19，微服務(wù)下使用網(wǎng)關(guān)Spring Cloud Gateway

網(wǎng)關(guān)可以將服務(wù)和外網(wǎng)進(jìn)行隔離起到一定的保護(hù)作用，同時服務(wù)間局域網(wǎng)通信更加便捷。而且在網(wǎng)關(guān)中可以做到限流，權(quán)限校驗(yàn)，使得服務(wù)更加專注自身的業(yè)務(wù)。比如說下單需要登錄權(quán)限。
spring cloud Gateway 工作原理


3424642-d460d9f63e1291bc.png

客戶端向spring cloud Gateway發(fā)送請求，如果請求與網(wǎng)關(guān)程序定義的路由匹配，則將其發(fā)送到網(wǎng)關(guān)web處理程序，此處理程序運(yùn)行特定的請求過濾鏈

過濾器之間用虛線分開的原因是過濾器可能會在發(fā)送代理請求之前或者之后執(zhí)行邏輯。所有"pre"過濾器先執(zhí)行，然后執(zhí)行代理請求，代理請求完成后，執(zhí)行post 過濾器邏輯。

項(xiàng)目構(gòu)成
項(xiàng)目 端口 描述
gateway-eureka-server 8080 服務(wù)注冊與發(fā)現(xiàn)
gateway-service 8081 服務(wù)
gateway-client 8082 網(wǎng)關(guān) gateway

gateway-eureka-server
pom文件

<?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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
<groupId>com.taotao</groupId>
    <artifactId>eureka-server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>eureka-server</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.RELEASE</spring-cloud.version>
    </properties>

    <dependencies>
    <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</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>
    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
        </repository>
    </repositories>

</project>

啟動項(xiàng)


@EnableEurekaServer
@SpringBootApplication
public class GatewayEurekaServerApplication {

    public static void main(String[] args) {
        SpringApplication.run(EurekaServerApplication.class, args);
    }

}

配置文件 application.yml

spring:
  application:
    name: gateway-eureka-server

server:
  port: 8080
eureka:
  instance:
    hostname: localhostname
  client:
    fetch-registry: false
    register-with-eureka: false
    service-url:
      defaultZone: http://localhost:8080/eureka/

訪問http://localhost:8080 注冊中心

gateway-service 項(xiàng)目
pom文件，

<?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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
<groupId>com.taotao</groupId>
    <artifactId>service-one</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>service-one</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.RELEASE</spring-cloud.version>
    </properties>
<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-config</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</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>

    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
        </repository>
    </repositories>


</project>

啟動類

@EnableEurekaClient
@SpringBootApplication
public class GatewayServiceApplication {

    public static void main(String[] args) {
        SpringApplication.run(ServiceOneApplication.class, args);
    }

}

配置文件 application.yml

spring:
  application:
    name: gateway-service
server:
  port: 8081

eureka:
  client:
    service-url:
      defaultZone: http://localhost:8080/eureka/

創(chuàng)建類控制器 HelloWorldController ,http://localhost:8081/user/who

@RequestMapping("/user")
@RestController
public class HelloWorldController{

    @RequestMapping("who")
    public String helloworld() {
          return "my name is liangwang";
    }
}

創(chuàng)建類控制器OrderController, http://localhost:8081/order/info

@RequestMapping("/order")
@RestController
public class OrderController {

    @RequestMapping("/info")
    public String orderInfo() {
        return "order info date : " + new Date().toString();
    }
}

gateway-client項(xiàng)目
pom文件

<?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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.taotao</groupId>
    <artifactId>gateway-client</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>gateway-client</name>
    <description>Demo project for Spring Boot</description>
<properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.RELEASE</spring-cloud.version>
    </properties>
    <dependencies>
        <!--使用gateway-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>
<dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
          <!---使用斷路器-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</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>
    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
        </repository>
    </repositories>

</project>

使用RouteLocator的Bean進(jìn)行路由轉(zhuǎn)發(fā)，將請求進(jìn)行處理，最后轉(zhuǎn)發(fā)到目標(biāo)的下游服務(wù)

@SpringBootApplication
public class GatewayClientApplication {

    @Value("${test.uri}")
    private String uri;

    @Bean
    public RouteLocator customRouteLocator(RouteLocatorBuilder builder) {
        return builder.routes()
                //basic proxy
                .route(r -> r.path("/order/**")
                        .uri(uri)
                ).build();
    }

    public static void main(String[] args) {
        SpringApplication.run(GatewayClientApplication.class, args);
    }
}

上面的代碼里是訪問http://localhost:8083/order/的時候，網(wǎng)關(guān)轉(zhuǎn)發(fā)到
http://gateway-service:8081/order/, gateway-service服務(wù)在eureka中有注冊，最終對應(yīng)的ip: port

使用配置文件
application.yml

test:
  uri: lb://gateway-service
spring:
  application:
    name: gateway-client
  cloud:
    gateway:
      routes:
      - id: route_service_one
        uri: ${test.uri} # uri以lb://開頭（lb代表從注冊中心獲取服務(wù)），后面接的就是你需要轉(zhuǎn)發(fā)到的服務(wù)名稱
        predicates:
        - Path=/user/**

server:
  port: 8083

logging:
  level:
    org.springframework.cloud.gateway: TRACE
    org.springframework.http.server.reactive: DEBUG
    org.springframework.web.reactive: DEBUG
    reactor.ipc.netty: DEBUG
eureka:
  client:
    service-url:
      defaultZone: http://localhost:8080/eureka/
  instance:
    prefer-ip-address: true

其中test.uri是自我定義的屬性： uri以lb://開頭（lb代表從注冊中心獲取服務(wù)），后面接的就是你需要轉(zhuǎn)發(fā)到的服務(wù)名稱，按照上面的配置是http://localhost:8083/user/** => http://gateway-service:8081/user/** 到此項(xiàng)目搭建完成，接下來進(jìn)行測試，依次啟動gateway-eureka-server ,gateway-service, gateway-client

訪問;

不啟用注冊中心

即使集成了eureka-client也可以不使用注冊中心，可以關(guān)閉

eureka.client.enabled=false

StripPreffix屬性的使用
按照上面的配置，每一個路由只能對應(yīng)有個控制器的轉(zhuǎn)發(fā)，不夠靈活，假如想讓userapi的請求都轉(zhuǎn)發(fā)到gateway-service 服務(wù)，比如：

spring:
  application:
    name: gateway-client
  cloud:
    gateway:
      routes:
      - id: route_service_one
        uri: ${test.uri} # uri以lb://開頭（lb代表從注冊中心獲取服務(wù)），后面接的就是你需要轉(zhuǎn)發(fā)到的服務(wù)名稱
        predicates:
        - Path=/userapi/**  #userapi
        filters:
        - StripPrefix=1 # 表示在轉(zhuǎn)發(fā)時去掉userapi

修改完配置，重啟：

使用Hystrix
在gateway-client項(xiàng)目中引入依賴

 <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
        </dependency>

在spring cloud gateway中可以使用hystrix。Hystrix 是spring cloud 中一個服務(wù)熔斷降級的組件，在微服務(wù)系統(tǒng)有著十分重要的作用。
Hystrix是 spring cloud gateway中是以filter的形式使用的，代碼如下：

@SpringBootApplication
public class GatewayClientApplication {

    @Value("${test.uri}")
    private String uri;

    @Bean
    public RouteLocator customRouteLocator(RouteLocatorBuilder builder) {
        return builder.routes()
                //basic proxy
                .route(r -> r.path("/order/**")
                        .uri(uri)
                )
                .route(r -> r.path("/user/**")
                        .filters(f -> f
                                .hystrix(config -> config
                                        .setName("myserviceOne")
                                        .setFallbackUri("forward:/user/fallback")))
                        .uri(uri)).build();
    }

    public static void main(String[] args) {
        SpringApplication.run(GatewayClientApplication.class, args);
    }
}

上面代碼中添加了一個路由并配置了hystrix的fallbackUri，新增加一個FallbackController控制器

@RestController
public class FallBackController {
    @RequestMapping("/user/fallback")
    public Mono<String> fallback() {
        return Mono.just("service error, jump fallback");
    }
}

重啟gateway-client項(xiàng)目，并關(guān)閉service-one服務(wù)，在瀏覽器訪問
http://localhost:8083/user/who

使用yml 配置Hystrix

spring:
  application:
    name: gateway-client
  cloud:
    gateway:
      routes:
      - id: route_service_one
        uri: ${test.uri} # uri以lb://開頭（lb代表從注冊中心獲取服務(wù)），后面接的就是你需要轉(zhuǎn)發(fā)到的服務(wù)名稱
        predicates:
        - Path=/userapi/**
        filters:
        - StripPrefix=1 # 表示在轉(zhuǎn)發(fā)時去掉userapi

      - id: userapi2_route
        uri: ${test.uri}
        predicates:
        - Path=/userapi2/**
        filters:
        - StripPrefix=1
        - name: Hystrix
          args:
            name: myfallbackcmd
            fallbackUri: forward:/user/fallback

在配置中增加了一個新的路由userapi2_route,還配置了Hystrix，當(dāng)發(fā)生錯誤時會轉(zhuǎn)發(fā)到 fallbackUri, 測試訪問 http://localhost:8083/userapi2/order/info

reference
Hystrix wiki
Spring Cloud Gateway
Redis RateLimiter
轉(zhuǎn)載Redis RateLimiter實(shí)現(xiàn)
轉(zhuǎn)載Spring Cloud Gateway 基礎(chǔ)使用

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