SpringCloud Gateway实践

小灰灰 2022-09-02 13:55 168阅读 0赞

## 一、Gateway路由介绍 ##

路由(Route) 是 Gateway 中最基本的组件之一，是表示一个具体路由信息的载体。

### 1.1 路由涉及概念 ###

*  id：每个路由的唯一标识
 *  uri：路由指向的目标地址，支持负载均衡的微服务名和常规的http地址两种形式
 *  predicates： 断言的作用是进行条件判断，只有断言都返回真，才会真正地执行路由
 *  filters：可作为路由转发的前置和后置操作
 *  order：用于多个Route之间的排序，数值越小排序越靠前，匹配优先级越高

### 1.2 路由执行流程 ###

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*  Gateway Client向Gateway Server发送请求
 *  请求首先会被HttpWebHandlerAdapter进行提取组装成网关上下文
 *  然后网关的上下文会传递到DispatcherHandler，它负责将请求分发给RoutePredicateHandlerMapping
 *  RoutePredicateHandlerMapping负责路由查找，并根据路由断言判断路由是否可用
 *  如果过断言成功，由FilteringWebHandler创建过滤器链并调用
 *  请求会一次经过PreFilter–微服务–PostFilter的方法，最终返回响应

### 1.3 路由配置方法 ###

*  application.yml
 *  路由配置类

## 二、Gateway实践 ##

### 2.1 采用编写 application.yml 文件的方式 ###

#### 2.1.1 pom.xml ####

<?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">
        <modelVersion>4.0.0</modelVersion>
    
        <groupId>com.ume.qa</groupId>
        <artifactId>SpringCloudGateway</artifactId>
        <version>1.0-SNAPSHOT</version>
    
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <java.version>1.8</java.version>
            <spring-cloud.version>3.0.1</spring-cloud.version>
        </properties>
    
        <dependencies>
            <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-webflux</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-gateway</artifactId>
                <version>3.0.3</version>
            </dependency>
            
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
                <exclusions>
                    <exclusion>
                        <artifactId>spring-cloud-context</artifactId>
                        <groupId>org.springframework.cloud</groupId>
                    </exclusion>
                    <exclusion>
                        <artifactId>spring-cloud-commons</artifactId>
                        <groupId>org.springframework.cloud</groupId>
                    </exclusion>
                    <exclusion>
                        <artifactId>spring-cloud-starter</artifactId>
                        <groupId>org.springframework.cloud</groupId>
                    </exclusion>
                </exclusions>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-bootstrap</artifactId>
                <version>3.0.1</version>
            </dependency>
    
            
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-openfeign</artifactId>
                <version>3.0.2</version>
                <exclusions>
                    <exclusion>
                        <artifactId>spring-cloud-commons</artifactId>
                        <groupId>org.springframework.cloud</groupId>
                    </exclusion>
                    <exclusion>
                        <artifactId>spring-cloud-starter</artifactId>
                        <groupId>org.springframework.cloud</groupId>
                    </exclusion>
                </exclusions>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-loadbalancer</artifactId>
                <version>3.0.2</version>
                <exclusions>
                    <exclusion>
                        <artifactId>spring-cloud-commons</artifactId>
                        <groupId>org.springframework.cloud</groupId>
                    </exclusion>
                    <exclusion>
                        <artifactId>spring-cloud-context</artifactId>
                        <groupId>org.springframework.cloud</groupId>
                    </exclusion>
                </exclusions>
            </dependency>
        </dependencies>
    
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-dependencies</artifactId>
                    <version>2.4.2</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-dependencies-parent</artifactId>
                    <version>${spring-cloud.version}</version>
                    <type>pom</type>
                </dependency>
                <dependency>
                    <groupId>com.alibaba.cloud</groupId>
                    <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                    <version>2.2.5.RELEASE</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
            </dependencies>
        </dependencyManagement>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    </project>

#### 2.1.2 application.yml ####

server:
      port: 8888
    
    spring:
      application:
        name: SpringCloudGateway
    
      cloud:
        nacos:
          discovery:
            server-addr: 172.24.xxx.xxx:8848 # Nacos 服务注册中心地址
    
        gateway:
          discovery:
            locator:
              #开启gateway从nacos上获取服务列表
              enabled: true
              lower-case-service-id: true
          routes:                       # 路由数组[路由 就是指定当请求满足什么条件的时候转到哪个微服务]
            - id: product_route          # 当前路由的标识, 要求唯一
              uri: lb://TestEnvToolsCommonApi  # lb指的是从nacos中按照名称获取微服务,并遵循负载均衡策略
    # uri: http://172.xxx.86.xxx:8002 # lb指的是从nacos中按照名称获取微服务,并遵循负载均衡策略
              predicates:                # 断言(就是路由转发要满足的条件)
                - Path=/api/testenvtools/**       # 当请求路径满足Path指定的规则时,才进行路由转发
    # filters: # 过滤器,请求在传递过程中可以通过过滤器对其进行一定的修改
    # - StripPrefix=1 # 转发之前去掉1层路径
    # - id: order_route
    # uri: lb://SpringCloudGateway
    # predicates:
    # - Path=/api/trolleytool/**
    ## filters:
    ## - StripPrefix=1
    
    logging:
      level:
        org:
          springframework:
            cloud:
              gateway: TRACE
    
    management:
      endpoints:
        web:
          exposure:
            include: '*'

#### 2.1.3 程序入口文件 ####

package com.ume.qa.gateway;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    
    @EnableDiscoveryClient
    @SpringBootApplication
    public class SpringCloudGatewayApplication { 
    	public static void main(String[] args) { 
    		SpringApplication.run(SpringCloudGatewayApplication.class, args);
    	}
    }

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