IIS Outbound Rewrite Rule for srcset only rewrite once

Question

I have one problem with one outboundRule created on IIs to change text in html. The problem is inside img tag in srcset attribute when it only change last match.

I've tried this:

<outboundRules>
  <rule name="ReverseProxyOutboundRuleHTML" preCondition="ResponseIsHTML" enabled="true" patternSyntax="ECMAScript" stopProcessing="false">
    <match filterByTags="A, Area, Base, Form, Frame, Head, IFrame, Img, Input, Link, Script, CustomTags" customTags="customTags" pattern="(.*)9999.99.99.99:8080(.*)" />
    <action type="Rewrite" value="{R:1}example.com{R:2}" />
  </rule>           
  <preConditions>
    <preCondition name="ResponseIsHTML"> 
      <add input="{RESPONSE_CONTENT_TYPE}" pattern="^text/html" />
    </preCondition>
  </preConditions>
  <customTags>
    <tags name="customTags">
      <tag name="img" attribute="srcset" />
      <tag name="meta" attribute="content" />
    </tags>
  </customTags>
</outboundRules>

Seems to be correct, but my result is:

<img 
src="http://example.com/wp-content/uploads/2019/02/Mercedes_ClasseV-1024x540.png" 
srcset="http://9999.99.99.99:8080/wp-content/uploads/2019/02/Mercedes_ClasseV-1024x540.png 1024w, http://9999.99.99.99:8080/wp-content/uploads/2019/02/Mercedes_ClasseV-300x158.png 300w, http://9999.99.99.99:8080/wp-content/uploads/2019/02/Mercedes_ClasseV-768x405.png 768w, http://example.com/wp-content/uploads/2019/02/Mercedes_ClasseV.png 1100w" 
sizes="(max-width: 750px) 100vw, 750px">

Any help, to change all values in srcset attribute?

Answer 1

You could use below Rewrite rule:

 <outboundRules>
  <rule name="ReverseProxyOutboundRuleHTML" preCondition="ResponseIsHTML" enabled="true" patternSyntax="ECMAScript" stopProcessing="false">
    <match filterByTags="A, Area, Base, Form, Frame, Head, IFrame, Img, Input, Link, Script, CustomTags" customTags="customTags" pattern="(.*)9999.99.99.99:8080(.*),(.*)9999.99.99.99:8080(.*)\,(.*)9999.99.99.99:8080(.*)" />
    <action type="Rewrite" value="{R:1}example.com{R:2},{R:3}example.com{R:4},{R:5}example.com{R:6}" />
  </rule>           
  <preConditions>
    <preCondition name="ResponseIsHTML"> 
      <add input="{RESPONSE_CONTENT_TYPE}" pattern="^text/html" />
    </preCondition>
  </preConditions>
  <customTags>
    <tags name="customTags">
      <tag name="img" attribute="srcset" />
      <tag name="meta" attribute="content" />
    </tags>
  </customTags>
</outboundRules>

Regards, Jalpa.