Azure Webapp : What is the correct web.config in this case?

Question

We are currently having some troubling in deploying a Node.js application on a Windows WebApp and we suspect that the problem is in the web.config file.

Here is Project Directory Structure:

We are using the default web.config with a few changes: The application file is app.js and the public folder is dist/

<?xml version="1.0" encoding="utf-8"?>
<!--
     This configuration file is required if iisnode is used to run node processes behind
     IIS or IIS Express.  For more information, visit:

     https://github.com/tjanczuk/iisnode/blob/master/src/samples/configuration/web.config
-->

<configuration>
  <system.webServer>
    <!-- Visit http://blogs.msdn.com/b/windowsazure/archive/2013/11/14/introduction-to-websockets-on-windows-azure-web-sites.aspx for more information on WebSocket support -->
    <webSocket enabled="false" />
    <handlers>
      <!-- Indicates that the server.js file is a node.js site to be handled by the iisnode module -->
      <add name="iisnode" path="app.js" verb="*" modules="iisnode"/>
    </handlers>
    <rewrite>
      <rules>
        <!-- Do not interfere with requests for node-inspector debugging -->
        <rule name="NodeInspector" patternSyntax="ECMAScript" stopProcessing="true">
          <match url="^app.js\/debug[\/]?" />
        </rule>

        <!-- First we consider whether the incoming URL matches a physical file in the /public folder -->
        <rule name="StaticContent">
          <action type="Rewrite" url="dist{REQUEST_URI}"/>
        </rule>

        <!-- All other URLs are mapped to the node.js site entry point -->
        <rule name="DynamicContent">
          <conditions>
            <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="True"/>
          </conditions>
          <action type="Rewrite" url="app.js"/>
        </rule>
      </rules>
    </rewrite>
    
    <!-- 'bin' directory has no special meaning in node.js and apps can be placed in it -->
    <security>
      <requestFiltering>
        <hiddenSegments>
          <remove segment="bin"/>
        </hiddenSegments>
      </requestFiltering>
    </security>

    <!-- Make sure error responses are left untouched -->
    <httpErrors existingResponse="PassThrough" />

    <!--
      You can control how Node is hosted within IIS using the following options:
        * watchedFiles: semi-colon separated list of files that will be watched for changes to restart the server
        * node_env: will be propagated to node as NODE_ENV environment variable
        * debuggingEnabled - controls whether the built-in debugger is enabled

      See https://github.com/tjanczuk/iisnode/blob/master/src/samples/configuration/web.config for a full list of options
    -->
    <!--<iisnode watchedFiles="web.config;*.js"/>-->
  </system.webServer>
</configuration>

Currently, the IIS Rewrite module is adding dist/ to the URL, like so: http://xxxxxxx.azurewebsites.net/dist/

And we have an iisnode error message:

HRESULT: 0x2

HTTP status: 500

HTTP subStatus: 1001

HTTP reason: Internal Server Error

I tried checking the Failed Request Tracing logs but no failed request was logged.

Could someone tell me what is happening in my case ?

---

EDIT:

I decided to start back from scratch and created a new Web app.

I built the node.js app with the kudu console and (using the same web.config) the server now fetches correctly the index.html file in dist/.

So far so good, and we correctly land on the login page.

The problem now is that iisnode fails to process the POST request with the user credentials.

As Julien suggested, I tried changing the virtual directory of the app and had different errors:

1st case:

Virtual directory: /
Path: site\wwwroot
Error: The same iisnode error as the above

2nd case:

Virtual directory: /
Path: site\wwwroot\dist
Error: The resource you are looking for has been removed, had its name changed, or is temporarily unavailable.

Any thoughts on that ?
Thank you

Answer 1

Depending on how you are pushing your App to web app, you can try to:

• Use the PROJECT environment variable to specify that your app is in the dist folder, as explained here.
• Define a virtual directory in the web app settings to specify that the root folder of your application is site\wwwroot\dist. You can find a JSON example of configuration here or use the Application Settings blade in the Azure portal.

Hope this helps

Julien

Answer 2

Actually, your web.config is correct.

You can try replacing the content of app.js with the following minimal Node.js app to see if it works.

var http = require('http');

var server = http.createServer(function(req, res) {
  res.writeHead(200);
  res.end('Hello Azure');
});
server.listen(process.env.PORT);

Important: use process.env.PORT as the port in your script when it runs on Azure Web Service.