How can I write a rule in web.config to start another node app inside a subfolder by changing the domain

Question

I have a web app running in Azure. The folder that I am deploying is made of:

-testapp
    node_modules
    index.js
    package.json
    package-lock.json
    web.config
    -testapp2
        node_modules
        index.js
        package.json
        package-lock.json

The source code in ./index.js and ./testapp2/index.js are almost the same, only the outputs are different

const express = require("express");
const app = express();


app.get("/", (_, res)=>{
    res.status(200).send("Welcome to TestApp"); // testapp2: Welcome to TestApp2 
});
app.get("/test", (_, res)=>{
    res.status(200).send("TestApp TestPath"); //testapp2: TestApp2 TestPath
});

const PORT = process.env.PORT || 1337;
app.listen(PORT, () => console.log(`Listening to http://localhost:${PORT}`));

My goal is to go to the domain example.com/ and then it starts the index.js from the main folder. When I go to example.com/testapp2 then it starts the ./testapp2/index.js and I see the welcome message from the subfolder:

"Welcome to TestApp" when I go to "/"              it works
"TestApp TestPath"   when I go to "/test"          it works
"Welcome to TestApp2" when I go to "/testapp2"      instead I get "Cannot GET /testapp2"
"TestApp2 TestPath"   when I go to "/testapp2/test" instead I get "Cannot GET /testapp2/test"

I thought this problem would be solved by changing the web.config file:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <system.webServer>
    <webSocket enabled="false" />
    <handlers>
      <add name="iisnode" path="index.js" verb="*" modules="iisnode"/>
    </handlers>
    <rewrite>
      <rules>
        <rule name="NodeInspector" patternSyntax="ECMAScript" stopProcessing="true">
          <match url="^index.js\/debug[\/]?" />
        </rule>

        <rule name="StaticContent">
          <action type="Rewrite" url="public{REQUEST_URI}"/>
        </rule>

<!-- ------------------------This is the ruled I created-------------------------- -->

        <rule name="TestApp2Content" stopProcessing="true">
          <match url="^testapp2"/>
          <conditions>
            <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="True"/>
          </conditions>
          <action type="Rewrite" url="testapp2/index.js"/>
        </rule>

<!-- ----------------------------------------------------------------------------- -->
        
        <rule name="DynamicContent">
          <conditions>
            <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="True"/>
          </conditions>
          <action type="Rewrite" url="index.js"/>
        </rule>

      </rules>
    </rewrite>
    
    <security>
      <requestFiltering>
        <hiddenSegments>
          <remove segment="bin"/>
        </hiddenSegments>
      </requestFiltering>
    </security>

    <httpErrors existingResponse="PassThrough" />
  </system.webServer>
</configuration>

But I am still getting the Cannot GET Error. I wanted to know what am I doing wrong. I am a beginner when it comes to that configuration file and the Rewrite Rules, that's why I am pretty sure that there is the error but I don't know how to write the rule properly. What am I doing wrong?

Thanks a lot for your time!

Answer 1

testapp and testapp2 should be two different applications, the best way for deploying multiple Apps on Azure WebApps is to set the Virtual applications and directories of Application Settings for your Azure Webapp.

There is a similar question in this link, you can refer to it.