How to setup reverse proxy with express-cloudant on openshift hosted nodejs

Question

I ran into the Cross domain policy issue when i wanted to access my couchdb from my website on another host. So I setup a nodejs on openshift to create a reverse proxy with express-cloudant. After modifing the nodejs app example from openshift, I'm currently able to reach the index and readme file which is set via app.get

self.app.get('/', routesDir.index);
self.app.get('/readme', require('./routes/readme'));

But when it comes to the proxy, which should redirect to my cloudant couchdb, I end up with Error 503. This is, how i set up the proxy (from the app.js example in https://github.com/cloudant-labs/express-cloudant)

proxy = require('./routes/proxy'),
http = require('http'),
path = require('path'),
proxy_url = "https://" +
        process.env.USERNAME +
        ".cloudant.com",
admin_url = "https://" +
        process.env.USERNAME +
        ":" +
        process.env.PASSWORD +
        "@" +
        process.env.USERNAME +
        ".cloudant.com";    self.app = express();

    //Cloudant
    self.app.set('port', process.env.PORT || 3000);
    console.log('Port: ' + self.app.get('port'));
    self.app.set('views', __dirname + '/views');
    self.app.set('view engine', 'jade');
    self.app.use(express.favicon());
    self.app.use(express.logger('dev'));
 // all requests to /proxy* get forwarded to Cloudant through the proxy
    self.app.use(proxy('proxy', proxy_url));
    self.app.use(express.bodyParser());
    self.app.use(express.methodOverride());
    self.app.use(self.app.router);
    self.app.use(express.static(path.join(__dirname, 'public')));

    // development only
    if ('development' == self.app.get('env')) {
      self.app.use(express.errorHandler());
    }

    self.app.get('/', routesDir.index);
    self.app.get('/readme', require('./routes/readme'));
    require('./routes/api')(self.app, 'api', admin_url);

The content of the proxy.js (which i left unmodified):

module.exports = function(prefix, proxy_url){
  return function(req, res, next){
    var proxy_path = req.path.match(RegExp("^\\/" + prefix + "(.*)$"));
    console.log('Proxy path: ' + proxy_path);
    if(proxy_path){
      var db_url = proxy_url + proxy_path[1];
      req.pipe(request({
        uri: db_url,
        method: req.method,
        qs: req.query
      })).pipe(res);
    } else {
      next();
    }
  };
};

And my request looks as follows:

curl -vX POST http://myproxy-myappws.rhcloud.com/proxy/_session -H 'application/x-www-form-urlencoded' -d 'name=myuser&password=mypassword'

This ends up with Error 503

When i try the same request with:

curl -vX POST https://me.cloudant.com/_session -H 'application/x-www-form-urlencoded' -d 'name=myuser&password=mypassword'

it works perfectly.

I'm new to nodejs and express-cloudant, so maybe I'm missing a very essential thing. Any infos, directions, hints please?

Answer 1

If you are running that script on openshift, you need to listen on port 8080 for it to be externally accessible, or listen on OPENSHIFT_NODEJS_PORT.