 gateway前置知识

a. gateway网关的工作流程如下图：

客户端向SpringCloudGateway发出请求。如果网关处理程序映射确定请求与路由匹配，则将其发送到网关Web处理程序。此处理程序通过特定于请求的筛选器链运行请求。过滤器被虚线分隔的原因是，过滤器可以在发送代理请求之前和之后运行逻辑。执行所有“预”过滤器逻辑。然后发出代理请求。发出代理请求后，运行“后”过滤器逻辑。

1.2 pom依赖

   <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-parent</artifactId>
                <version>Hoxton.SR8</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
            <version>2.2.6.RELEASE</version>
        </dependency>
    </dependencies>

1.3 yaml 配置

server:
  port: 17001

spring:
  cloud:
    gateway:
      routes:
        - id: after_route
          uri: http://localhost:9001/gateway
          predicates:
            - Path=/gateway/**
            - Method=POST
        - id: proxy_route
          uri: http://localhost:7001
          predicates:
            - Path=/test/**

1.4 测试

2. 集成nacos实现动态配置

2.1 下载nacos，启动部署，参考官网

关于配置文件的必要知识点

2.2 pom依赖

        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-alibaba-nacos-config</artifactId>
            <version>2.1.0.RELEASE</version>
        </dependency>

2.3 新建bootstrap 文件（格式可以是properties、yaml）

spring:
  application:
   # 应用的名称建议设置，因为涉及到nacos配置文件的命名
    name: api-gateway 
  cloud:
    nacos:
      config:
        server-addr: 127.0.0.1:8848
        file-extension: yaml
  profiles:
    active: dev

2.4 在服务启动类上增加配置自动刷新注解

3. 集成sentinel 实现限流熔断

3.1 sentinel介绍；主要实现服务的限流、熔断功能

工作流程详解，自行打开官网了解

3.2 pom依赖

     <!-- 引入sentinel进行服务降级熔断 -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
            <version>2.2.9.RELEASE</version>
        </dependency>
        <!-- gateway网关整合sentinel进行限流降级 -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-alibaba-sentinel-gateway</artifactId>
            <version>2.2.9.RELEASE</version>
        </dependency>

3.3 yaml配置

spring:
  cloud:
    sentinel:
      eager: true
      transport:
        port: 8719
        dashboard: localhost:8700
      scg:
        fallback:
          mode: response
          response-status: 426
          response-body: '{"code":1001,"msg":"请求过于频繁，请稍后重试","data":""}'

3.4 注入异常处理类ExceptionHandler和过滤器Filter


import com.alibaba.csp.sentinel.adapter.gateway.sc.SentinelGatewayFilter;
import com.alibaba.csp.sentinel.adapter.gateway.sc.exception.SentinelGatewayBlockExceptionHandler;
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;

import java.util.Collections;
import java.util.List;

@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(name = {"customer-sentinelGatewayFilter"})
    @Order(-1)
    public GlobalFilter sentinelGatewayFilter() {
        return new SentinelGatewayFilter();
    }
}

若低版本未成功，可尝试在启动时增加参数： -Dcsp.sentinel.app.type=1