IIS Rewrite ARR配置子站点反向代理后根URL无法指向旧应用咨询

你当前的配置存在两个核心问题导致根路径代理失效：

1. 根路径访问触发目录判断逻辑
   访问www.mysite.com/时，IIS会将请求识别为站点根目录，匹配Legacy规则中的IsDirectory条件后返回true，由于你设置了negate="true"（排除存在的目录），整个规则条件不满足，因此不会执行根路径的代理转发。
2. 规则顺序不合理
   HTTP转HTTPS规则放在/app1、/app2代理规则之后，导致HTTP访问子站点时不会跳转到HTTPS，直接走HTTP协议转发到后端，不符合全站HTTPS的配置预期。

调整规则顺序，同时拆分Legacy代理规则单独处理根路径，修正后的完整配置如下：

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <rewrite>
            <rules>
                <!-- 全站HTTP转HTTPS放到最前面 -->
                <rule name="Redirect HTTP to HTTPS" stopProcessing="true">
                    <match url="(.*)" />
                    <conditions>
                        <add input="{HTTPS}" pattern="off" />
                    </conditions>
                    <action type="Redirect" url="https://{HTTP_HOST}/{R:1}" redirectType="Permanent" />
                </rule>
                <rule name="Reverse Proxy to App1" stopProcessing="true">
                    <match url="^app1/?(.*)" /> <!-- 优化正则，兼容不带斜杠的/app1访问 -->
                    <conditions logicalGrouping="MatchAll">
                      <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
                      <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
                    </conditions>
                    <action type="Rewrite" url="http://pc1.local/{R:1}" />
                </rule>
                <rule name="Reverse Proxy to App2" stopProcessing="true">
                    <match url="^app2/?(.*)" /> <!-- 优化正则，兼容不带斜杠的/app2访问 -->
                    <conditions logicalGrouping="MatchAll">
                      <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
                      <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
                    </conditions>
                    <action type="Rewrite" url="http://pc2.local/{R:1}" />
                </rule>
                <!-- 单独处理根路径代理，不校验文件/目录存在性 -->
                <rule name="Reverse Proxy to Legacy Root" stopProcessing="true">
                    <match url="^$" />
                    <action type="Rewrite" url="http://legacypc.local/" />
                </rule>
                <!-- 处理旧应用非根路径的其他请求 -->
                <rule name="Reverse Proxy to Legacy App" stopProcessing="true">
                    <match url="(.*)" />
                    <conditions logicalGrouping="MatchAll">
                      <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
                      <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
                    </conditions>
                    <action type="Rewrite" url="http://legacypc.local/{R:1}" />
                </rule>
            </rules>
            <outboundRules>                
                <rule name="Add STS headers to HTTPS response">
                    <match serverVariable="RESPONSE_Strict_Transport_Security" pattern=".*"/>
                    <conditions>
                        <add input="{HTTPS}" pattern="on"/>
                    </conditions>
                    <action type="Rewrite" value="max-age=31536000"/>
                </rule>
                <rule name="Ensure secure Cookies" preCondition="Missing secure cookie">
                    <match serverVariable="RESPONSE_Set_Cookie" pattern=".*" negate="false" />
                    <action type="Rewrite" value="{R:0}; secure" />
                </rule>
                <preConditions>
                    <preCondition name="Missing secure cookie">
                        <add input="{RESPONSE_Set_Cookie}" pattern="." />
                        <add input="{RESPONSE_Set_Cookie}" pattern="; secure" negate="true" />
                    </preCondition>
                </preConditions>
            </outboundRules>
        </rewrite>
        <defaultDocument enabled="false" />
    </system.webServer>
</configuration>

配置更新后需要清空浏览器缓存（301重定向是永久缓存的），再重新测试访问即可。

内容的提问来源于stack exchange，提问作者Richard Plaatjes