server.js

var express = require("express");
var app = express();
var cfenv = require("cfenv");

require("cf-deployment-tracker-client").track();

var mydb;

app.get("/addName", function (request, response) {
  var userName = request.query.user_name;
  if(!mydb) {
    console.log("No database.");
    response.send("Hello " + userName + "!");
    return;
  }
  // insert the username as a document
  mydb.insert({ "userName" : userName }, function(err, body, header) {
    if (err) {
      return console.log('[mydb.insert] ', err.message);
    }
    response.send("Hello " + userName + "! I added you to the database.");
  });
});

app.get("/getNames", function (request, response) {
  var names = [];
  if(!mydb) {
    response.json(names);
    return;
  }

  mydb.list({ include_docs: true }, function(err, body) {
    if (!err) {
      body.rows.forEach(function(row) {
        if(row.doc.userName)
          names.push(row.doc.userName);
      });
      response.json(names);
    }
  });
});


// load local VCAP configuration  and service credentials
var vcapLocal;
try {
  vcapLocal = require('./vcap-local.json');
  console.log("Loaded local VCAP", vcapLocal);
} catch (e) { }

const appEnvOpts = vcapLocal ? { vcap: vcapLocal} : {}

const appEnv = cfenv.getAppEnv(appEnvOpts);

if (appEnv.services['cloudantNoSQLDB']) {
  // Load the Cloudant library.
  var Cloudant = require('cloudant');

  // Initialize database with credentials
  var cloudant = Cloudant(appEnv.services['cloudantNoSQLDB'][0].credentials);

  // Create a new "mydb" database.
  cloudant.db.create('mydb', function(err, data) {
    if(err) //If database already exists
      console.log("err creating db. It might already exist.");
      //console.log(err);
    else
      console.log("Created database.");
  });

  // Specify the database we are going to use (mydb)...
  mydb = cloudant.db.use('mydb');
}

//serve static file (index.html, images, css)
app.use(express.static(__dirname + '/views'));

var port = process.env.PORT || 3000
app.listen(port, function() {
    console.log("To view your app, open this link in your browser: http://localhost:" + port);
});