跳到主要内容
  1. 服务网关特性
  2. 基于RestTemplate自定义服务网关
  3. Spring Cloud Netflix Zuul网关
  4. Spring Cloud Gateway网关

Spring Cloud服务网关

版本信息

Spring Cloud : Hoxton.SR1

Spring Boot : 2.2.2.RELEASE

Zookeeper : 3.5.6 （注册中心使用）

服务网关特性​

服务网关是干什么用的？

  • 认证
  • 安全（授权）
  • 动态路由

基于RestTemplate自定义服务网关​

服务端演示提供服务​

  1. 添加pom依赖

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>

    <!--zookeeper 客户端-->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-zookeeper-discovery</artifactId>
    </dependency>

  2. 服务网关服务应用GatewayServerApplication

    /**
     * 服务网关服务应用
     *
     * @author FelixFly <chenglinxu@yeah.net>
     * @date 2020/2/8
     */
    @SpringBootApplication
    public class GatewayServerApplication {

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

  3. 演示服务端点

    /**
     * 演示服务端点
     *
     * @author FelixFly <chenglinxu@yeah.net>
     * @date 2020/2/8
     */
    @RestController
    public class EchoController {

        @Autowired
        private Environment environment;


        @GetMapping("/echo")
        public String echo(String message) {
            // 由于采用的是随机端口，这地方必须采用这个方式获取端口
            String port = environment.getProperty("local.server.port");
            return "ECHO(" + port + "):" + message;
        }
    }

  4. 服务配置application.yml

    spring:
      application:
        name: gateway-server
      cloud:
        zookeeper:
          connect-string: 127.0.0.1:2181
    server:
      port: 0

启动服务，根据启动日志查看本地的随机端口，此次端口是54692

http://127.0.0.1:54692/echo?message=Hello 返回信息ECHO(54692):Hello

自定义服务网关​

基于Servlet

配置文件application.yml

spring:
  application:
    name: gateway-zuul
  cloud:
    zookeeper:
      connect-string: 127.0.0.1:2181
server:
  port: 7070

基于DiscoveryClient​

GatewayCustomServlet网关Servlet

包名：top.felixfly.cloud.gateway.custom

/**
 * 服务网关Servlet实现
 *
 * @author FelixFly <chenglinxu@yeah.net>
 * @date 2020/2/8
 */
@WebServlet(name = "gateway", urlPatterns = "/gateway/*")
public class GatewayCustomServlet extends HttpServlet {

    @Autowired
    private DiscoveryClient discoveryClient;

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 访问地址的Uri:/{service-name}/${service-uri}
        String pathInfo = req.getPathInfo();
        String[] paths = StringUtils.split(pathInfo.substring(1), "/");
        // 服务名称
        String serverName = paths[0];
        // 服务访问地址
        String serverURI = paths[1];
        // 获取服务实例
        ServiceInstance serviceInstance = choose(serverName);
        // 目标地址
        String targetURL = createTargetURL(serviceInstance, serverURI, req);
        RestTemplate restTemplate = new RestTemplate();
        String method = req.getMethod();
        ResponseEntity<byte[]> responseEntity = restTemplate
                .exchange(targetURL, HttpMethod.resolve(method), null, byte[].class);
        // 返回状态
        resp.setStatus(responseEntity.getStatusCodeValue());
        // 媒体类型
        HttpHeaders headers = responseEntity.getHeaders();
        MediaType contentType = headers.getContentType();
        if (Objects.nonNull(contentType)) {
            resp.setHeader(HttpHeaders.CONTENT_TYPE, contentType.toString());
        }
        // 返回内容
        byte[] body = responseEntity.getBody();
        if (Objects.nonNull(body)) {
            ServletOutputStream outputStream = resp.getOutputStream();
            outputStream.write(responseEntity.getBody());
            outputStream.flush();
        }
    }

    private String createTargetURL(ServiceInstance instance, String serverURI,
                                   HttpServletRequest req) {
        StringBuilder urlBuilder = new StringBuilder(64);
        return urlBuilder.append(instance.isSecure() ? "https" : "http").append("://")
                .append(instance.getHost()).append(":").append(instance.getPort())
                .append(serverURI).append("?").append(req.getQueryString())
                .toString();
    }

    private ServiceInstance choose(String serverName) {
        List<ServiceInstance> instances = this.discoveryClient.getInstances(serverName);
        if (CollectionUtils.isEmpty(instances)) {
            throw new RuntimeException("无服务实例");
        }
        int index = new Random().nextInt(instances.size());
        return instances.get(index);
    }
}

服务启动类GatewayZuulApplication

/**
 * 服务网关 Zuul 服务
 *
 * @author FelixFly <chenglinxu@yeah.net>
 * @date 2020/2/8
 */
@SpringBootApplication
@ServletComponentScan(basePackages = "top.felixfly.cloud.gateway.custom")
public class GatewayZuulApplication {

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

启动服务，访问地址http://127.0.0.1:7070/gateway/gateway-server/echo?message=hello

返回信息ECHO(54692):Hello

基于@LoadBlanced​

GatewayLoadBalancedServlet负载均衡Servlet

包名：top.felixfly.cloud.gateway.custom

/**
 * 服务网关基于LoadBalanced Servlet实现
 *
 * @author FelixFly <chenglinxu@yeah.net>
 * @date 2020/2/8
 */
@WebServlet(name = "gatewaylb", urlPatterns = "/gatewaylb/*")
public class GatewayLoadBalancedServlet extends HttpServlet {

    @Autowired
    @LoadBalanced
    private RestTemplate restTemplate;

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 访问地址的Uri:/{service-name}/${service-uri}
        String pathInfo = req.getPathInfo();
        // 目标地址
        String targetURL = "http://" + pathInfo.substring(1) + "?" + req.getQueryString();
        String method = req.getMethod();
        ResponseEntity<byte[]> responseEntity = restTemplate
                .exchange(targetURL, HttpMethod.resolve(method), null, byte[].class);
        // 返回状态
        resp.setStatus(responseEntity.getStatusCodeValue());
        // 媒体类型
        HttpHeaders headers = responseEntity.getHeaders();
        MediaType contentType = headers.getContentType();
        if (Objects.nonNull(contentType)) {
            resp.setHeader(HttpHeaders.CONTENT_TYPE, contentType.toString());
        }
        // 返回内容
        byte[] body = responseEntity.getBody();
        if (Objects.nonNull(body)) {
            ServletOutputStream outputStream = resp.getOutputStream();
            outputStream.write(responseEntity.getBody());
            outputStream.flush();
        }
    }
}

服务启动类GatewayZuulApplication

/**
 * 服务网关 Zuul 服务
 *
 * @author FelixFly <chenglinxu@yeah.net>
 * @date 2020/2/8
 */
@SpringBootApplication
@ServletComponentScan(basePackages = "top.felixfly.cloud.gateway.custom")
public class GatewayZuulApplication {

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

    @Bean
    @LoadBalanced
    public RestTemplate restTemplate(){
        return new RestTemplate();
    }
}

启动服务，访问地址http://127.0.0.1:7070/gatewaylb/gateway-server/echo?message=hello

返回信息ECHO(54692):Hello

配置文件application.yml调整

默认是启用ribbon进行负载均衡，可以关闭ribbon使用Spring Cloud LoadBalanced

spring:
  application:
    name: gateway-zuul
  cloud:
    zookeeper:
      connect-string: 127.0.0.1:2181
    loadbalancer:
      ribbon:
        enabled: false # 关闭Ribbon
server:
  port: 7070

Spring Cloud Netflix Zuul网关​

基本使用​

  1. 添加pom依赖

    <!--zuul 网关-->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
    </dependency>

  2. 启动类添加@EnableZuulProxy

    /**
     * 服务网关 Zuul 服务
     *
     * @author FelixFly <chenglinxu@yeah.net>
     * @date 2020/2/8
     */
    @SpringBootApplication
    @EnableZuulProxy
    @ServletComponentScan(basePackages = "top.felixfly.cloud.gateway.custom")
    public class GatewayZuulApplication {

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

        @Bean
        @LoadBalanced
        public RestTemplate restTemplate(){
            return new RestTemplate();
        }
    }

  3. 配置文件application.yml添加路由配置

    spring:
      application:
        name: gateway-zuul
      cloud:
        zookeeper:
          connect-string: 127.0.0.1:2181
        loadbalancer:
          ribbon:
            enabled: false # 关闭Ribbon
    server:
      port: 7070
    zuul:
      routes:
        gateway-server: /gateway-server/**

    默认不配置uri，自动启用负载均衡，直连配置

    zuul:
      routes:
        gateway-server:
          path: /gateway-server/**
          url: http://127.0.0.1:54692

启动服务，访问地址http://127.0.0.1:7070/gateway-server/echo?message=hello

返回信息ECHO(54692):Hello

原理分析​

@EnableZuulProxy注解

@EnableCircuitBreaker
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Import(ZuulProxyMarkerConfiguration.class)
public @interface EnableZuulProxy {

}

启用了服务熔断以及导入了ZuulProxyMarkerConfiguration

ZuulProxyMarkerConfiguration源码

@Configuration(proxyBeanMethods = false)
public class ZuulProxyMarkerConfiguration {

   @Bean
   public Marker zuulProxyMarkerBean() {
      return new Marker();
   }

   class Marker {

   }

}

注册了一个Marker的Bean，这个Bean会作为装配条件

ZuulProxyAutoConfiguration自动配置类

@Configuration(proxyBeanMethods = false)
@Import({ RibbonCommandFactoryConfiguration.RestClientRibbonConfiguration.class,
		RibbonCommandFactoryConfiguration.OkHttpRibbonConfiguration.class,
		RibbonCommandFactoryConfiguration.HttpClientRibbonConfiguration.class,
		HttpClientConfiguration.class })
@ConditionalOnBean(ZuulProxyMarkerConfiguration.Marker.class)
public class ZuulProxyAutoConfiguration extends ZuulServerAutoConfiguration {
	...
}

父类ZuulServerAutoConfiguration自动配置类

@Configuration(proxyBeanMethods = false)
@EnableConfigurationProperties({ ZuulProperties.class })
@ConditionalOnClass({ ZuulServlet.class, ZuulServletFilter.class })
@ConditionalOnBean(ZuulServerMarkerConfiguration.Marker.class)
// Make sure to get the ServerProperties from the same place as a normal web app would
// FIXME @Import(ServerPropertiesAutoConfiguration.class)
public class ZuulServerAutoConfiguration {

	...

    // 注册了一个ZuulController
	@Bean
	public ZuulController zuulController() {
		return new ZuulController();
	}

    // 在ZuulController加了ZuulHandlerMapping路由匹配
	@Bean
	public ZuulHandlerMapping zuulHandlerMapping(RouteLocator routes,
			ZuulController zuulController) {
		ZuulHandlerMapping mapping = new ZuulHandlerMapping(routes, zuulController);
		mapping.setErrorController(this.errorController);
		mapping.setCorsConfigurations(getCorsConfigurations());
		return mapping;
	}

	...

    // 注册了一个ZuulServlet
	@Bean
	@ConditionalOnMissingBean(name = "zuulServlet")
	@ConditionalOnProperty(name = "zuul.use-filter", havingValue = "false",
			matchIfMissing = true)
	public ServletRegistrationBean zuulServlet() {
		ServletRegistrationBean<ZuulServlet> servlet = new ServletRegistrationBean<>(
				new ZuulServlet(), this.zuulProperties.getServletPattern());
		// The whole point of exposing this servlet is to provide a route that doesn't
		// buffer requests.
		servlet.addInitParameter("buffer-requests", "false");
		return servlet;
	}

    

	...

}

从上可知：注册了ZuulController和ZuulServlet

  • ZuulController 访问地址针对的是根路径"/",也就是基本使用的地址

  • ZuulServlet 访问地址针对的是Servlet配置地址，默认是“/zuul”,如是访问地址更改为：http://127.0.0.1:7070/zuul/gateway-server/echo?message=hello也是可以返回正常结果

    返回信息ECHO(54692):Hello

核心api​

  • org.springframework.cloud.netflix.zuul.web.ZuulController Zuul网关的控制器，内部调用是ZuulServlet

  • com.netflix.zuul.http.ZuulServlet 网关的核心处理类

  • com.netflix.zuul.ZuulFilter 网关的过滤器，有如下类型

    • pre 前置过滤器
    • route 路由过滤器
    • post 后置过滤器
    • error 错误过滤器

  • org.springframework.cloud.netflix.zuul.filters.RouteLocator 路由列表加载器

    • org.springframework.cloud.netflix.zuul.filters.RefreshableRouteLocator 可刷新的路由列表加载器

    有两种实现：

    • org.springframework.cloud.netflix.zuul.filters.discovery.DiscoveryClientRouteLocator 服务发现路由列表加载器
    • org.springframework.cloud.netflix.zuul.filters.SimpleRouteLocator 本地配置的路由列表加载器

    默认实现:org.springframework.cloud.netflix.zuul.filters.CompositeRouteLocator

Spring Cloud Gateway网关​

基本使用​

  1. 添加pom依赖

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>

    <!--zookeeper 客户端-->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-zookeeper-discovery</artifactId>
    </dependency>
    <!--gateway 网关-->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-gateway</artifactId>
    </dependency>

  2. 服务应用启动类GatewayApplication

    /**
     * 服务网关应用服务
     *
     * @author FelixFly <chenglinxu@yeah.net>
     * @date 2020/2/9
     */
    @SpringBootApplication
    public class GatewayApplication {

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

  3. 配置文件application.yml（直连方式）

    spring:
      application:
        name: gateway-gateway
      cloud:
        zookeeper:
          connect-string: 127.0.0.1:2181
        loadbalancer:
          ribbon:
            enabled: false # 关闭Ribbon
        gateway:
          routes:
            - id: gateway-server
              uri: http://127.0.0.1:54692
              predicates:
              - Path=/gateway-server/**
              filters:
              - StripPrefix=1 #去掉Path一个/路径分割,http://127.0.0.1:54692/**

    server:
      port: 6060

    通过uri直连方式，访问地址：http://127.0.0.1:6060/gateway-server/echo?message=hello

    访问结果：ECHO(54692):hello

  4. 调整配置文件application.yml（服务发现方式）

    spring:
      application:
        name: gateway-gateway
      cloud:
        zookeeper:
          connect-string: 127.0.0.1:2181
        loadbalancer:
          ribbon:
            enabled: false # 关闭Ribbon
        gateway:
          routes:
            - id: gateway-server
              #uri: http://127.0.0.1:54692
              uri: lb://gateway-server
              predicates:
              - Path=/gateway-server/**
              filters:
              - StripPrefix=1 #去掉Path一个/路径分割,http://127.0.0.1:54692/**

    server:
      port: 6060

    服务发现方式（负载均衡），访问地址：http://127.0.0.1:6060/gateway-server/echo?message=hello

    访问结果：ECHO(54692):hello

核心api​

  • org.springframework.cloud.gateway.handler.predicate.RoutePredicateFactory 路由匹配工厂
    • PathRoutePredicateFactory 路径路由匹配
    • ...
  • org.springframework.cloud.gateway.filter.factory.GatewayFilterFactory 网关过滤器工厂
    • org.springframework.cloud.gateway.filter.factory.StripPrefixGatewayFilterFactory 去掉前缀过滤器工厂
    • ...
  • org.springframework.cloud.gateway.filter.GatewayFilter 网关过滤器
  • org.springframework.cloud.gateway.filter.GatewayFilterChain 网关过滤器的链
  • org.springframework.cloud.gateway.filter.GlobalFilter 全局的过滤器
    • org.springframework.cloud.gateway.filter.ReactiveLoadBalancerClientFilter 负载均衡的过滤器
    • ...
  • org.springframework.cloud.gateway.route.RouteDefinition 路由信息的定义
  • org.springframework.cloud.gateway.route.RouteDefinitionLocator 路由信息加载器
  • org.springframework.cloud.gateway.route.RouteDefinitionRepository 路由信息的仓储