I’m a big fan of Stack Overflow and I tend to contribute regularly (am currently in the top 0.X%). In this category (stackoverflow) of posts I will will be posting my top rated questions and answers. This, btw, is allowed as explained in the meta thread here.

I actually answered this question by userArlind a:

I’m using AdMob plugin in Ionic and with this code I show an Interstital ad:

function initAd(){

 // it will display smart banner at top center, using the default options
 if(AdMob) AdMob.createBanner( {
                          adId: admobid.banner,
                          bannerId: admobid.banner,
                          position:AdMob.AD_POSITION.BOTTOM_CENTER,
                          autoShow: true,
                          isTesting: false,
                          success: function(){
                          console.log('banner created');
                          },
                          error: function(){
                         console.log('failed to create banner');
                          }
                          } );

                                       window.AdMob.prepareInterstitial( 
                           {adId:admobid.interstitial, autoShow:false} );
    window.AdMob.showInterstitial();

 }

Is there a way to show intersitial ad every 2 minutes? Someone told me to add this:

setInterval(showInterstitial,1*60*1000)

but I don’t know where to add?

My answer was:

If you would like to show it every 2 minutes you should use:

setInterval(window.AdMob.showInterstitial, 2*60*1000);

and you should add it just before the closing bracket of your initAdd function:

function initAd(){


 // it will display smart banner at top center, using the default options
 if(AdMob) AdMob.createBanner( {
                          adId: admobid.banner,
                          bannerId: admobid.banner,
                          position:AdMob.AD_POSITION.BOTTOM_CENTER,
                          autoShow: true,
                          isTesting: false,
                          success: function(){
                          console.log('banner created');
                          },
                          error: function(){
                         console.log('failed to create banner');
                          }
                          } );

                                       window.AdMob.prepareInterstitial( 
                           {adId:admobid.interstitial, autoShow:false} );
    window.AdMob.showInterstitial();
  
  
  
  //!!!add the code here!!! - so, just paste what I wrote above:
  setInterval(window.AdMob.showInterstitial, 2*60*1000);

 }

You can see a simple setInterval usage on this jsFiddle example:

function a(){
    alert("hi every 2 seconds");
};

setInterval(a, 2*1000);

The reason why you shouldn’t call it like this (note the brackets after a): setInterval(a(), 2*1000); is that then your function would be called only once (you would see only one alert popping up). Example on jsFiddle:

function a(){
    alert("hi every 2 seconds");
};

setInterval(a(), 2*1000);

My notes from the book Choose Yourself! by James Altucher:

Learned man aims for more, but the wise man decreases, and then decreases again.

The thing that really matters in this world are relationships you have with people you love and meaningful things that you do. Haters don’t fit anywhere into that.

• Sleep eight hours
• Eat two meals instead of three (I don’t agree with this one personally )
• No TV
• No junk food
• No complaining for one whole day
• No gossip
• Return an email from five years ago
• Express thanks to a friend
• Watch a funny movie
• List down a bunch of ideas
• Read spiritual text
• Say to yourself in the morning “I’m going to save a life today”
• Pick up a hobby
• Surprise someone
• Think about five people you’re grateful for
• Forgive someone – write it on a paper and burn it
• Take the stairs
• Don’t see yes when you think no
• Tell someone you love them
• Deep breathing

After a certain salary point, your marginal happiness doesn’t go up.

Writing a book never really makes a lot of money, but there are all these additional benefits of writing a book: consulting, speaking, TV shows, ghost writing, email list to market further. 

In order to get good ideas read two hours a day and write ten ideas a day.

Wake up and think of five people you’re grateful for.

Meditation – don’t time travel, be in the present.

Negotiation is worthless, sales is everything.

Better to sell early than to go broke.

Simple effort will give you a customer for life – always give a little extra. 

If you love something you get knowledge, the contacts, you’ll build something nobody else has, you’ll wow the customers.

… and that’s Stephen King – all it took was a few weeks of not writing to fall completely off his game even though he’s one of the best in the world at what he does.

The idea muscle has to be exercised daily.

Activate another part of your brain. Best ideas come from collision between  newer  and older ideas. Take two older, unrelated ideas and make them have sex.

Perfectionism may harm you. Embrace failure and get ASAP on your feet again.

Delegate jobs to someone else.

If you can’t help yourself you won’t be able to help others.

Be physically, emotionally, spiritually and mentally healthy.

I’m a big fan of Stack Overflow and I tend to contribute regularly (am currently in the top 0.X%). In this category (stackoverflow) of posts I will will be posting my top rated questions and answers. This, btw, is allowed as explained in the meta thread here.

My question was:

The problem I’m facing, as outlined in the code, is that I can’t seem to find out how to bind the second checkboxes (created with ng-repeat) to some model which I would then be able to use further down the code (showing/hiding yet another set of options). Also, I managed to show the additional number of inputs based on the count parameter in the $scope.availableOptions by using the $scope.getItterator function, but now I don’t see how would I access the values of these checkboxes? I know I have to somehow use the option “ng-model” but am failing to do so, so any help appreciated.

My code is here, but am showing it here too:

HTML:

<div ng-controller='MyCtrl'>
    Show additional options <input type="checkbox" ng-model="additionalOptions">
    <div ng-show="additionalOptions">
        <ul>
            <li ng-repeat="option in availableOptions">
                <label class="checkbox" for="opt_{{option.id}}">
                    <input type="checkbox" name="opt_{{option.id}}" id="opt_{{option.}}" />
                    {{option.name}}

                    <ul ng-show="if the upper checkbox is clicked">
                        <li>
                            <input type="text" ng-repeat="i in getItterator(option.count)" ng-model="SOME_VALUE_TO_BE_USED_BELOW"/>
                            Output the value based on what's entered above in the textboxes (SOME_VALUE_TO_BE_USED_BELOW)
                        </li>   
                    </ul>
                </label>
            </li>
        </ul>
    </div>
</div>

and my js:

function MyCtrl($scope) {
    $scope.availableOptions = [{"id":"1","name":"easy","count":"2"},{"id":"2","name":"medium","count":"3"},{"id":"3","name":"hard","count":"2"}];

    $scope.getItterator=function(n){
        var a = new Array();

        for(var i=1; i <= n; i++)
            a.push(i);

        return a;       
    };
}

The answer, by user Khanh TO, was:

Try ng-model="option.checked":

<input type="checkbox" name="opt_{{option.id}}" id="opt_{{option.}}" ng-model="option.checked"/>

And then you can access this property further below like this:

<ul ng-show="option.checked">

DEMO

If you need to also reference the text box inputs. You create a new property (values) on the option. Like this:

{"id":"1","name":"easy","count":"2",values:[]}

Html:

<div ng-repeat="i in getItterator(option.count)">
     <input type="text"  ng-model="option.values[$index]"/>
      {{option.values[$index]}}
</div>

DEMO

When I was preparing this post I bought a domain just for testing purposes called nikola-dev.com and I wanted to have Node.js apps running on this VPS (behind a NGINX running as proxy) but that they would be accessible from different domains (for example mean.nikola-dev.com). Below are the steps I needed to take in order to make this happen:

1. Clearly, have a droplet on DigitalOcean
2. Buy a domain (where ever you buy it, make sure you use Honey, to get the best price)
3. Edit the Nameserver information in the admin dashboard of your domain provider (where you bought the domain) to the following three records:
   ns1.digitalocean.com, ns2.digitalocean.com, ns3.digitalocean.com
4. Add the domain on DigitalOcean DNS settings page:
   
5. Delete /etc/nginx/sites-enabled/default
6. Create /etc/nginx/sites-available/nikola-dev.com file with the following content (this will be a simple single HTML file which will list the available test apps on this server):

   server {
       listen 80;
       server_name nikola-dev.com;
       root /var/www/nikola-dev.com/public_html;
   }

7. Create /etc/nginx/sites-available/mean.nikola-dev.com file with the following content (this will serve the actual Node.js app that we’re building in this tutorial):

   server {
       listen 80;
   
       server_name mean.nikola-dev.com;
   
       location / {
           proxy_pass http://127.0.0.1:3000;
           proxy_http_version 1.1;
           proxy_set_header Upgrade $http_upgrade;
           proxy_set_header Connection 'upgrade';
           proxy_set_header Host $host;
           proxy_cache_bypass $http_upgrade;
       }
   }

8. Restart NGINX:

   sudo service nginx restart

Clearly, if you would need to add more subdomains, just repeat the steps from step 6 onward. Of course, you would need to put your other Node.js apps on different ports, since only one app can work on one port.

My notes from an awesome book EDGY Conversations by Dan Waldschmidt, which I rated 5/5 on my Shelfari account:

Success is not about what you do, it’s about what you are.

Who and what do you want to be, and why?

Van Gogh sold only one picture during his lifetime.

You have to look within yourself and challenge the demons that hold you back from being successful.

You’ll never rise to be a champion if you can’t pass the fear and the failure and the excuses holding you back.

You have to believe that you can be amazing regardless of where or who you are right now.

Carl Sugarfoot Joseph

Simply getting up one hour earlier a day for 50 years equates to an extra 2281 business days, or 6.25 years of conquest.

You win more when you fight more.

Success is an attitude: don’t be afraid to be extreme, be disciplined, be giving, understand the why human factor.

Are you willing to commit to extreme behavior? When you decide that it’s going to be hard. When you know that you have to outwork, outthink, outplay, outmuscle everything you do from this day forward extreme behavior actually becomes a great way to focus what you do.

Small jump forward is actually a big leap backwards.

You want harmony, not balance.

People really want to believe effort is a myth. I think we’ve been tricked by the few lucky people on the top of the heap. We see the folks who managed to get by and it’s easy to forget that these guys are the exceptions. For everyone else effort is directly related to success. You don’t get to choose luck, effort on the other hand is available there all the time.

Jerry Rice

Only limits that exist are the ones in your head.

With discipline and effort you can do just about anything.

The average age of a successful interpreter is mid 40s.

Effort is more than ‘if you pay me more, I’ll work harder’, it’s about not cheating yourself out of your potential.

Cliff Young

Passion is the antidote to the setbacks you will surely face on the way to success. It’s that often illogical passion and emotion that allows you to keep going long after it makes sense. When you put enough of yourself into something you will do whatever it takes to come out as a winner.

Anyone can conquer when the odds are in their favor. The challenge is to do what it’s hard and the noble and the right when you are sick and tired and tired and sick.

It takes discipline to keep moving forward.

It’s not only what you’re willing to do what will make you successful, it’s also what you’re willing to do without, until you get there.

You may spend a decade of sleepless nights until you make it to the finish line – and you need to plan for that.

Plan to work harder than you ever imagined possible. And then, double that effort!

Your plan should be bigger than simply “not losing”.

Have a giving mindset.

Success and living in balance life should not be in the same sentence.

Give expecting nothing in return, and you will change people’s lives.

Marianne Williamson: “Our deepest fear is not that we are inadequate. Our deepest fear is that we are powerful beyond measure. It is our light, not our darkness, that most frightens us. We ask ourselves, who am I to be brilliant, gorgeous, talented, fabulous? Actually, who are you not to be? You are a child of God. Your playing small doesn’t serve the world. There’s nothing enlightened about shrinking so that other people won’t feel insecure around you. We are all meant to shine, as children do. We were born to make manifest the glory of God that is within us. It’s not just in some of us; it’s in everyone. And as we let our own light shine, we unconsciously give other people permission to do the same. As we’re liberated from our own fear, our presence automatically liberates others.”

Derek Redmond

Brain handling new information: If it’s boring or expected, brain ignores it. If it’s too complex, the brain dramatically summarizes it. If it’s threatening it prepares for “fight or flight” scenario.

What do you think about most is what you become. You are today who you thought you would be. You will be in the future who you think you want to be today.

Everything in life starts with your thinking. If you let fear drive your thoughts, you’ll never do the things that lead to success. You’re actually a lot stronger than the fear in your mind lets you think you are.

If you want to dominate, control your thoughts.

Successes is what you decide it is, not what other people tell you it should be. You decide what is right for you.

You,  believe in you…

If you happen to like the image above, and you’re thinking to yourself how cool it would look like as a sticker, take a look at a few that I made.

TL;DR

In my previous tutorial about the MEAN stack, I showed you how to get your MEAN stack up and running in less than a minute. In this tutorial I’m going to show you how to add a comment field to an existing MEAN.js Article example. You can see the finished application on http://mean.nikola-dev.com, and you can clone the source on GitHub.

I actually answered the question Adding comments to MEAN.JS articles on StackOverflow, and this posts is kind of an addition to that answer, with pictures (everyone likes pictures, right? 😉).

[toc]

Starting point

So, if you’ve followed the (ah, yet again mentioned) previous tutorial you have a running MEAN.js example on your DigitalOcean Droplet, whose front page looks like the image below if you’re logged in. You can simply register via mail (I didn’t implement any other methods like Facebook, Google, LinkedIn or GitHub for this tutorial).

Please note that yes, you can run this example locally on your computer too, but you would have to manually install the whole MEAN stack (namely MongoDB, Express.js and Node.js). If you wish to do so, you can take a look at the steps needed to do this from a rather popular tutorial How to get started on the MEAN stack. Rest of the tutorial, however, assumes you are testing this on DigitalOcean Droplet.

How to add a subdomain for Nodejs application on DigitalOcean droplet

When I was preparing this post I bought a domain just for testing purposes called nikola-dev.com and I wanted to have Node.js apps running on this VPS (behind a NGINX running as proxy, as we set it up in previous tutorial) but that they would be accessible from different subdomains (for example mean.nikola-dev.com). Below are the steps I needed to take in order to make this happen:

1. Buy a domain (clearly you have done so )
2. Edit the Nameserver information in the admin dashboard of your domain provider (where you bought the domain) to the following three records:
   ns1.digitalocean.com, ns2.digitalocean.com, ns3.digitalocean.com
3. Add the domain on DigitalOcean DNS settings page:
   
4. Delete /etc/nginx/sites-enabled/default
5. Create /etc/nginx/sites-available/nikola-dev.com file with the following content (this will be a simple single HTML file which will list the available test apps on this server):

   server {
       listen 80;
       server_name nikola-dev.com;
       root /var/www/nikola-dev.com/public_html;
   }

6. Create /etc/nginx/sites-available/mean.nikola-dev.com file with the following content (this will serve the actual Node.js app that we’re building in this tutorial):

   server {
       listen 80;
   
       server_name mean.nikola-dev.com;
   
       location / {
           proxy_pass http://127.0.0.1:3000;
           proxy_http_version 1.1;
           proxy_set_header Upgrade $http_upgrade;
           proxy_set_header Connection 'upgrade';
           proxy_set_header Host $host;
           proxy_cache_bypass $http_upgrade;
       }
   }

7. Restart NGINX:

   sudo service nginx restart

Adding a comment field to Article example

1. In the file app/models/article.server.model.js add:

   comment: {
   	type: String,
   	default: '',
   	trim: true
   },

   For the reference, the whole app/models/article.server.model.js file contents should look like this:

   'use strict';
   
   /**
    * Module dependencies.
    */
   var mongoose = require('mongoose'),
           Schema = mongoose.Schema;
   
   /**
    * Article Schema
    */
   var ArticleSchema = new Schema({
           created: {
                   type: Date,
                   default: Date.now
           },
           title: {
                   type: String,
                   default: '',
                   trim: true,
                   required: 'Title cannot be blank'
           },
           content: {
                   type: String,
                   default: '',
                   trim: true
           },
           user: {
                   type: Schema.ObjectId,
                   ref: 'User'
           },
           comment: {
                   type: String,
                   default: '',
                   trim: true
           }
   });
   
   mongoose.model('Article', ArticleSchema);

2. In the file public/modules/articles/views/create-article.client.view.html add the following content before the submit button:

   <div class="form-group">
   	<label class="control-label" for="comment">Comment</label>
   	<div class="controls">
   		<textarea name="comment" data-ng-model="comment" id="comment" class="form-control" cols="30" rows="10" placeholder="Comment"></textarea>
   	</div>
   </div>

   For the reference, the whole public/modules/articles/views/create-article.client.view.html file contents should look like this:

   <section data-ng-controller="ArticlesController">
           <div class="page-header">
                   <h1>New Article</h1>
           </div>
           <div class="col-md-12">
                   <form name="articleForm" class="form-horizontal" data-ng-submit="create()" novalidate>
                           <fieldset>
                                   <div class="form-group" ng-class="{ 'has-error': articleForm.title.$dirty && articleForm.title.$invalid }">
                                           <label class="control-label" for="title">Title</label>
                                           <div class="controls">
                                                   <input name="title" type="text" data-ng-model="title" id="title" class="form-control" placeholder="Title" required>
                                           </div>
                                   </div>
                                   <div class="form-group">
                                           <label class="control-label" for="content">Content</label>
                                           <div class="controls">
                                                   <textarea name="content" data-ng-model="content" id="content" class="form-control" cols="30" rows="10" placeholder="Content"></textarea>
                                           </div>
                                   </div>
   
   								<div class="form-group">
   								        <label class="control-label" for="comment">Comment</label>
   								        <div class="controls">
   								                <textarea name="comment" data-ng-model="comment" id="comment" class="form-control" cols="30" rows="10" placeholder="Comment"></textarea>
   								        </div>
   								</div>
   								
                                   <div class="form-group">
                                           <input type="submit" class="btn btn-default">
                                   </div>
                                   <div data-ng-show="error" class="text-danger">
                                           <strong data-ng-bind="error"></strong>
                                   </div>
                           </fieldset>
                   </form>
           </div>
   </section>

3. In the file public/modules/articles/controllers/articles.client.controller.js adjust the create function to be:

   var article = new Articles({
   title: this.title,
   content: this.content,
   comment: this.comment
   });

   For the reference, the whole public/modules/articles/controllers/articles.client.controller.js file contents should look like this:

   'use strict';
   
   angular.module('articles').controller('ArticlesController', ['$scope', '$stateParams', '$location', 'Authentication', 'Articles',
           function($scope, $stateParams, $location, Authentication, Articles) {
                   $scope.authentication = Authentication;
   
                   $scope.create = function() {
                           var article = new Articles({
                                   title: this.title,
                                   content: this.content,
                                   comment: this.comment
                           });
                           article.$save(function(response) {
                                   $location.path('articles/' + response._id);
   
                                   $scope.title = '';
                                   $scope.content = '';
                           }, function(errorResponse) {
                                   $scope.error = errorResponse.data.message;
                           });
                   };
   
                   $scope.remove = function(article) {
                           if (article) {
                                   article.$remove();
   
                                   for (var i in $scope.articles) {
                                           if ($scope.articles[i] === article) {
                                                   $scope.articles.splice(i, 1);
                                           }
                                   }
                           } else {
                                   $scope.article.$remove(function() {
                                           $location.path('articles');
                                   });
                           }
                   };
   
                   $scope.update = function() {
                           var article = $scope.article;
   
                           article.$update(function() {
                                   $location.path('articles/' + article._id);
                           }, function(errorResponse) {
                                   $scope.error = errorResponse.data.message;
                           });
                   };
   
                   $scope.find = function() {
                           $scope.articles = Articles.query();
                   };
   
                   $scope.findOne = function() {
                           $scope.article = Articles.get({
                                   articleId: $stateParams.articleId
                           });
                   };
           }
   ]);
   

4. In the file public/modules/articles/views/view-article.client.view.html add this just before the closing section tag:

   <p data-ng-bind="article.comment"></p>

   For the reference, the whole public/modules/articles/views/view-article.client.view.html file contents should look like this:

   <section data-ng-controller="ArticlesController" data-ng-init="findOne()">
           <div class="page-header">
                   <h1 data-ng-bind="article.title"></h1>
           </div>
           <div class="pull-right" data-ng-show="authentication.user._id == article.user._id">
                   <a class="btn btn-primary" href="/#!/articles/{{article._id}}/edit">
                           <i class="glyphicon glyphicon-edit"></i>
                   </a>
                   <a class="btn btn-primary" data-ng-click="remove();">
                           <i class="glyphicon glyphicon-trash"></i>
                   </a>
           </div>
           <small>
                   <em class="text-muted">
                           Posted on
                           <span data-ng-bind="article.created | date:'mediumDate'"></span>
                           by
                           <span data-ng-bind="article.user.displayName"></span>
                   </em>
           </small>
           <p class="lead" data-ng-bind="article.content"></p>
           <p data-ng-bind="article.comment"></p>
   </section>

5. This is it, now you have a new field comment for each article:
   Once added, you’ll see the comment in the article list:
6. What you should do now, and I hope it’s clear form these instructions here, is alter the editing part of the articles, so that they include the comment field.

Where to go from here?

This tutorial should have given you the basic understanding on how to add additional fields to the MEAN.js Article example, and you should be confident enough to starting adding your own fields and altering the example to your liking.

In the next tutorial we’ll take a look at how to add Image CRUD module to MEAN.js application with a single Yeoman command (I will update the link here once the tutorial is finished).

If you want to learn more about the MEAN stack, take a look at the blog2book Getting MEAN with MEMEs (yes, you can download it for free, though a coffee would be nice ).

Update: Before I got rid of the Lenovo laptop, it looked like this:

TL;DR: Stickers can be seen here on StickerMule. If you happen to signup up via this link, you’ll get 10$ off of your next purchase. Thank me later… 

Ok, ok, so before you start jumping about the title for thinking how did I not know about Apple buying Lenovo, and start calling your wallstreet woolf to get you a deal on some Apple stocks before they skyrocket again, let me calm you down by saying it’s just the stickers, it’s just the stickers 😉

So, as you may know I’m pretty much into Ionic framework lately and I stumbled upon some Ionic stickers on StickerMule and added them to cart immediately.

Then, I browsed through the site and as it seemed they offer you to upload your own stickers. So, I contacted their support team, and boy can I tell you their response time was fast. Like, super fast. They told me the details about the sizes and image quality in order for it to look good when printed.

Since I very much like MEAN stack and there were no stickers for it available yet, I made my own and you can take a look at them here on StickerMule.

I also ordered the sample pack for just 1$. The shipping price via air mail to Croatia was about 6$, but I have to say the shipping was indeed fast (less than a week, which to our country is, trust me I’m lying, fast).

The quality of the stickers is very good, and I like the personal touch where the person who packaged the stickers signed it by hand (see the image below).

Here are some pictures of the arrived lot:

Here’s the signature of the person who packaged it – thanks Wendy!

Here’s how my laptop now looks from the inside :). Yes, keep calm folks, I use R.A.T 7 and drink too much coffee too.

And here’s how it looks from the outside. Before I only had the Apple logo in the middle (yeah, I happen to like Apple products, sue me  – erm, so why Lenovo then? Ah, that’s another story, ping me on mail or comments if you’re really intrigued). The blank space on the right hand side is left for a new sticker that’s coming soon 🙂

Anyways, StickerMule has my recommendation for being awesome when it comes to stickers!

I’m a big fan of Stack Overflow and I tend to contribute regularly (am currently in the top 0.X%). In this category (stackoverflow) of posts I will will be posting my top rated questions and answers. This, btw, is allowed as explained in the meta thread here.

My question was:

I tried to run this code: cordova plugin add cordova-plugin-whitelist but what I keep getting is this:

Fetching plugin "cordova-plugin-whitelist" via plugin registry Error: 404 Not Found: cordova-plugin-whitelist at RegClient.<anonymous> (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/node_modules/npm/node_modules/npm-registry-client/lib/request.js:304:14) at Request._callback (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/node_modules/npm/node_modules/npm-registry-client/lib/request.js:246:65) at Request.self.callback (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/node_modules/npm/node_modules/request/request.js:236:22) at Request.emit (events.js:98:17) at Request.<anonymous> (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/node_modules/npm/node_modules/request/request.js:1142:14) at Request.emit (events.js:117:20) at IncomingMessage.<anonymous> (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/node_modules/npm/node_modules/request/request.js:1096:12) at IncomingMessage.emit (events.js:117:20) at _stream_readable.js:943:16 at process._tickCallback (node.js:419:13)

Any ideas?

I actually found the answer to this myself:

From an official blog post, Cordova is moving their plugins to npm.

I installed the cordova-plugin-whitelist easily now with npm:

npm install cordova-plugin-whitelist

Over the past year I’ve tried lots of options for hosting my MEAN applications, and finally I’ve settled for DigitalOcean. It’s true what they advertise – that you can have a SSD cloud server up and running in less than 55 seconds. However, you don’t have to go spending your hard earned cash just yet – I have a special deal with DigitalOcean and you can signup via this link and get 10$ immediately, which will be enough for 2 full months of non stop server running. They even provide you with API so that you can control your server, and this tutorial shows you how.

I don’t want to make it look like I’m pushing you on DigitalOcean – you can sign up with someone else if you like, I just recommend them because I had a good experience with them in the past and because it’s so easy to get a MEAN stack all pre-installed (more on this in a bit) and ready for use.

Create a droplet

Once you complete the sign up on DigitalOcean  you will be presented with a similar screen, as show on the image below, where you have to click on the Create Droplet button:

Next, you have to name your droplet (cool name the folks at DigitalOcean chose to call their server instances) and select the size (the smallest one will be just fine here), just as it’s shown on the image below:

After this, you have to choose a region, as shown on the image below. Naturally, you’ll want to choose some location which is closer to your targeted audience.

Now comes the most awesome part. In Select Image section you have tons of options ranging from the barebones distributions (Centos, Ubuntu, Debian, etc.), to the pre-built stacks (LAMP, LEMP, WordPress, ROR, MEAN, etc.) like shown on the image below. Here you have to choose the MEAN on 14.04 option (YMMV on the exact number), and this is awesome because with this droplet you won’t have to go through the hassle of installing Node.js, Express and MongoDB as we did in the first tutorial – it will be already done and waiting for you! B-E-A-utiful!

Then, just wait a few seconds and your droplet will be ready:

You’ll be redirected to the dashboard (once the droplet is created) which will look something like the image below:

Connect to the droplet

On your email address you will receive instructions which will look something like on the image below:

Now, using a SSH client of your choice (I’m currently on Windows so not much leeway here :)) connect to the droplet. The image below shows the setting from the Putty SSH client on Windows:

You have to connect with the root user and the password that was emailed to you. However, immediately upon logging in you will get a notification that you have to change the root’s password, as shown on the image below:

Create a new user

Using root user in linux is bad practice, so now you’re going to create a new user with the following command:

useradd nikola

Of course, you can use any username you want. After this add the user to the sudo group by executing the following command:

gpasswd -a nikola sudo

The sudo group enables the user nikola to use the sudo command when using some commands that are restricted to root user. You can learn more about sudo here. The image below shows the example of the commands I just listed:

Run

Now just run

grunt

and if you visit your ip address on port 3000 you should see:

What you now have running is a well known MEAN.js framework. You may have also heard about MEAN.io and you can learn about the difference in my post about MEAN.io vs MEAN.js.

Use your own domain

In case you bought (or have somewhere hanging in the closet from the 90’s .com boom) a domain that you would like to use to point to your droplet you have to go to the DNS settings and add a domain like shown on the image below:

Also, in your domain registrar (where you bought your domain – think Godaddy, Namecheap, Hostgator, etc.) you have to set the corresponding nameservers to:

• ns1.digitalocean.com
• ns2.digitalocean.com
• ns3.digitalocean.com

You can learn more about this on the official Digital Ocean guide.

Using PM2

Running your Node.js application by hand is, well, not the way we roll. Imagine restarting the app every time something happens, or god forbid application crashes in the middle of the night and you find about it only in the morning – ah the horror. PM2 solves this by:

• allowing you to keep applications alive forever
• reloading applications without downtime
• facilitating common system admin tasks

To install PM2, run the following command:

sudo npm install pm2 -g

To start your process with PM2, run the following command (once in the root of your application):

pm2 start server.js

As you can see from the output shown on the image below, PM2 automatically assigns an App name (based on the filename, without the .js extension) and a PM2 id. PM2 also maintains other information, such as the PID of the process, its current status, and memory usage.

As I mentioned before, the application running under PM2 will be restarted automatically if the application crashes or is killed, but an additional step needs to be taken to get the application to launch on system startup (boot or reboot). The command to do that is the following:

pm2 startup ubuntu

The output of this command will instruct you to execute an additional command which will enable the actual startup on boot or reboot. In my case the note for the additional command was:

sudo env PATH=$PATH:/usr/local/bin pm2 startup ubuntu -u nikola

If you want to learn more about the additional PM2 options you can take a look at this post.

Using NGINX as a Reverse proxy in front of your Node.js application

Though this step is not mandatory, there are several benefits of doing so, as answered in this Stack Overflow question:

• Not having to worry about privileges/setuid for the Node.js process. Only root can bind to port 80 typically. If you let nginx/Apache worry about starting as root, binding to port 80, and then relinquishing its root privileges, it means your Node app doesn’t have to worry about it.
• Serving static files like images, CSS, js, and HTML. Node may be less efficient compared to using a proper static file web server (Node may also be faster in select scenarios, but this is unlikely to be the norm). On top of files serving more efficiently, you won’t have to worry about handling eTags or cache control headers the way you would if you were servings things out of Node. Some frameworks may handle this for you, but you would want to be sure. Regardless, still probably slower.
• More easily display meaningful error pages or fall back onto a static site if your node service crashes. Otherwise users may just get a timed out connection.
• Running another web server in front of Node may help to mitigate security flaws and DoS attacks against Node. For a real-world example, CVE-2013-4450 is prevented by running something like Nginx in front of Node.

So, with being convinced that having NGINX in front of Node.js application is a good thing, following are the steps on how to install and configure it.

First, update the apt-get package lists with the following command:

sudo apt-get update

Then install NGINX using apt-get:

sudo apt-get install nginx

Now open the default server block configuration file for editing:

sudo vi /etc/nginx/sites-available/default

and add this to it:

server {
    listen 80;

    server_name meantodo.com;

    location / {
        proxy_pass http://127.0.0.1:3000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }
}

This configures the web server to respond to requests at its root. Assuming our server is available at http://meantodo.com, accessing it via a web browser would send the request to the application server’s private IP address on port 3000, which would be received and replied to by the Node.js application.

Once you’re done with the setting you have to run the following command which will restart NGINX:

sudo service nginx restart

You can learn more about additional NGINX setting from quite a load of tutorials.

Faking RAM with swap

Since we chose the smallest droplet version of 512 MB we can use swap to make this droplet perform better. Swap is an area on a hard drive that has been designated as a place where the operating system can temporarily store data that it can no longer hold in RAM. For a more indepth tutorial on this you may want to check out official DigitalOcean guide.

In order to allocate a swap file space execute the following command:

sudo fallocate -l 1G /swapfile

Then restrict it to only root user by executing:

sudo chown 600 /swapfile

With the next two commands you actually setup the swap space and enable it:

sudo mkswap /swapfile
sudo swapon /swapfile

To view the swap space information you can execute:

sudo swapon -s

To enable swap automatically when the server restarts you have to add the following content to the /etc/fstab file:

/swapfile   none    swap    sw    0   0

Additionally, there are two more settings worth changing:

• swappiness  – parameter which determines how often your system swaps data out of RAM to the swap space. The value is between 0 and 100 and represents a percentage (60 is the default, but we’ll use 10 since we’re on a VPS)
• vfs_cache_pressure – parameter which determines how much the system will choose to cache inode and dentry information over other data (default value is 100, but we’ll use 50)

In order to make this change append the /etc/sysctl.conf file with the following content:

vm.swappiness=10
vm.vfs_cache_pressure = 50

Other security concerns

If you want to learn more on how to secure your droplet I advise you to go over the steps in the initial server setup with Ubuntu on official DigitalOcean tutorial.

A freakin’ 150+ page MEAN tutorial PDF

This is actually an excerpt from the 4 part tutorial series I wrote for HackHands. If you like you can also take a look at all those posts combined into one big PDF file via LeanPub:

P.S. It’s an intentional typo, since if you’re proud of getting something in production then it’s called a prouduction 😉

P.P.S. You can enter any amount (yes, even 0$) and I won’t take it against you ;), though a coffee would be nice 

 on!

This is a straight to point short tutorial on how to set up NGINX as a reverse proxy in front of a Node.js application, and although this is not mandatory, there are several benefits of doing so, as answered in this Stack Overflow question:

• Not having to worry about privileges/setuid for the Node.js process. Only root can bind to port 80 typically. If you let nginx/Apache worry about starting as root, binding to port 80, and then relinquishing its root privileges, it means your Node app doesn’t have to worry about it.
• Serving static files like images, CSS, js, and HTML. Node may be less efficient compared to using a proper static file web server (Node may also be faster in select scenarios, but this is unlikely to be the norm). On top of files serving more efficiently, you won’t have to worry about handling eTags or cache control headers the way you would if you were servings things out of Node. Some frameworks may handle this for you, but you would want to be sure. Regardless, still probably slower.
• More easily display meaningful error pages or fall back onto a static site if your node service crashes. Otherwise users may just get a timed out connection.
• Running another web server in front of Node may help to mitigate security flaws and DoS attacks against Node. For a real-world example, CVE-2013-4450 is prevented by running something like Nginx in front of Node.

So, with being convinced that having NGINX in front of Node.js application is a good thing, following are the steps on how to install and configure it.

First, update the apt-get package lists with the following command:

sudo apt-get update

Then install NGINX using apt-get:

sudo apt-get install nginx

Now open the default server block configuration file for editing:

sudo vi /etc/nginx/sites-available/default

and add this to it:

server {
    listen 80;

    server_name meantodo.com;

    location / {
        proxy_pass http://127.0.0.1:1337;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }
}

This configures the web server to respond to requests at its root. Assuming our server is available at http://meantodo.com, accessing it via a web browser would send the request to the application server’s private IP address on port 1337, which would be received and replied to by the Node.js application.

Once you’re done with the setting you have to run the following command which will restart NGINX:

sudo service nginx restart

You can learn more about additional NGINX setting from quite a load of tutorials.