Dubbo Gateway - 网关设计

背景

先说结论：dubbo目前版本（2.7.1 & 3.X）无法使用开源网关组件。

为什么？

通过Dubbo服务与注册的设计可以看出Dubbo服务的基本特点：

1. 注册/发现对象 - Dubbo服务接口
2. 注册/发现载体 - Dubbo URL (元信息：接口、版本、分组等)

一个Dubbo URL示例 ↓↓↓

dubbo://192.168.50.233:20880/com.paranoia.api.HelloService?anyhost=true&application=dubbo-provider&bean.name=providers:dubbo:com.paranoia.api.HelloService&default.deprecated=false&default.dynamic=false&default.register=true&deprecated=false&dubbo=2.0.2&dynamic=false&generic=false&interface=com.paranoia.api.HelloService&methods=hello&pid=8744&register=true&release=2.7.1&side=provider&timestamp=1559126008855

也就可以看出Dubbo中没有微服务中服务自省的概念。

服务自省：简单讲就是微服务架构中，注册中心管理的对象是应用（服务），而非对外的服务接口。

Dubbo计划在2.7.3版本实现"服务自省"。

实现“服务自省”有什么好处？

• 拓展Dubbo生态，接洽SC生态的部分开源组件（eureka/consul、zuul/gateway、zipkin…）
• 降低Dubbo注册中心压力(一个服务/一个服务下N个service)

等不到，刚需?

Plan A:

Dubbo + SpringCloud + Zookeeper + Nacos

Plan B:

Dubbo + SpringCloud + Zookeeper

Plan C:

Dubbo(2.7.2) + SpringCloud + Nacos

Plan D:

Dubbo(2.7.3) + Spring-Cloud-Gateway + Nacos

拓展：为什么要把注册中心从 Zookeeper 迁移到 Nacos

从降低运维成本，提高服务稳定性的角度讲，我们不希望维护两套注册中心，所以我们最终好像大概也许可能要选择Plan B.

Dubbo2.7.2已经支持nacos的元数据配置，也就是说我们等六月初RELEASE正式发布，就可以使用一个Plan C : Dubbo+Sppring Cloud + Nacos 。 但无奈项目中使用的Dubbo 3.x版本并没有这个规划…,Plan D 也是这个问题

分层设计

graph TD;
    Spring-Cloud-Gateway-->facade-0;
    Spring-Cloud-Gateway-->facade-1;
    facade-0-->dubbo-provider-0;
    facade-0-->dubbo-provider-1;
    facade-1-->dubbo-provider-0;
    facade-1-->dubbo-provider-1;

可行性

Plan A : Dubbo+SpringCloud+Zookeeper+Nacos

dubbo-provider

pom

        <dependency>
            <groupId>com.paranoia</groupId>
            <artifactId>api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
        </dependency>
        <dependency>
            <groupId>com.github.sgroschupf</groupId>
            <artifactId>zkclient</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zookeeper-config</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.2</version>
        </dependency>

service

import org.apache.dubbo.config.annotation.Service;
@Service
public class HelloServiceImpl implements HelloService {
    public String hello(String name) {
        return "hi , how are you ? my friend " + name;
    }
}

启动类添加注解

@EnableDubbo(scanBasePackages = "com.paranoia.demo.service")

配置文件

server:
  port: 8081

spring:
  profiles:
    active: dev
  application:
    name: dubbo-provider
  cloud:
    zookeeper:
      client:
        sasl: false
      enabled: true
      connect-string: localhost:2181

dubbo:
  application.name: ${spring.application.name}
  registry.address: zookeeper://127.0.0.1:2181
  config-center.address: zookeeper://127.0.0.1:2181
  consumer.timeout: 3000

SCA-facade

pom：同时集成SpringCloud和Dubbo

<dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
            <version>0.9.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-commons</artifactId>
            <version>2.1.1.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!--dubbo-->
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
        </dependency>
        <dependency>
            <groupId>com.github.sgroschupf</groupId>
            <artifactId>zkclient</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zookeeper-config</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

        <!---->
        <dependency>
            <groupId>com.paranoia</groupId>
            <artifactId>api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

rest接口：使用dubbo-provider中的服务

import org.apache.dubbo.config.annotation.Reference;
@RestController
public class HelloController {

    @Reference
    HelloService helloService;

    @GetMapping("/hi")
    public String sayHi(@RequestParam String name) {
        System.out.println("SCA-facade get request name = " + name);
        return helloService.hello(name);
    }
}

启动类注解

@EnableDubbo
@EnableDiscoveryClient

配置文件
配置nacos作为CLoud的注册中心，
配置zk作为Dubbo的注册中心

spring:
  application:
    name: SCA-FACADE
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
    zookeeper:
      client:
        asl: false
      enabled: true
      connect-string: localhost:2181
server:
  port: 8084

management:
  endpoints:
    web:
      exposure:
        include: "*"

dubbo:
  application.name: ${spring.application.name}
  registry.address: zookeeper://127.0.0.1:2181
  config-center.address: zookeeper://127.0.0.1:2181
  consumer.timeout: 3000

SCA-gateway

我们采用Spring-Cloud-Gateway作为Cloud的网关

pom

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-gateway-webflux</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
            <version>0.9.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

启动类添加注解

@EnableDiscoveryClient

配置文件
这里我们添加一个routes规则：GET请求&&path="/hi"的请求转发到SCA-FACADE服务

server:
  port: 8083

management:
  endpoints:
    web:
      exposure:
        include: "*"

spring:
  application:
    name: SC-gateway
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
    gateway:
      default-filters:
      routes:
        - id: zk_route
          uri: lb://SCA-FACADE
            # path中是server服务中提供的接口
            # Method ： 指定访问的请求类型
          predicates:
              - Path=/hi
              - Method=GET

facade需要在底层服务启动之后再启动，否则nacos会寻址失败导致项目启动失败。

检验负载均衡

两个dubbo-provider服务，两个facde服务，一个gateway服务

多次请求网关地址：

curl http://47.106.221.***:8083/hi?name=dubbo-gateway

查看各个image控制台，发现无论是spring-cloud的还是dubbo的负载均衡都没有问题。

Plan B : Dubbo+SpringCloud+Zookeeper+Nacos

SC-facase-zk

相比Plan A ，facade只需要修改配置中心依赖以及配置文件

pom : 去掉naocs-dicovery 替换成 zk-discovery

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zookeeper-discovery</artifactId>
            <version>2.1.1.RELEASE</version>
        </dependency>

配置文件：

spring:
  application:
    name: SCA-FACADE-ZK
  cloud:
    #替换nacos为zk
    zookeeper:
      client:
        asl: false
      enabled: true
      connect-string: 47.106.221.253:2181
      discovery:
        enabled: true
        register: true

server:
  port: 8084

management:
  endpoints:
    web:
      exposure:
        include: "*"

dubbo:
  application.name: ${spring.application.name}
  registry.address: zookeeper://47.106.221.253:2181
  config-center.address: zookeeper://47.106.221.253:2181
  consumer.timeout: 3000

SC-gateway-zk

pom : 同SC-facade-zk

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zookeeper-discovery</artifactId>
            <version>2.1.1.RELEASE</version>
        </dependency>

配置文件

server:
  port: 8081

spring:
  application:
    name: dubbo-provider
  cloud:
    #替换nacos为zk
    zookeeper:
      client:
        sasl: false
      enabled: true
      connect-string: 47.106.221.253:2181

dubbo:
  application.name: ${spring.application.name}
  registry.address: zookeeper://47.106.221.253:2181
  config-center.address: zookeeper://47.106.221.253:2181
  consumer.timeout: 3000

启动服务dubbo-provider , sc-facase-zk , sc-gateway-zk

查看zk中数据：