如何使用 Spring Cloud Gateway 自定义过滤器过滤每个请求？

Question

这是我第一次实现 Spring Cloud Gateway。

我需要过滤每个请求并在某些路径上应用过滤器验证。在Baeldung Custom Filters tutorial 之后，我做了一个简单的应用程序来过滤请求。

应用程序必须发布/actuator/health 之类的路径，并验证后端服务的特定路径。到目前为止，我已经实现了GlobalFilter 和GatewayFilterFactory。每个请求都会调用全局过滤器，但在应用程序启动时只调用一次 GatewayFilter，这样我就无法为每个请求创建身份验证逻辑。 auth 逻辑是关于一个特定的头字段。所以，我的具体问题是：

1. 如何使用特定路径验证每个请求？
2. 如何拒绝请求并发送错误信息？

全局过滤器

@Component
public class LoggingGlobalPreFilter implements GlobalFilter {

    final Logger LOGGER = LoggerFactory.getLogger(LoggingGlobalPreFilter.class);

    @Override
    public Mono<Void> filter(
            ServerWebExchange exchange,
            GatewayFilterChain chain) {
        LOGGER.info("Global Pre Filter executed");
        return chain.filter(exchange);
    }

}

网关过滤器

@Component
public class LoggingGatewayFilterFactory extends
        AbstractGatewayFilterFactory<LoggingGatewayFilterFactory.Config> {

    final Logger LOGGER =
            LoggerFactory.getLogger(LoggingGatewayFilterFactory.class);

    public LoggingGatewayFilterFactory() {
        super(Config.class);
    }

    private Mono<Void> onError(ServerWebExchange exchange, String err, HttpStatus httpStatus)  {
        ServerHttpResponse response = exchange.getResponse();
        response.setStatusCode(httpStatus);
        return response.setComplete();
    }

    private boolean isAuthorizationValid(String authorizationHeader) {
        boolean isValid = true;
        return authorizationHeader.equals("x-header");
    }

    @Override
    public GatewayFilter apply(Config config) {
        LOGGER.info("M=apply, Msg=Applying Gateway Filter....");
        return ((exchange, chain) -> {
            LOGGER.info("M=apply, Msg=Applying Gateway Filter...."); // APARENTELLY NEVER ENTER HERE.
            ServerHttpRequest request = exchange.getRequest();

            if (!request.getHeaders().containsKey(TsApiGatewayConstants.HEADER_APIKEY)) {
                return this.onError(exchange, TsApiGatewayConstants.MESSAGE_API_KEY_MISSING, HttpStatus.UNAUTHORIZED);
            }

            String apiKey = request.getHeaders().get(TsApiGatewayConstants.HEADER_APIKEY).get(0);
            String userAgent = request.getHeaders().get(TsApiGatewayConstants.HEADER_USER_AGENT).get(0);

            if (!this.isAuthorizationValid(userAgent)) {
                return this.onError(exchange, TsApiGatewayConstants.MESSAGE_API_KEY_INVALID, HttpStatus.UNAUTHORIZED);
            }

            return chain.filter(exchange);
        });
    }

    public static class Config {
        private String baseMessage;
        private boolean preLogger;
        private boolean postLogger;

        public Config(String baseMessage, boolean preLogger, boolean postLogger) {
            this.baseMessage = baseMessage;
            this.preLogger = preLogger;
            this.postLogger = postLogger;
        }

        public String getBaseMessage() {
            return baseMessage;
        }

        public void setBaseMessage(String baseMessage) {
            this.baseMessage = baseMessage;
        }

        public boolean isPreLogger() {
            return preLogger;
        }

        public void setPreLogger(boolean preLogger) {
            this.preLogger = preLogger;
        }

        public boolean isPostLogger() {
            return postLogger;
        }

        public void setPostLogger(boolean postLogger) {
            this.postLogger = postLogger;
        }
    }
}

application.yml

  cloud:
    gateway:
      routes:
      - id: service_route
        uri: https://backend-url:443
        predicates:
          - Path=/api
        filters:
         - Logging

过滤器的示例路径：https://backend-url:443/api/service1

Answer 1

我找到了解决它的方法。我使用了一个 RouteConfiguration 组件来设置路由和一个 GatewayFilter 类。在 RouteConfiguration 的 Bean 上，我已将特定过滤器设置为路由路径。就我而言，我使用了过滤器进行身份验证。

网关过滤器

@RefreshScope
@Component
public class AuthenticationFilter implements GatewayFilter {

    final Logger LOGGER = LoggerFactory.getLogger(AuthenticationFilter.class);

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        ServerHttpRequest request = exchange.getRequest();

// Make your business logic, this is a simple sample.


        if (!request.getHeaders().containsKey("x-api-key")) {
            return this.onError(exchange,"api-key missing",HttpStatus.FORBIDDEN);
        }

        return chain.filter(exchange); // Forward to route
    }

    private Mono<Void> onError(ServerWebExchange exchange, String err, HttpStatus httpStatus)  {
        ServerHttpResponse response = exchange.getResponse();
        response.setStatusCode(httpStatus);
        return response.setComplete();
    }

路线配置

@RefreshScope
@Configuration
public class RouteConfiguration {

    @Value("${routes.api}")
    private String apiHost;

    @Autowired
    AuthenticationFilter authenticationFilter;

    @Bean
    public RouteLocator apiRoutes(RouteLocatorBuilder builder) {
        return builder.routes()
                .route("CHOICE A ROUTE ID",p -> p
                        .path("/api/**")
                        .filters(f -> f
                                .filter(authenticationFilter) // You can add more filters here.
                                .stripPrefix(1))
                        .uri(apiHost))
                .build();
    }

}

Answer 2

如果你想验证每个请求，你应该实现 Ordered 接口和 并返回 -2； 例如：

     @Component
public class WrapperResponseGlobalFilter implements GlobalFilter, Ordered {
    @Override
    public int getOrder() {
        // -1 is response write filter, must be called before that
        return -2;
    }
}

拒绝请求并发送错误消息 你可以看到这个 .use MonoUtil.buildServerResponse 方法。

MonoUtil