rewrite rule for folder to different host - iis

Question

There are 2 applications running on local network:
host headers:
http://ui.local, http://api.local
On another server, a website is already setup for url rewriting. Host header of the site is http://externalui.mydomain.com
Here is web.config contents:
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<system.webServer>
<rewrite>
<rules>
<rule name="ReverseProxyInboundRule1" stopProcessing="true">
<match url="(.*)" />
<action type="Rewrite" url="http://ui.local/{R:1}" />
</rule>
</rules>
</rewrite>
<httpProtocol>
<customHeaders>
<add name="Access-Control-Allow-Origin" value="*" />
<add name="Access-Control-Allow-Methods" value="GET,PUT,POST,DELETE,OPTIONS" />
<add name="Access-Control-Allow-Headers" value="Content-Type" />
</customHeaders>
</httpProtocol>
</system.webServer>
</configuration>
This url rewriting rule is running without a problem and rewrites all URLs made to http://externalui.mydomain.com to go to http://ui.local
However i want to write another rule so requests made to http://externalui.mydomain.com/api/.... will be forwarded to http://api.local/api/... instead.
How to write a rule for this condition?

Answer 1

You could use the below rule:
<rule name="redirect api" stopProcessing="true">
<match url="api/(.*)" />
<conditions logicalGrouping="MatchAll" trackAllCaptures="false" />
<action type="Redirect" url="http://api.local/api/{R:1}" />
</rule>
<rule name="all redirect" stopProcessing="true">
<match url="(.*)" />
<conditions logicalGrouping="MatchAll" trackAllCaptures="false">
</conditions>
<action type="Redirect" url="http://ui.local/{R:1}" />
</rule>
Note: make sure the API rule should be the first rule.