node web app in azure is blank - node.js

Question

I'm new to node and express but I'm having an issue when I host my node web app in windows azure which by the way works completely fine on localhost. I just get a blank white screen.
this is my:
server.js
var root = require('root');
var github = require('github-auth');
var express = require('express');
var path = require('path');
// var app = root();
var app = express();
var gh = github('clientid', 'clientsecret, {
organization: 'my-org',
team: 'my-team',
autologin: true // This automatically redirects you to github to login
});
app.get('/login', gh.login);
app.use(express.static(__dirname + '/'));
app.all('*', gh.authenticate);
app.all('*', function(req, res, next) {
if (!req.github) return res.sendFile(__dirname + '/login.html');
if (!req.github.authenticated) res.sendFile(path.join(__dirname+'/kickout.html'));
next();
});
app.get('/main',function(req,res){
res.sendFile(path.join(__dirname+'/main.html'));
});
app.get('/about',function(req,res){
res.sendFile('/kickout.html');
});
app.listen(3000);
console.log("Running at Port 3000");

Answer 1

Node.js application running on Azure Web Apps Service, is hosted on IIS handled mapping via IISNode, which gives a Named Pipe to receive the incoming requests, not a TCP port like you would use when running locally.
This Named Pipe has been defined as the port in Node.js runtime on Azure Web Apps. You can define the port in your app link: process.env.PORT || 3000, with which your app can run on Azure or locally.
And you may check whether there is a file web.config in your root directory, which is the configurations of IIS of your application. It should have the similar content:
<configuration>
<system.webServer>
<handlers>
<!-- indicates that the app.js file is a node.js application to be handled by the iisnode module -->
<add name="iisnode" path="server.js" verb="*" modules="iisnode"/>
</handlers>
<rewrite>
<rules>
<!-- Don't interfere with requests for node-inspector debugging -->
<rule name="NodeInspector" patternSyntax="ECMAScript" stopProcessing="true">
<match url="^server.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="public{REQUEST_URI}"/>
</rule>
<!-- All other URLs are mapped to the Node.js application entry point -->
<rule name="DynamicContent">
<conditions>
<add input="{REQUEST_FILENAME}" matchType="IsFile" negate="True"/>
</conditions>
<action type="Rewrite" url="server.js"/>
</rule>
</rules>
</rewrite>
<!-- You can control how Node is hosted within IIS using the following options -->
<!--<iisnode
node_env="%node_env%"
nodeProcessCommandLine=""%programfiles%\nodejs\node.exe""
nodeProcessCountPerApplication="1"
maxConcurrentRequestsPerProcess="1024"
maxNamedPipeConnectionRetry="3"
namedPipeConnectionRetryDelay="2000"
maxNamedPipeConnectionPoolSize="512"
maxNamedPipePooledConnectionAge="30000"
asyncCompletionThreadCount="0"
initialRequestBufferSize="4096"
maxRequestBufferSize="65536"
watchedFiles="*.js"
uncFileChangesPollingInterval="5000"
gracefulShutdownTimeout="60000"
loggingEnabled="true"
logDirectoryNameSuffix="logs"
debuggingEnabled="true"
debuggerPortRange="5058-6058"
debuggerPathSegment="debug"
maxLogFileSizeInKB="128"
appendToExistingLog="false"
logFileFlushInterval="5000"
devErrorsEnabled="true"
flushResponse="false"
enableXFF="false"
promoteServerVars=""
/>-->
<iisnode watchedFiles="*.js;node_modules\*;routes\*.js;views\*.jade"/>
</system.webServer>
</configuration>

Answer 2

When hosting Node.js apps via Azure Web Apps, you need to modify your port initialization as shown in the following simplified sample:
var http = require('http'),
port = process.env.PORT || 1337;
http.createServer(function(req, res) {
res.writeHead(200, { 'Content-Type': 'text/plain' });
res.end('Hello World\n');
}).listen(port);
When running locally, the literal port will be used (e.g. 1337 above), but when running in Azure a port will be assigned to process.env.port by the hosting platform and that will be used. You can find a complete walkthrough on deploying a Node.js app here. When running in a WebApp, a technology called IIS Node is used to run your Node app. More details on that can be found here.