Gateway动态路由实现

一、Gateway路由主要有两种方式

1、用yml配置文件
  routes:
    - id: ijep-service-sys  #基础服务
      uri: lb://ijep-service-sys
      predicates:
        - Path=/api/sys/**
      filters:
        - StripPrefix=2
2、写在代码里
image.png

无论是哪一种,在启动网关后将无法修改路由配置,如有新服务要上线,则需要先把网关下线,修改 yml 配置后,再重启网关。

二、动态路由解析

Gateway网关启动时,路由信息默认会加载内存中,路由信息被封装到 RouteDefinition 对象中,配置多个RouteDefinition组成Gateway的路由系统。

package org.springframework.cloud.gateway.route; 
@Validated
public class RouteDefinition {

@NotEmpty
private String id = UUID.randomUUID().toString();

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

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

@NotNull
private URI uri;

private int order = 0;

public RouteDefinition() {
}

.....此处省略......

}
  • RouteDefinition中的字段与上面代码配置方式比较对应
package org.springframework.cloud.gateway.route;

import reactor.core.publisher.Flux;

/**
 * @author Spencer Gibb
*/
public interface RouteDefinitionLocator {
Flux getRouteDefinitions();
}

*RouteDefinitionLocator是个接口,在org.springframework.cloud.gateway.route包下,如果想查看网关中所有的路由信息,可以调用此方法;后面还有另外一种查看方式,是Spring Cloud Gateway 的Endpoint端点提供的方法

三、Gateway Endpoint 端点

Endpoint 端点有暴露路由信息、获取所有路由、刷新路由、查看单个路由、删除路由等方法,源码在 org.springframework.cloud.gateway.actuate.GatewayControllerEndpoint 中,访问端点中的方法需要修改pom和配置文件:
*添加pom文件依赖:

  
        org.springframework.boot
        spring-boot-starter-actuator
    

*yml配置

# 暴露端点
management:
 endpoints:
   web:
    exposure:
    include: '*'
 endpoint:
    health:
    show-details: always

四、动态路由实现

准备:
* Spring Cloud:Greenwich.SR1
* Spring Boot: 2.1.1.RELEASE
* 注册中心(Consul)
* 网关Gateway
* 业务服务(ijep-service-sys)

1、创建路由模型

*过滤器模型

public class GatewayFilterDefinition {
//Filter Name
private String name;

//对应的路由规则
private Map args = new LinkedHashMap<>();

   ......此处省略Get、Set方法......
}

*路由断言模型

public class GatewayPredicateDefinition {

//断言对应的Name
private String name;

//配置的断言规则
private Map args = new LinkedHashMap<>();
       
 ......此处省略Get、Set方法......
}

*路由模型

public class GatewayRouteDefinition {

//路由的Id
private String id;

//路由断言集合配置
private List predicates = new ArrayList<>();

//路由过滤器集合配置
private List filters = new ArrayList<>();

//路由规则转发的目标uri
private String uri;

//路由执行的顺序
private int order = 0;

......此处省略Get、Set方法......
}
2、编写态路由实现类,实现ApplicationEventPublisherAware接口
@Service
public class DynamicRouteServiceImpl implements ApplicationEventPublisherAware{

    @Autowired
    private RouteDefinitionWriter       routeDefinitionWriter;

    private ApplicationEventPublisher   publisher;

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

/**
 * 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 {
        delete(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 Mono> delete(String id) {
    return this.routeDefinitionWriter.delete(Mono.just(id)).then(Mono.defer(() -> {
        return Mono.just(ResponseEntity.ok().build());
    })).onErrorResume((t) -> {
        return t instanceof NotFoundException;
    }, (t) -> {
        return Mono.just(ResponseEntity.notFound().build());
    });
  }
}
3、编写API接口,实现动态路由功能
@RestController
@RequestMapping("/api/route")
public class RouteRestController {

   @Autowired
   private DynamicRouteServiceImpl dynamicRouteService;

/**
 * 增加路由
 * @param gatewayRouteDefinition 路由模型
 *  报文:{"filters":[{"name":"StripPrefix","args":{"_genkey_0":"2"}}],"id":"ijep-service-sys-hyk11","uri":"lb://ijep-service-sys","order":2,"predicates":[{"name":"Path","args":{"_genkey_0":"/api/hyk11/**"}}]}
 * @return
 */
@PostMapping("/add")
public RestResponse add(@RequestBody GatewayRouteDefinition gatewayRouteDefinition) {
    String flag = "fail";
    try
    {
        RouteDefinition definition = assembleRouteDefinition(gatewayRouteDefinition);
        flag = this.dynamicRouteService.add(definition);
    } catch (Exception e) {
        e.printStackTrace();
    }

    return RestResponseBuilder.restResponse().data(flag).build();
}


/**
 * 更新路由
 * @param gatewayRouteDefinition 路由模型
 *  报文:{"filters":[{"name":"StripPrefix","args":{"_genkey_0":"2"}}],"id":"ijep-service-sys-hyk11","uri":"lb://ijep-service-sys","order":2,"predicates":[{"name":"Path","args":{"_genkey_0":"/api/hyk11/**"}}]}
 * @return
 */
@PostMapping("/update")
public RestResponse update(@RequestBody GatewayRouteDefinition gatewayRouteDefinition) {

    RouteDefinition definition = assembleRouteDefinition(gatewayRouteDefinition);
    String flag = this.dynamicRouteService.update(definition);

    return RestResponseBuilder.restResponse().data(flag).build();
}

/**
 * 删除路由
 * @param id 路由Id
 * @return
 */
@DeleteMapping("/routes/{id}")
public RestResponse delete(@PathVariable String id) {

    Mono> responseEntityMono = this.dynamicRouteService.delete(id);
    return RestResponseBuilder.restResponse().data(responseEntityMono).build();
}


/**
 * 把传递进来的参数转换成路由对象
 * @param gatewayRouteDefinition 路由模型
 * @return
 */
private RouteDefinition assembleRouteDefinition(GatewayRouteDefinition gatewayRouteDefinition) {
    RouteDefinition definition = new RouteDefinition();
    definition.setId(gatewayRouteDefinition.getId());
    definition.setOrder(gatewayRouteDefinition.getOrder());

    //设置断言
    List pdList = new ArrayList<>();
    List gatewayPredicateDefinitionList = gatewayRouteDefinition.getPredicates();
    for (GatewayPredicateDefinition gpDefinition: gatewayPredicateDefinitionList) {
        PredicateDefinition predicate = new PredicateDefinition();
        predicate.setArgs(gpDefinition.getArgs());
        predicate.setName(gpDefinition.getName());
        pdList.add(predicate);
    }

    definition.setPredicates(pdList);

    //设置过滤器
    List filters = new ArrayList();
    List gatewayFilters = gatewayRouteDefinition.getFilters();
    for(GatewayFilterDefinition filterDefinition : gatewayFilters){
        FilterDefinition filter = new FilterDefinition();
        filter.setName(filterDefinition.getName());
        filter.setArgs(filterDefinition.getArgs());
        filters.add(filter);
    }
    definition.setFilters(filters);

    URI uri = null;
    if(gatewayRouteDefinition.getUri().startsWith("http")){
        uri = UriComponentsBuilder.fromHttpUrl(gatewayRouteDefinition.getUri()).build().toUri();
    }else{
        // uri为 lb://consumer-service 时使用下面的方法
        uri = URI.create(gatewayRouteDefinition.getUri());
    }
    definition.setUri(uri);
    return definition;
}
}
4、启动网关服务

查询所有的路由地址信息,访问地址:http://localhost:9000/actuator/gateway/routes

image.png

5、访问业务接口(ApiPost)
image.png
6、新增路由信息(ApiPost)
image.png
7、新增后,访问业务接口(ApiPost)
image.png

项目地址:无权访问

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