how to get your existing node.js apps working on azure if you use don't server.js in the root

azurify.md

let's assume that package.json looks like this

{
  "name": "booyaalolwut",
  "version": "6.6.6",
  "description": "witty description here",
  "scripts": {
    "start": "node express/index.js"
},

your existing app starts in express/index.js

<?xml version="1.0" encoding="utf-8"?>
<configuration>
    <system.webServer>
      <handlers>
        <add name="iisnode" path="express/index.js" verb="*" modules="iisnode"/> <!-- change path here-->
     </handlers>
      <rewrite>
           <rules>
                <rule name="StaticContent">
                     <action type="Rewrite" url="public{REQUEST_URI}"/>
                   </rule>
                   <rule name="DynamicContent">
                     <conditions>
                          <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="True"/>
                     </conditions>
                    <match url="/*" /> <!-- not sure why this is missing from stock web.config on azure -->
                    <action type="Rewrite" url="express/index.js" /> <!-- change path to script -->
                </rule>
           </rules>
      </rewrite>
   </system.webServer>
 </configuration>