基于Nacos如何通过Spring Cloud Gateway实现动态路由？

发布时间：2020-06-23 18:23:38 来源：亿速云阅读：928 作者：清晨栏目：编程语言

不懂基于Nacos如何通过Spring Cloud Gateway实现动态路由？？其实想解决这个问题也不难，下面让小编带着大家一起学习怎么去解决，希望大家阅读完这篇文章后大所收获。

简介

该文档主要介绍以Nacos为配置中心，实现Spring Cloud GateWay 实现动态路由的功能。Spring Cloud Gateway启动时候，就将路由配置和规则加载到内存里，无法做到不重启网关就可以动态的对应路由的配置和规则进行增加，修改和删除。通过nacos的配置下发的功能可以实现在不重启网关的情况下，实现动态路由。

集成

Spring Cloud GateWay集成

spring-cloud-starter-gateway:路由转发、请求过滤（权限校验、限流以及监控等）

spring-boot-starter-webflux:反应式Web框架

spring-boot-starter-actuator:监控系统健康

  <dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-gateway</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-webflux</artifactId>
		</dependency>

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

Nacos集成

nacos-client:nacos客户端，现在用比较新的版本0.9.0

  <dependency>
			<groupId>com.alibaba.nacos</groupId>
			<artifactId>nacos-client</artifactId>
			<version>0.9.0</version>
		</dependency>

动态路由

DynamicRouteServiceImpl:提供动态路由的基础方法，可通过获取bean操作该类的方法。该类提供新增路由、更新路由、删除路由，然后实现发布的功能。

@Service
public class DynamicRouteServiceImpl implements ApplicationEventPublisherAware {

  @Autowired
  private RouteDefinitionWriter routeDefinitionWriter;

  private ApplicationEventPublisher publisher;


  /**
   * 增加路由
   * @param definition
   * @return
   */
  public String add(RouteDefinition definition) {
    routeDefinitionWriter.save(Mono.just(definition)).subscribe();
    this.publisher.publishEvent(new RefreshRoutesEvent(this));
    return "success";
  }


  /**
   * 更新路由
   * @param definition
   * @return
   */
  public String update(RouteDefinition definition) {
    try {
      this.routeDefinitionWriter.delete(Mono.just(definition.getId()));
    } catch (Exception e) {
      return "update fail,not find route routeId: "+definition.getId();
    }
    try {
      routeDefinitionWriter.save(Mono.just(definition)).subscribe();
      this.publisher.publishEvent(new RefreshRoutesEvent(this));
      return "success";
    } catch (Exception e) {
      return "update route fail";
    }


  }
  /**
   * 删除路由
   * @param id
   * @return
   */
  public String delete(String id) {
    try {
      this.routeDefinitionWriter.delete(Mono.just(id));
      return "delete success";
    } catch (Exception e) {
      e.printStackTrace();
      return "delete fail";
    }

  }

  @Override
  public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {
    this.publisher = applicationEventPublisher;
  }

}

RouteDefinition：提供路由实体类，主要有predicates匹配来自用户的请求，filters服务路由

@Validated
public class RouteDefinition {
	@NotEmpty
	private String id = UUID.randomUUID().toString();

	@NotEmpty
	@Valid
	private List<PredicateDefinition> predicates = new ArrayList<>();

	@Valid
	private List<FilterDefinition> filters = new ArrayList<>();

	@NotNull
	private URI uri;

	private int order = 0;

	public RouteDefinition() {}

	public RouteDefinition(String text) {
		int eqIdx = text.indexOf("=");
		if (eqIdx <= 0) {
			throw new ValidationException("Unable to parse RouteDefinition text '" + text + "'" +
					", must be of the form name=value");
		}

		setId(text.substring(0, eqIdx));

		String[] args = tokenizeToStringArray(text.substring(eqIdx+1), ",");

		setUri(URI.create(args[0]));

		for (int i=1; i < args.length; i++) {
			this.predicates.add(new PredicateDefinition(args[i]));
		}
	}

	public String getId() {
		return id;
	}

	public void setId(String id) {
		this.id = id;
	}

	public List<PredicateDefinition> getPredicates() {
		return predicates;
	}

	public void setPredicates(List<PredicateDefinition> predicates) {
		this.predicates = predicates;
	}

	public List<FilterDefinition> getFilters() {
		return filters;
	}

	public void setFilters(List<FilterDefinition> filters) {
		this.filters = filters;
	}

	public URI getUri() {
		return uri;
	}

	public void setUri(URI uri) {
		this.uri = uri;
	}

	public int getOrder() {
		return order;
	}

	public void setOrder(int order) {
		this.order = order;
	}

	@Override
	public boolean equals(Object o) {
		if (this == o) return true;
		if (o == null || getClass() != o.getClass()) return false;
		RouteDefinition routeDefinition = (RouteDefinition) o;
		return Objects.equals(id, routeDefinition.id) &&
				Objects.equals(predicates, routeDefinition.predicates) &&
				Objects.equals(order, routeDefinition.order) &&
				Objects.equals(uri, routeDefinition.uri);
	}

	@Override
	public int hashCode() {
		return Objects.hash(id, predicates, uri);
	}

	@Override
	public String toString() {
		return "RouteDefinition{" +
				"id='" + id + '\'' +
				", predicates=" + predicates +
				", filters=" + filters +
				", uri=" + uri +
				", order=" + order +
				'}';
	}
}

NacosGatewayProperties:自定义属性绑定值，可通过配置文件配置属性。

@ConfigurationProperties(prefix="nacos", ignoreUnknownFields = true)
@Configuration
public class NacosGatewayProperties {

	private String address;
	
	private String dataId;
	
	private String groupId;
	
	private Long timeout;

	public String getAddress() {
		return address;
	}

	public void setAddress(String address) {
		this.address = address;
	}

	public String getDataId() {
		return dataId;
	}

	public void setDataId(String dataId) {
		this.dataId = dataId;
	}

	public String getGroupId() {
		return groupId;
	}

	public void setGroupId(String groupId) {
		this.groupId = groupId;
	}

	public Long getTimeout() {
		return timeout;
	}

	public void setTimeout(Long timeout) {
		this.timeout = timeout;
	}	
}

DynamicRouteServiceImplByNacos：实现runner，通过nacos下发动态路由配置

@Component
public class DynamicRouteServiceImplByNacos implements CommandLineRunner{

	@Autowired
  private DynamicRouteServiceImpl dynamicRouteService;

	@Autowired
  private NacosGatewayProperties nacosGatewayProperties;

  /**
   * 监听Nacos Server下发的动态路由配置
   * @param dataId
   * @param group
   */
  public void dynamicRouteByNacosListener (){
    try {
      ConfigService configService=NacosFactory.createConfigService(nacosGatewayProperties.getAddress());
      String content = configService.getConfig(nacosGatewayProperties.getDataId(), nacosGatewayProperties.getGroupId(), nacosGatewayProperties.getTimeout());
      System.out.println(content);
      configService.addListener(nacosGatewayProperties.getDataId(), nacosGatewayProperties.getGroupId(), new Listener() {
        @Override
        public void receiveConfigInfo(String configInfo) {
        	List<RouteDefinition> list = JsonUtils.toList(configInfo, RouteDefinition.class);
        	list.forEach(definition->{
        		dynamicRouteService.update(definition);
        	});
        }
        @Override
        public Executor getExecutor() {
          return null;
        }
      });
    } catch (NacosException e) {
      e.printStackTrace();
    }
  }

	@Override
	public void run(String... args) throws Exception {
    dynamicRouteByNacosListener();
		
	}
  
}

nacos配置下发