How do I make Openshift to use Express 4, instead of its installed Express 3? - node.js

Question

I developed my Nodejs Express app locally using Express 4 and it works as expected on my computer. I then git the whole app up to Openshift. When I try to run it Openshift returns"503 Service Unavailable". If I ssh into my base Node cartridge and do "express -V" it returns version 3.2.5. I get the same version 3.2.5 if I go into my app folder at app-root/repo and run "express -V".
So clearly my Express 4 which was included in the git upload in my app's node_modules is not being used. What is the solution to use Express 4 as required by my app?
Ideas are- remove Openshift's version of Express 3, force Openshift to use my Express 4 in my app area, upgrade Openshift's Express 3 to Express 4. I cannot figure out how to do any of those and I have researched this.

Answer 1

Here's how to troubleshoot:
ssh into your cartridge
cd into the app-root/repo directory
run grep version ./node_modules/express/package.json
you should see a version based on your package.json dependency
verify your package.json has a scripts section containing a start command that just runs your app with something like node ./server.js (server.js being whatever file you coded your main app start script in). You don't need the express command line program to launch an express server. It's for setting up new project boilerplate and other ancillary tasks.
To see the version of express running within your app, you can add this code to your server.js (or equivalent) file: console.log(require("express/package").version);

Answer 2

Look at this project to know how to integrate openshift with express4
Its a simple example .
https://github.com/master-atul/openshift-express4

Answer 3

try this
rhc ssh
cd app-root/repo
npm start
also edit the ./bin/www
var port = normalizePort(process.env.OPENSHIFT_NODEJS_PORT || '8080');
var ip = process.env.OPENSHIFT_NODEJS_IP;
if (typeof ip === "undefined") {
// Log errors on OpenShift but continue w/ 127.0.0.1 - this
// allows us to run/test the app locally.
console.warn('No OPENSHIFT_NODEJS_IP var, using 127.0.0.1');
ip = "127.0.0.1";
};
//app.set('ip', port);
app.set('port', port);
var server = http.createServer(app);
server.listen(port, ip);
server.on('error', onError);
server.on('listening', onListening);

Answer 4

you can follow step:
copy all content bin/www and replace all content in file server.js:
Change some content at server.js:
from
`var port = normalizePort(process.env.PORT || '3000');`
to
var port = normalizePort(process.env.OPENSHIFT_NODEJS_PORT || '3000');
Add line:
var ip = process.env.OPENSHIFT_NODEJS_IP || '127.0.0.1';
from
server.listen(port);
to
server.listen(port, ip);
Add more to package.json
from
"scripts": {
"start": "node bin/www"
},
to
"scripts": {
"start": "node server.js"
},
Add line:
"main": "server.js",
Use npm install --save module-name for npm install
create file .gitignore with content:
node_modules
on local run node server.js to start server with address localhost:3000
upload to openshift:
git add .
git commit -m "First update new server version"
git push
Browser: domain-appname.rhcloud.com