app.js

var express = require('express'),
    app     = express();

var port = process.env.PORT || process.env.OPENSHIFT_NODEJS_PORT || 8080,
    ip   = process.env.IP   || process.env.OPENSHIFT_NODEJS_IP || '0.0.0.0';

var route = express.Router();

// global var to track app health
var healthy = true;

app.use('/', route);

// A route that says hello
route.get('/', function(req, res) {
    res.send('Hello! This is the index page for the app.\n');
});

// A route that returns readiness status
// simulates readiness 30 seconds after start up
route.get('/ready', function(req, res) {
      var now = Math.floor(Date.now() / 1000);
      var lapsed = now - started;
      if (lapsed > 30) {
        console.log('ping /ready => pong [ready]');
        res.send('Ready for service requests...\n');
      }
      else {
	console.log('ping /ready => pong [notready]');
	res.status(503);
        res.send('Error! Service not ready for requests...\n');
      }
});

// A route that returns health status
route.get('/healthz', function(req, res) {
    if (healthy) {
      console.log('ping /healthz => pong [healthy]');
      res.send('OK\n');
    }
    else {
      console.log('ping /healthz => pong [unhealthy]');
      res.status(503);
      res.send('Error!. App not healthy!\n');
    }
});

// This route handles switching the state of the app
route.route('/flip').get(function(req, res) {

        var flag = req.query.op;
        if (flag == "kill") {
	  console.log('Received kill request. Changing app state to unhealthy...');
	  healthy = false;
	  res.send('Switched app state to unhealthy...\n');
	}
	else if (flag == "awaken") {
	  console.log('Received awaken request. Changing app state to healthy...');
	  healthy = true;
	  res.send('Switched app state to healthy...\n');
	}
	else {
	  res.send('Error! unknown flag...\n');
	}
    });

app.listen(port, ip);
console.log('nodejs server running on http://%s:%s', ip, port);
var started = Math.floor(Date.now() / 1000);

module.exports = app;