spring cloud gateway的stripPrefix配置

序

本文主要研究下spring cloud gateway的stripPrefix配置

使用zuul的配置

zuul:
  routes:
    demo:
      sensitiveHeaders: Access-Control-Allow-Origin,Access-Control-Allow-Methods    
      path: /demo/**
      stripPrefix: true
      url: http://demo.com.cn/

这里的stripPrefix默认为true，也就是所有/demo/xxxx的请求转发给http://demo.com.cn/xxxx ,去除掉demo前缀

使用spring cloud gateway的配置

spring:
  cloud:
    gateway:
      default-filters:
      - AddResponseHeader=X-Response-Default-Foo, Default-Bar
      routes:
      - id: demo
        uri: http://demo.com.cn:80
        order: 8999 ## 越小越优先
        predicates: 
        - Path=/demo/**
        filters:
        - RewritePath=/demo/(?<segment>.*), /$\{segment}

spring cloud gateway貌似没有现成的stripPrefix的配置，不过可以通过rewritepath来实现

spring-cloud-gateway-core-2.0.0.M6-sources.jar!/org/springframework/cloud/gateway/filter/factory/RewritePathGatewayFilterFactory.java

public class RewritePathGatewayFilterFactory implements GatewayFilterFactory {

    public static final String REGEXP_KEY = "regexp";
    public static final String REPLACEMENT_KEY = "replacement";

    @Override
    public List<String> argNames() {
        return Arrays.asList(REGEXP_KEY, REPLACEMENT_KEY);
    }

    @Override
    public GatewayFilter apply(Tuple args) {
        final String regex = args.getString(REGEXP_KEY);
        String replacement = args.getString(REPLACEMENT_KEY).replace("$\\", "$");
        return apply(regex, replacement);
    }

    public GatewayFilter apply(String regex, String replacement) {
        return (exchange, chain) -> {
            ServerHttpRequest req = exchange.getRequest();
            addOriginalRequestUrl(exchange, req.getURI());
            String path = req.getURI().getPath();
            String newPath = path.replaceAll(regex, replacement);

            ServerHttpRequest request = mutate(req)
                    .path(newPath)
                    .build();

            exchange.getAttributes().put(GATEWAY_REQUEST_URL_ATTR, request.getURI());

            return chain.filter(exchange.mutate().request(request).build());
        };
    }
}

主要是这段String newPath = path.replaceAll(regex, replacement)，这里相当于regex是/demo/(?<segment>.*)，replacement是/${segment}

小结

spring cloud gateway利用RewritePath可以实现原来的zuul的stripPrefix的效果，而且功能更强大。

doc

• rewritepath_gatewayfilter_factory