SpringCloud Gateway 在不重启网关服务的前提下，实现添加服务路由零配置升级

zuul:
 ignored-services: '*'
 routes:
    ddc:
      path: /ddc/**
      serviceId: portal-ddc
    pcm:
      path: /pcm/**
      serviceId: portal-pcm

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

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

 @SpringBootApplication
 public class DemogatewayApplication {

 @Bean
 public RouteLocator customRouteLocator(RouteLocatorBuilder builder) {
   return builder.routes()
     .route("path_route", r -> r.path("/get")
     .uri("http://httpbin.org"))
     .route("host_route", r -> r.host("*.myhost.org")
     .uri("http://httpbin.org"))
     .route("rewrite_route", r -> r.host("*.rewrite.org")
     .filters(f -> f.rewritePath("/foo/(?<segment>.*)", "/${segment}"))
     .uri("http://httpbin.org"))
     .route("hystrix_route", r -> r.host("*.hystrix.org")
     .filters(f -> f.hystrix(c -> c.setName("slowcmd")))
     .uri("http://httpbin.org"))
     .route("hystrix_fallback_route", r -> r.host("*.hystrixfallback.org")
     .filters(f -> f.hystrix(c -> c.setName("slowcmd").setFallbackUri("forward:/hystrixfallback")))
     .uri("http://httpbin.org"))
     .route("limit_route", r -> r
     .host("*.limited.org").and().path("/anything/**")
     .filters(f -> f.requestRateLimiter(c -> c.setRateLimiter(redisRateLimiter())))
     .uri("http://httpbin.org"))
     .build();
  }
}

public interface RouteDefinitionWriter {
 Mono<Void> save(Mono<RouteDefinition> route);
 Mono<Void> delete(Mono<String> routeId);
}

@Component
public class RedisRouteDefinitionRepository implements RouteDefinitionRepository {
 public static final String GW_ROUTES = "apis_gateway_routes";
 
  @Autowired
  private StringRedisTemplate redisTemplate;
  
  @Override
  public Flux<RouteDefinition> getRouteDefinitions() {
   List<RouteDefinition> routeDefinitions = new ArrayList<>();
   redisTemplate.opsForHash().values(GW_ROUTES).stream()
  .forEach(routeDefinition -> routeDefinitions.add(JSON.parseObject(routeDefinition.toString(),  RouteDefinition.class)));
   return Flux.fromIterable(routeDefinitions);
  }
  
  @Override
  public Mono<Void> save(Mono<RouteDefinition> route) {
    RouteDefinition definition = new RouteDefinition();
    definition.setId("id");
    URI uri = UriComponentsBuilder.fromHttpUrl("lb://consumer-service").build().toUri();
    definition.setUri(uri);
    PredicateDefinition predicate = new PredicateDefinition();
    predicate.setName("Path");
    Map<String, String> predicateArgs = new HashMap<>();
    predicateArgs.put("pattern", "/consumer/**");
    predicate.setArgs(predicateArgs);
    definition.setPredicates(Arrays.asList(predicate));
    FilterDefinition filter = new FilterDefinition();
    filter.setName("StripPrefix");
    Map<String, String> filterArgs = new HashMap<>();
    filterArgs.put("_genkey_0", "1");
    filter.setArgs(filterArgs);
    definition.setFilters(Arrays.asList(filter));
    redisTemplate.opsForHash().put(GW_ROUTES, "routeKey", JSON.toJSONString(definition));
    return null;
  }
  
  @Override
  public Mono<Void> delete(Mono<String> routeId) {
   return null;
  }
}

@RestController
@RequestMapping("/routes")
public class RouteController implements ApplicationEventPublisherAware {

  @Autowired
  private RedisRouteDefinitionRepository routeDefinitionWriter;
  
  private ApplicationEventPublisher publisher;

  @Override
  public void setApplicationEventPublisher(ApplicationEventPublisher publisher) {
   this.publisher = publisher;
  }
  
  @PostMapping
  public String addRoute(@RequestBody RouteDefinition definition) {
   routeDefinitionWriter.save(Mono.just(definition)).subscribe();
   this.publisher.publishEvent(new RefreshRoutesEvent(this));
   return "0";
  }
  
  @GetMapping("/{id}")
  public String delete(@PathVariable String id) {
    this.routeDefinitionWriter.delete(Mono.just(id)).subscribe();
    this.publisher.publishEvent(new RefreshRoutesEvent(this));
    return "0";
  }
}