SpringCloud微服务系列04-Alibaba架构01-Gateway-02-Predicate

Route Predicate Factories

Spring Cloud Gateway 匹配路由作为 Spring WebFlux HandlerMapping 基础结构的一部分。 Spring Cloud Gateway 包括许多内置的路由谓词工厂。所有这些谓词都匹配 HTTP 请求的不同属性。可以组合多个路由谓词工厂，并通过逻辑与进行组合。

Spring Cloud Gateway matches routes as part of the Spring WebFlux HandlerMapping infrastructure. Spring Cloud Gateway includes many built-in Route Predicate Factories. All of these predicates match on different attributes of the HTTP request. Multiple Route Predicate Factories can be combined and are combined via logical and.

After Route Predicate Factory

把RouteConfig.java注释掉

AfterRoutePredicateFactory，可配置一个时间，当请求的时间在配置时间之后，才交给 router去处理。否则则报错，不通过路由。

当请求的时间在这个配置的时间之后，请求会被路由到http://httpbin:org:80/get。:

在工程的application.yml配置如下：

server:
  port: 8711
spring:
  profiles:
    active: after_route
  application:
    name: gateway-8711

---

spring:
  profiles: after_route
  cloud:
    gateway:
      routes:
        - id: after_route
          uri: http://httpbin.org:80/get
#          当请求的时间在这个配置的时间之后，请求会被路由到http://httpbin:org:80/get。:
          predicates:
            - After=2017-01-20T17:42:47.789-07:00[America/Denver]

它实际被AfterRoutePredicateFactory这个类所处理，这个After就是指定了它的Gateway web handler类为AfterRoutePredicateFactory，同理，其他类型的predicate也遵循这个规则。

测试

进入服务http://localhost:8711/

after修改时间大于当前实际时间测试

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#          当请求的时间在这个配置的时间之后，请求会被路由到http://httpbin:org:80/get。:
          predicates:
            - After=2022-01-20T17:42:47.789-07:00[America/Denver]

再次测试

Before Route Predicate Factory

The Before Route Predicate Factory takes one parameter, a datetime. This predicate matches requests that happen before the current datetime.

和之前那个after的原理一养,只不过时间是方向

Between Route Predicate Factory

1 2	predicates: - Between=2017-01-20T17:42:47.789-07:00[America/Denver], 2017-01-21T17:42:47.789-07:00[America/Denver]

在这个时间区间内可分发路由

The Cookie Route Predicate Factory takes two parameters, the cookie name and a regular expression. This predicate matches cookies that have the given name and the value matches the regular expression.

Cookie Route Predicate Factory需要2个参数，一个时cookie名字，另一个时值，可以为正则表达式。它用于匹配请求中，带有该名称的cookie和cookie匹配正则表达式的请求。

spring:
  cloud:
    gateway:
      routes:
      - id: cookie_route
        uri: http://example.org
        predicates:
        - Cookie=chocolate, ch.p

在上面的配置中，请求带有cookie名为 name, cookie值为forezp 的请求将都会转发到uri为 http://httpbin.org:80/get的地址上。使用curl命令进行请求，在请求中带上 cookie，会返回正确的结果，否则，请求报404错误。

当cookie匹配时转发

Header Route Predicate Factory

The Header Route Predicate Factory takes two parameters, the header name and a regular expression. This predicate matches with a header that has the given name and the value matches the regular expression.

Header Route Predicate Factory需要2个参数，一个是header名，另外一个header值，该值可以是一个正则表达式。当此断言匹配了请求的header名和值时，断言通过，进入到router的规则中去。

spring:
  cloud:
    gateway:
      routes:
      - id: header_route
        uri: http://example.org
        predicates:
        - Header=X-Request-Id, \d+

在上面的配置中，当请求的Header中有X-Request-Id的header名，且header值为数字时，请求会被路由到配置的 uri. 使用curl执行以下命令:

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C:\Users\DELL>curl -H Cookie:chocolate=ch.p http://localhost:8711/
<!DOCTYPE html>
<!--STATUS OK--><html> <head><meta http-equiv=content-type content=text/html;charset=utf-8><meta http-equiv=X-UA-Compatible content=IE=Edge><meta content=always name=referrer><link rel=stylesheet type=text/css href=http://s1.bdstatic.com/r/www/cache/bdorz/baidu.min.css><title>百度一下，你就知道</title></head> <body link=#0000cc> <div id=wrapper> <div id=head> <div class=head_wrapper> <div class=s_form> <div class=s_form_wrapper> <div id=lg> <img hidefocus=true src=//www.baidu.com/img/bd_logo1.png width=270 height=129> </div> <form id=form name=f action=//www.baidu.com/s class=fm> <input type=hidden name=bdorz_come value=1> <input type=hidden name=ie value=utf-8> <input type=hidden name=f value=8> <input type=hidden name=rsv_bp value=1> <input type=hidden name=rsv_idx value=1> <input type=hidden name=tn value=baidu><span class="bg s_ipt_wr"><input id=kw name=wd class=s_ipt value maxlength=255 autocomplete=off autofocus></span><span class="bg s_btn_wr"><input type=submit id=su value=百度一下 class="bg s_btn"></span> </form> </div> </div> <div id=u1> <a href=http://news.baidu.com name=tj_trnews class=mnav>新闻</a> <a href=http://www.hao123.com name=tj_trhao123 class=mnav>hao123</a> <a href=http://map.baidu.com name=tj_trmap class=mnav>地图</a> <a href=http://v.baidu.com name=tj_trvideo class=mnav>视频</a> <a href=http://tieba.baidu.com name=tj_trtieba class=mnav>贴吧</a> <noscript> <a href=http://www.baidu.com/bdorz/login.gif?login&amp;tpl=mn&amp;u=http%3A%2F%2Fwww.baidu.com%2f%3fbdorz_come%3d1 name=tj_login class=lb>登录</a> </noscript> <script>document.write('<a href="http://www.baidu.com/bdorz/login.gif?login&tpl=mn&u='+ encodeURIComponent(window.location.href+ (window.location.search === "" ? "?" : "&")+ "bdorz_come=1")+ '" name="tj_login" class="lb">登录</a>');</script> <a href=//www.baidu.com/more/ name=tj_briicon class=bri style="display: block;">更多产品</a> </div> </div> </div> <div id=ftCon> <div id=ftConw> <p id=lh> <a href=http://home.baidu.com>关于百度</a> <a href=http://ir.baidu.com>About Baidu</a> </p> <p id=cp>&copy;2017&nbsp;Baidu&nbsp;<a href=http://www.baidu.com/duty/>使用百度前必读</a>&nbsp; <a href=http://jianyi.baidu.com/ class=cp-feedback>意见反馈</a>&nbsp;京ICP证030173号&nbsp; <img src=//www.baidu.com/img/gs.gif> </p> </div> </div> </div> </body> </html>

执行命令后，会正确的返回请求结果，结果省略。如果在请求中没有带上X-Request-Id的header名，并且值不为数字时，请求就会报404，路由没有被正确转发。

This route matches if the request has a header named X-Request-Id whos value matches the \d+ regular expression (has a value of one or more digits).

Host Route Predicate Factory

The Host Route Predicate Factory takes one parameter: the host name pattern. The pattern is an Ant style pattern with . as the separator. This predicates matches the Host header that matches the pattern.

spring:
  profiles:
    active: host_route
---
spring:
  cloud:
    gateway:
      routes:
      - id: host_route
        uri: http://httpbin.org:80/get
        predicates:
        - Host=**.jermaine.com
  profiles: host_route

在上面的配置中，请求头中含有Host为fangzhipeng.com的请求将会被路由转发转发到配置的uri。启动工程，执行以下的curl命令，请求会返回正确的请求结果：

1	curl -H 'Host:www.fangzhipeng.com' localhost:8081

输入curl -H Host:www.jerma.com http://localhost:8711 结果如下

1 2	C:\Users\DELL>curl -H Host:www.jerma.com http://localhost:8711 {"timestamp":"2021-11-04T01:39:59.438+00:00","path":"/","status":404,"error":"Not Found","message":null,"requestId":"ed01fe77-5"}

输入curl -H Host:www.jermaine.com http://localhost:8711后结果如下

C:\Users\DELL>curl -H Host:www.jermaine.com http://localhost:8711
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>httpbin.org</title>
    <link href="https://fonts.googleapis.com/css?family=Open+Sans:400,700|Source+Code+Pro:300,600|Titillium+Web:400,600,700"
        rel="stylesheet">
    <link rel="stylesheet" type="text/css" href="/flasgger_static/swagger-ui.css">
    <link rel="icon" type="image/png" href="/static/favicon.ico" sizes="64x64 32x32 16x16" />
    <style>
        html {
            box-sizing: border-box;
            overflow: -moz-scrollbars-vertical;
            overflow-y: scroll;
        }

Method Route Predicate Factory

The Method Route Predicate Factory takes one parameter: the HTTP method to match.

Method Route Predicate Factory 需要一个参数，即请求的类型。比如GET类型的请求都转发到此路由。在工程的配置文件加上以下的配置：

---
spring:
  cloud:
    gateway:
      routes:
      - id: method_route
        uri: http://httpbin.org:80/get
        predicates:
        - Method=GET
  profiles: method_route

curl localhost:8081

使用 curl命令模拟 post请求，则返回404结果。

curl -XPOST localhost:8081

Path Route Predicate Factory

The Path Route Predicate Factory takes one parameter: a Spring PathMatcher pattern.

Path Route Predicate Factory 需要一个参数: 一个spel表达式，应用匹配路径。

在工程的配置文件application.yml文件中，做以下的配置：

这个是目前所有predicates中使用最频繁的:

---
spring:
  cloud:
    gateway:
      routes:
      - id: path_route
        uri: http://httpbin.org:80/get
        predicates:
        - Path=/foo/{segment}
  profiles: path_route

Query Route Predicate Factory

The Query Route Predicate Factory takes two parameters: a required param and an optional regexp.

Query Route Predicate Factory 需要2个参数:一个参数名和一个参数值的正则表达式。在工程的配置文件application.yml做以下的配置：

---
spring:
  cloud:
    gateway:
      routes:
      - id: query_route
        uri: http://httpbin.org:80/get
        predicates:
        - Query=foo, ba.
  profiles: query_route

curl localhost:8081?foo=bar

Query Route Predicate Factory也可以只填一个参数，填一个参数时，则只匹配参数名，即请求的参数中含有配置的参数名，则命中路由。比如以下的配置中，配置了请求参数中含有参数名为foo 的参数将会被请求转发到uri为http://httpbin.org:80/get。

spring:
  cloud:
    gateway:
      routes:
      - id: query_route
        uri: http://httpbin.org:80/get
        predicates:
        - Query=foo
  profiles: query_route

RemoteAddr Route Predicate Factory

he RemoteAddr Route Predicate Factory takes a list (min size 1) of CIDR-notation (IPv4 or IPv6) strings, e.g. 192.168.0.1/16 (where 192.168.0.1 is an IP address and 16 is a subnet mask).

application.yml.

spring:
  cloud:
    gateway:
      routes:
      - id: remoteaddr_route
        uri: http://example.org
        predicates:
        - RemoteAddr=192.168.1.1/24

This route would match if the remote address of the request was, for example, 192.168.1.10.

还有很多Predicate Factory可以参考https://cloud.spring.io/spring-cloud-static/spring-cloud-gateway/2.0.0.RELEASE/single/spring-cloud-gateway.html#gateway-starter

总结如一下图片

12191355-7c74ff861a209cd9

引用资料

https://spring.io/guides/gs/gateway

https://www.fangzhipeng.com/springcloud/2018/11/06/sc-f-gateway1.html

https://github.com/alibaba/spring-cloud-alibaba/blob/master/README-zh.md

https://www.fangzhipeng.com/springcloud/2018/12/21/sc-f-gatway1.html

https://www.fangzhipeng.com/springcloud/2018/12/05/sc-f-gateway2.html

https://www.fangzhipeng.com/springcloud/2018/12/21/sc-f-gatway3.html

springcloud之gateway路由熔断

https://blog.csdn.net/guaniuqaq/article/details/88256226

SpringCloud微服务系列04-Alibaba架构01-Gateway-02-Predicate