Spring Cloud Gateway 动态路由

Posted 2023-02-26

【中文标题】Spring Cloud Gateway 动态路由

【英文标题】：Spring Cloud Gateway Dynamic Routing

【发布时间】：2019-03-31 13:02:23

【问题描述】：

对 Spring Cloud Gateway 来说真的很新——但它“似乎”很容易。我真的在努力解决一个问题。我的要求是为路径添加前缀，检查标头变量，根据该变量查找 URI，然后再进行检查。

问题是 uri 始终是下面的 DEFAULT_IMPLEMENTION，即使我在 idResolvingGatewayFilter 中更改了它。我怎样才能做到这一点？可以随时添加新的 id - 这就是“动态”部分。所以在网关过滤器中，我正在读取标题并查找 uri（我正在查看的数据源可以随时更新）。但是下面的代码似乎覆盖了我在过滤器中分配的任何内容 - 如果不提​​供 URI，您将无法执行此操作。例如：

标头 ID=123 uri=http://www.somedestination.com/something/services/v1.0

header-id=999 uri=http://www.anotherdestination.com/something/services/v1.0

  @Bean
  public RouteLocator rosterRouteLocator( RouteLocatorBuilder builder )
  
    log.info( "Establishing Gateway Routes" );
    return builder.routes()
        .route( r -> r.path( "/**" ).filters( f -> f.prefixPath( "/something/services/v1.0" ).filter( idResolvingGatewayFilter() ) )
            .uri( resolver.buildDestinationEndpoint( IdUrlResolver.DEFAULT_IMPLEMENTATION ) ) )
        .build();
  

在 idResolvingGatewatFilter 中，我正在进行更改（日志语句看起来很正确......它只是不去那里！

public Mono<Void> filter( ServerWebExchange exchange, GatewayFilterChain chain )
  
    try
    
      URI newUri = buildURI( exchange );
      ServerHttpRequest request = exchange.getRequest().mutate().uri( newUri ).build();
      exchange = exchange.mutate().request( request ).build();
      log.debug( "Modified URI: " + exchange.getRequest().getURI() );

【参考方案1】：

@SpringBootApplication
public class SpringCloudGatewayApplication 

    @Autowired
    private CustomerFilter filter;

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

    @Bean
    public RouteLocator myRoutes(RouteLocatorBuilder builder) 

        return builder.routes().route(p -> p.path("/**").filters(f -> f.filter(filter)).uri("no://op")).build();
    


class CustomerFilter implements GatewayFilter, Ordered 

    @Override
    public int getOrder() 
        return RouteToRequestUrlFilter.ROUTE_TO_URL_FILTER_ORDER + 1;
    

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) 
        String newUrl = null;

        if (exchange.getRequest().getHeaders().getHost().toString().equals("localhost:8080")) 
            newUrl = "http://ip1/path1";
         else 
            newUrl = "http://ip2/path2";
        

        exchange.getAttributes().put(ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR, new URI(newUrl));
        return chain.filter(exchange);