Getting started with Node.js and Mongodb

Here is a post in which I try to get my arms around Node.js & MongoDB. This is first encounter with Web programming. There is a veritable universe of frameworks, languages, libraries and modules out there.

There are a gazillion blogs already on this topic so here is one more. When I came across Node.js recently,  I have been  impressed mightily with its ability to quickly cook up Webservers, TCP based server side programming and the like with really brief code. Another alluring fact was that it is based on Javascript which itself smacks of plain C, added to its charm. The experience with Node.js is difficult for a beginner. Also I must add that the Node.js’es callback functions takes a bit of getting used and I have had my share of pain with it.

MongoDB is an open-source document database, and one of the  leading NoSQL databases out there.

First things first – Install Node.js from Nodejs.org. Next install MongoDB for your OS and machine type. You will also need to install the mongodb module for use with Node.js. You can this by opening a command prompt and typing

npm install mongodb -g

This will allow you to access the mongodb module for use within your program. Now you should be good to go and create some basic code to manipulate MongoDB through Node.js.  This code is based on the commands from the following MongoDB wiki

Here are the steps for a basic CRUD (Create,Remove,Update & Delete) operations on MongoDB with Node.js

1. Create a folder c:\node\mongotest

2. Go to the directory where you have extracted the mongodb files and type in

mongod –dbpath c:\node\mongotest

This  will  start the database.

3. Here are the main functions of the code.

Connect to the mongodb database

var MongoClient = require('mongodb').MongoClient;
// Connect to the db
MongoClient.connect(“mongodb://localhost:27017/exampleDb”, function(err, db) {
if(!err) {
console.log(“We are connected”);
}

4. Create a collection of documents

//Create a collection test
console.log(“Creating a collection test”);
var collection = db.collection(‘test’);

5. Insert documents into the collection

//Create documents to insert
var doc1 = {‘hello’:’doc1′};
var doc2 = {‘hello’:’doc2′};
var lotsOfDocs = [{‘hello’:’doc3′}, {‘hello’:’doc4′}];
//Insert the docs
console.log(“Inserting the docs”);
collection.insert(doc1,function(err,result){});
collection.insert(doc2, {w:1}, function(err, result) {});

6. Update the inserted documents as follows

//Updating
var doc3 = {key:1,value:1};
collection.insert(doc3,{w:1},function(err,result) {
if(err) {
console.log(‘Could not insert’);
}
collection.update({key:1},{$set:{value:2}},{w:1},function(err,result) {});
});

7. Delete specific  documents from the database. Note: The remove() command requires a callback which I have included separately instead of the standard anonymous callback style

var mycallback = function(err,results) {
console.log(“mycallback”);
if(err) throw err;
}
//Deleting documents
console.log(“The delete operation”);
var doc4=[{key1:1},{key2:2},{key3:3}];
//Insert the document and then remove
collection.insert(doc4,{w:1},function(err,result) {
collection.remove({key1:1},mycallback);
collection.remove({key4:4},{w:1},mycallback);
});

8. Finally retrieve the inserted/updated records from the database

var stream = collection.find({mykey:{$ne:2}}).stream();
console.log(“Printing values…”);
stream.on(“data”, function(item) {
console.log(item);
});
stream.on(“end”, function() {});

The stream.on(“data”,) retrieves all the data till it encounters a stream.on(“end”).

So if I execute the above code I get the following output

C:\test \mongotest>node app3.js
We are connected
Creating a collection test
Inserting the docs
The delete operation
Printing values…
{ _id: 53c27ecbd5f4c59c1a2a5d39, hello: ‘doc1’ }
{ _id: 53c27ecbd5f4c59c1a2a5d3a, hello: ‘doc2’ }
{ _id: 53c27ecbd5f4c59c1a2a5d3b, key: 1, value: 1 }
{ _id: 53c27ecbd5f4c59c1a2a5d3c, key1: 1 }
{ _id: 53c27ecbd5f4c59c1a2a5d3d, key2: 2 }
{ _id: 53c27ecbd5f4c59c1a2a5d3e, key3: 3 }
mycallback
mycallback

The code can be cloned from Github at node-mongo

Also see
1. A Bluemix recipe with MongoDB and Node.js
2. Spicing up IBM Bluemix with MongoDB and NodeExpress
3. A Cloud Medley with IBM’s Bluemix, Cloudant and Node.js
4. Rock N’ Roll with Bluemix, Cloudant & NodeExpress


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Mixing Twilio with IBM Bluemix

This post walks you through the steps to get started with Twilio on IBM’s Bluemix. Twilio comes as a service that you can add  to your Mobile Cloud or Node.js app. Here’s a quick look at Twilio. Twilio, is a cloud communications IaaS organization which  allows you use standard web languages to build voice, SMS and VOIP applications via a Web API.

Twilio provides the  ability to build VOIP applications using APIs. Twilio itself resides in the cloud and is always available. It also provides SIP integration which means that it can be integrated with Soft switches. Twilio looks really  interesting with its ability to combine the  cloud, Web and VOIP, SMS  and  the like.

This post barely scratches the surface of Twilio & Blue mix. This article provides aa hands-on experience for integration of Twilio with Bluemix and is based on this Twilio blog post. It enables you to send a SMS to your mobile phone by typing in a URL.

As in my earlier post the steps are

1) Fire-up a Node.js  Webstarter application from the  Bluemix dashboard.  In my case I have named the application websms. Once this is up and running

2) Click Add a Service and under ‘Web and Application’ choose Twilio.

3) Enter a  name for the Twilio service. You will also need the Account SID and Authorization token

4) For this go to http://www.twilio.com and sign up2

5) Once you have registered, go to your Dashboard for the Account SID and Auth Token. If the Auth token is encrypted, you can click the ‘lock’ symbol to display the Auth token in plain text.

6) Enter the Accout SID and Auth Token in the Twilio service in Bluemix

7)  To get started you can simply  fork my Twilio  websms code from devops.

8) Now clone the code into a folder you create as follows

git clone https://hub.jazz.net/git/tvganesh/websms

9) You will need to modify the following files

package.json

manifest.yml

app.js

 

10) You can create package.json by running
npm init. Make sure you enter the name of the application you created in Bluemix. In my case it is “websms’ For the rest of the options you can choose the default. Here is the package.json file
"name": "websms",
"version": "0.0.0",
"description": "This README.md file is displayed on your project page. You should edit this \r file to describe your project, including instructions for building and \r running the project, pointers to the license under which you are making the \r project available, and anything else you think would be useful for others to\r know.",
"main": "app.js",
"dependencies": {
"gopher": "^0.0.7",
"express": "^3.12.0",
"twilio": "^1.6.0",
"ejs": "^1.0.0"
},
"devDependencies": {},
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"repository": {
"type": "git",
"url": "https://hub.jazz.net/git/tvganesh/websms"
},
"author": "",
"license": "ISC"
}

11) In the manifest.yml make sure you enter the name of your application and the host

applications:
- host: websms
disk: 1024M
name: websms
command: node app.js
path: .
domain: <your domain>
mem: 128M
instances: 1

12) Lastly make changes to your app.js.

// dependencies
var app = require('gopher'),
twilio = require('twilio');
var config = JSON.parse(process.env.VCAP_SERVICES);
var twilioSid, twilioToken;
config['user-provided'].forEach(function(service) {
if (service.name == 'Twilio') {
twilioSid = service.credentials.accountSID;
twilioToken = service.credentials.authToken;
}
});
// URL test
app.get('/', function(request, response) {
var client = new twilio.RestClient(twilioSid, twilioToken);
client.sendMessage({
to:'<Your mobile number>',
from:'<Number from Twilio dashboard',
body:'Twilio notification through Bluemix!'
}, function(err, message) {
response.send('Message sent! ID: '+message.sid);
});
});

13) After you have made the changes you will need to push the changes to Bluemix using the command line based ‘cf’ tool
14) Login into cf with
cf login – a http://api.ng.bluemix.net

15) Push the websms onto bluemix

16) In the folder where you websms files reside entr the following command
cf push websms -p . -m 512M

17) This should push the code to Bluemix.
Note: If you happen to get a
Server error, status code: 400, error code: 170001, message: Staging error: cannot get instances since staging failed
then you need to make sure to check the changes made to  files app.js, package.,json or the manigfest,yml.

18)  If all things went smoothly, go to your Bluemix dashboard and click the link adjacent to the Routes. You should see that an SMS has been sent as shown

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19) Your mobile should now display the message that was sent as shown below
Screenshot_2014-06-22-13-41-44

20) Check the  analytics in your Twilio dashboard
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Disclaimer: This article represents the author’s viewpoint only and doesn’t necessarily represent IBM’s positions, strategies or opinions

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Get your feet wet with IBM Bluemix

This post provides the initial steps to get started on IBM’s Bluemix (currently in beta). Bluemix is open-standard, cloud based Platform-as-a-Service (PaaS) from IBM. Bluemix allows one to quickly put together mobile, web, Big Data, IoT applications. Bluemix is an implementation of IBM’s Open Cloud Architecture, Cloud Foundry which enables developers to rapidly build, deploy, and manage their cloud applications. The developers can tap into a growing ecosystem of available services and runtime frameworks.

Bluemix uses the Softlayer infrastructure to host the user applications. Clients/developers interact with Bluemix either with HTTP or REST as shown below
8

Here are the steps to get going on Bluemix

First things first

I would suggest that you get all the registrations and installations right away.

Bluemix dashboard– Get started by creating an account on Bluemix. This will provide you access to the Bluemix’s dashboard from which you can quickly create applications (mobile, Web, IoT, BigData) etc

Devops: Register for an account with Devops. Devops allows you to easily develop, deploy and track your code online. Devops also allows you to collaborate with others by forking code from their Git repositories

Cf Interface : Install the Command line interface ‘cf” to Bluemix. The ‘cf’ command interface is built with Google’s Go programming language. With ‘cf ‘you can login to Bluemix, create an application, add services and manage your application. You can also do this from the Bluemix’es dashboard.

Install Git: There are multiple ways to develop code for Bluemix. Git command line happens to be one of them, So it makes sense to have this installed. You can install this from this link https://hub.jazz.net/tutorials/clients#installing_git

Install Node.js:The application that this post discusses is based on a Node.js based application so it will help to have it installed. Node.js is a platform that enables building of fast, scalable network applications and created by Ryan Dahl.

Kicking off Bluemix : A good first application to get moving on in Bluemix is the already available Sentiment Analysis of Twitter. This application uses the Node.js ‘sentiment’ module to perform some basic sentiment analysis.

The quickest and most painless way to get started on Bluemix is to ‘fork’ the code for Sentiment Analysis from Devops.

1) Login to your Devops account. Click the following Sentiments link from Devops, in which I have created a slight modification to the sentiment analysis application. You can also clone the code from GitHub at sentiments.

2) Click the Edit Code button at the top. This will open the files and directories in this project (see picture below)

3) Next click the “Fork’ button on the panel on the left side. This will create a copy of the above code in your own repository (see picture below )

1

4) The Twitter sentiment analysis code is in app.js written in Node.js. You can make changes to the code as needed. I have made a few modifications to the code that I had forked. I added changes which adds a textual output of the Twitter sentiment

;

How to make code changes with Web IDE

5) To make code changes double click the app.js file. This will open up the code window. You can use the GUI based IDE to make the code changes and merge with the master branch, The steps are
a) Make the necessary changes and click the symbol shown

2

3. This will open a new window as shown below

3

4) Click the ‘Stage to change’ button.

5) This will move the changes to Staged. Click the ‘Commit’ button and enter the reason for the change and click the “Submit’

4

6) This will move the changes from ‘Staged’ to ‘Commits for master branch’

7) Now click ‘Push all’ and click ‘Ok’ in the Git Push popup window. This will merge the changes into the master branch.

8) Once this done click ‘Build & Deploy’ button

9) Your changes will transition from ‘Pending’ to ‘OK’. Now click the ‘Manage’ button. This will deploy the application with the latest changes on to Bluemix.

10) Do the following to populate the details for the parameters below  with a Twitter app that you create for your application

var tweeter = new twitter({
consumer_key:  <your API key>,
consumer_secret: <your API secret>,
access_token_key:<your access token >,
access_token_secret: <your access token secret>
});

11) To do this log into http://dev.twitter.com

12) Click My applications where your picture is displayed and then click Create application.

13) Enter the details for Name,Description & Website (can be any valid website) and then click Create Twitter application.. This will create the Twitter application.

1

14) Click the API tab. Scroll down to the bottom and click “Create my access token”.

15) This will generate the Access token & Access token secret. Enter all the details (API Key, API secret, Access Token, Access Token secret into app.js and push to the master branch before deploying on Bluemix

 

Code changes with Git command line

11) Incidentally the changes to code can also be made through the Git command shell as follows

a) git clone https://hub.jazz.net/git/tvganesh/sentiments

b) Modify the code using any editor and save the changes

c) Go the directory containing the files and do

git add *

d) git commit -m “Cosmetic” app.js

e) git push

This will push the changes to the git repository in the master branch

8) Click the ‘Build & deploy’ in the top right corner. You should see this

5

9) Click the ‘Manage’ button which will push the application onto the BlueMix

10) To test this application click the link next to ‘Routes’ . Enter a phrase that you would like to search and hit ‘Go’

6

You should see the application checking Twitter periodically for the tweets.

7

Thats it! You have built your first Bluemix application.

The ability to integrate Node.js into your cloud application allows one to easily create powerful applications.

Hasta la vista! I’ll be back!

Disclaimer: This article represents the author’s viewpoint only and doesn’t necessarily represent IBM’s positions, strategies or opinions

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