My favourite quotes from the book Legion: Skin deep by Brandon Sanderson:

Always tell your captives they have more time than they do. It makes them relaxed. Sets them to planning instead of trying to break out immediately. The last thing you want to do is to make them desperate, since desperate people are unpredictable.

Anything that is possible is actually a reality given infinity.

Post from James Clear here: http://jamesclear.com/better-sleep

In the words of the researchers, sleep debt “has a neurobiological cost which accumulates over time.” After one week, 25 percent of the six-hour group was falling asleep at random times throughout the day. After two weeks, the six-hour group had performance deficits that were the same as if they had stayed up for two days straight. Let me repeat that: if you get 6 hours of sleep per night for two weeks straight, your mental and physical performance declines to the same level as if you had stayed awake for 48 hours straight.

The irony of it all is that many of us are suffering from sleep deprivation so that we can work more, but the drop in performance ruins any potential benefits of working additional hours.

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 wondered about basically the same quesiton as user 7cows had: In what cases should one prefer to use Node.js only as a server in real deployment? When one does not want to use Node.js only, what plays better with Node.js, Apache or Nginx?

The answer, by pauljz, was:

There are several good reasons to stick another webserver in front of Node.js:

• 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.
• As Matt Sergeant mentioned in his answer, you can 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.

I’ll caveat the second bullet point by saying you should probably be serving your static files via a CDN, or from behind a caching server like Varnish. If you’re doing this it doesn’t really matter if the origin is Node or Nginx or Apache.

Caveat with nginx specifically: if you’re using websockets, make sure to use a recent version of nginx (>= 1.3.13), since it only just added support for upgrading a connection to use websockets.

Also, user Matt Sergeant added:

Just to add one more reason to pauljz’s answer, I use a front end server so that it can serve up 502 error pages when I’m restarting the backend server or it crashes for some reason. This allows your users to never get an error about unable to establish a connection.

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 quesiton was:

I have an input field which once filled with a number populates that count of additional input fields. I can’t figure out how to get the values inserted in those generated input fields. Any help is appreciated, and oh, I did try various things and even with angular.element, or solely with jquery, but failed, so any explanation on how to do this is welcome.

Here is my jsfiddle, and the code c/p-ed here:

<div ng-controller="MyCtrl">
    <input type="text" ng-model="cntInputs" placeholder="#Inputs"><br/>

    <input ng-repeat="i in getTimes()" type="text" placeholder="{{i}}" id="input_{{i}}">

    <ul>
        <li ng-repeat="j in getTimes()">
            Inputed value is: {{getValue(j)}}
        </li>
    </ul>
</div>

js:

var myApp = angular.module('myApp', []);


function MyCtrl($scope) {
    $scope.cntInputs = 0;

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

        for(var i=1; i <= $scope.cntInputs; i++)
            a.push(i);

        return a;       
    };

    $scope.getValue = function(id){
        //here get the value of that inserted in the element with the id of "input_" + id
        return angular.element("input_" + id);
    }
}

The answer, by James Kleeh, was:

So add ng-model="inputs[i-1]" to your text field

Then in your controller add $scope.inputs= [];

Then in your getValue function: return $scope.inputs[id-1];

If you make your getTimes function 0 based you wouldn’t need the -1s

Updated your fiddle: http://jsfiddle.net/7MhLd/60/

The only quote I liked from the book Storm Front by Jim Butcher:

I made a vampire cry. I felt like a real super hero now. Harry Blackstone Copperfield Dresden, breaker of monster’s hearts.

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 quesiton was:

I am using this webkitdotnet in my C# project. It all went well until I had to use access site with https.

I’ve searched their forum and found few posts about this but none of it solves my problem, so please shed some light on this one. Thx!

edit: Also as mentioned in their threads (also without an answer) I get a “Peer certificate cannot be authenticated with known CA certificates” error when trying to access my server, buthttps://www.google.com works fine.

They also mention the “apple” build which worked fine with ssl (at least so they say), but I can’t find it anywhere…

The answer, by therealmitchconnors, was:

This is a bit of a hack, but you can make webkitdotnet ingore peer ssl errors. WebKitDotNet uses WebKit, which, in turn uses curl, which is responsible for your wonderful ssl error there. curl exposes an option to ignore ssl errors, but neither webkit nor webkitdotnet seem to expose this functionality in their api. However, if you checkout the webkit source code, webkit sets the curl option (CURLOPT_SSL_VERIFYPEER) to false if the value of the environment variable WEBKIT_IGNORE_SSL_ERRORS is set to true.

What this all boils down to is that if you set the environment variable in code before initializing either webkit or webkitdotnet components, webkit will ignore the bad certificate and allow you to navigate to the site (sort of like clicking Proceed Anyway on IE9’s Bad Certificate Warning page).

C++:

setvar("WEBKIT_IGNORE_SSL_ERRORS", "1");

C#:

Environment.SetEnvironmentVariable("WEBKIT_IGNORE_SSL_ERRORS", "1");

If anyone is interested, the webkit source code referenced is in file webkit\Source\WebCore\platform\network\curl\ResourceHandleManager.cpp at lines 65 and 681, currently.

TL;DR: In this short tutorial I’ll show you how I built my own testable (Jasmine) npm module which I then published to npm repository. The npm module is here, and the GitHub repository is here.

First, if you haven’t already, set some author info in your terminal:

npm set init.author.name "Nikola Brežnjak"
npm set init.author.email "[email protected]"
npm set init.author.url “http://www.nikola-breznjak.com"

Then, create a new GitHub repository, clone it to your disk and then run npm init. Create a index.js file and copy/paste the following code:

module.exports = function(){
    return 42;
}

Next, install Jasmine by doing:

npm install jasmine-node -g

To test your module, create a folder spec, and a file TheAnswerToLifeTheUniverseAndEverything.spec.js inside it with the following content:

var TheAnswerToLifeTheUniverseAndEverything = require('../index.js');

describe("TheAnswerToLifeTheUniverseAndEverything Suite", function() {
 it("should return a value of 42", function(done) {
 var value = TheAnswerToLifeTheUniverseAndEverything();
 expect(value).toEqual(42);
 done();
 });
});

In order to test your module, run jasmine-node spec/ as shown on the image below:

In order to publish your npm module you first have to execute the npm adduser command and answer few of the questions, and after that you just have to execute npm publish and you’ll have your npm module listed on npmjs.com:

Now you can use npm install theanswertolifetheuniverseandeverything to install the module.

If you’re testing this your self and you get an error like “Error: forbidden New packages must have all-lowercase names: TheAnswerToLifeTheUniverseAndEverything” then that means what it says – you must use only lowercase letters when naming your modules.

My favourite quotes from the book Scream free parenting by Hal Edward Runkel:

Parenting is not about kids, it’s about parents. The greatest thing you can do for your kids is learn to focus on yourself.

We are responsible for our children – this is the biggest lie. We have responsibility to our children.

To be in charge as a parent means inspiring children to motivate them selves.

The definition of insanity is doing the same thing over and over again expecting a different result.

Then importance of giving your children increasing space as they age is far greater than the fear of what they will do with that space.

It is your room, clean it if you will.

Let them close the door. Knock before you come in, and await their answer and if it’s NO, come back later.

Give them money, but then teach them about it.

Let them struggle.

You can’t? Man, that sucks, what have you tried so far? After the response ask: so what are you going to do about it?

This is what I think, what do you think?

Wow, you’re bored. That stinks. I hate it when I’m bored too. What are you going to do about it?

After 10 minutes in the car – are we there yet? Wow it looks like you really don’t want to be in the car right now. You know what, me neither – and for whole next two hours! What are we going to do about it?

The very act of homework hovering makes a problem even worse.

Learning from our mistakes is the highest form of education possible.

I told you so – don’t use this.

Integrity. It’s very important for your children to believe that what you say is what you honestly believe and what you will actually do.

Broken body makes it extremely difficult to provide for and protect your children. Your health is your first responsibility. Your self-respect is important, as well as your marriage – your marriage is more important than your kids. Take care of yourself in order to benefit others.

The only way to change the pattern is focusing on your part in it, and then do something different. Don’t wait for others to change – you change and the rest will follow.

First things first, if you bought your domain elsewhere then you first need to point that domain to your server. You basically have two options here

• installing, setting up and running a DNS on your VPS and pointing the DNS (from the control panel where you bought a domain) records to your VPS
• setting your DNS Zone file A record (in the control panel where you bought a domain) to the VPS IP
• this posts explain what are the pros and cons

Now, if you do that for multiple domains they will all point to your server’s IP and show the same thing, essentially the thing which is running on port 80 (and that, in our main Nginx installation, will be a default Nginx welcome screen). If you have multiple Node.js applications, which are running on different ports, and you want to pinpoint the domains to that particular applications, then this is where the Nginx comes in so that it takes the requests for each domain and routes it to an appropriate port where the appropriate Node.js application is running. Basically, what Nginx does in this case is called reverse proxying.

Useful links:

• this StackOverflow question
• http://blog.grabeh.net/Digital-Ocean-VPS-Nginx-Express-apps
• https://www.digitalocean.com/community/tutorials/how-to-host-multiple-node-js-applications-on-a-single-vps-with-nginx-forever-and-crontab
• http://ludovf.net/blog/configure-nginx-to-proxy-virtual-hosts-to-apache/
• http://kbeezie.com/apache-with-nginx/
• https://www.digitalocean.com/community/tutorials/how-to-set-up-nginx-virtual-hosts-server-blocks-on-centos-6

Use forever:

• npm install forever -g
• forever start –spinSleepTime 10000 yourApp.js
• if the app crashes, forever starts it up again

Lets start:

• sudo vim /etc/nginx/conf.d/example.com.conf:

  server {
      listen 80;
  
      server_name your-domain.com;
  
      location / {
          proxy_pass http://localhost:{YOUR_PORT};
          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;
      }
  }

• to reference multiple domains for one Node.js app (like www.example.com and example.com) you need to add the following code to the file /etc/nginx/nginx.conf in the http section: server_names_hash_bucket_size 64;
• but, as it always is, the upper statement didn’t work for me, so I ended up using this solution from StackOverflow:

  server {
      #listen 80 is default
      server_name www.example.com;
      return 301 $scheme://example.com$request_uri;
  }

• sudo service nginx restart

Forever keeps your application running when it crashes but if VPS is rebooted it won’t start anymore. Simple cronjob solves this issue. Create starter.sh in your application’s home folder and copy the following code:

#!/bin/sh

if [ $(ps -e -o uid,cmd | grep $UID | grep node | grep -v grep | wc -l | tr -s "\n") -eq 0 ]
then
export PATH=/usr/local/bin:$PATH
forever start --sourceDir /path/to/your/node/app main.js >> /path/to/log.txt 2>&1
fi

where main.js is your application’s main script. Add to crontab the following line: @reboot /path/to/starter.sh.

I’ve been playing with my VPS that I bought from WeLoveServers.net and I previously wrote about how to set up your VPS from scratch. Here I’ll show just brief commands for installing a MEN NPP stack (MongoDB, Express, Node.js, Nginx, PostgreSQL, PHP) on my CentOS machine.

Nginx

• high performance web server that is much more flexible and lightweight than Apache
• SELinux – if you run into issues change the SELinux mode to permissive or disabled
• sudo rpm -Uvh http://nginx.org/packages/centos/7/noarch/RPMS/nginx-release-centos-7-0.el7.ngx.noarch.rpm
• sudo yum install nginx
• sudo systemctl start nginx.service or sudo service nginx start
• sudo systemctl enable nginx.service (no alternative with sudo service)
• default server root directory /usr/share/nginx/html defined /etc/nginx/conf.d/default.conf
• server blocks (known as Virtual Hosts in Apache) are created in /etc/nginx/conf.d. Files that end with .conf in that directory will be loaded when Nginx is started
• main Nginx configuration file is located at /etc/nginx/nginx.conf

• sudo vi /etc/nginx/conf.d/default.conf looks like:

  server {
      listen       80;
      server_name  localhost;
  
      location / {
          root   /usr/share/nginx/html;
          index  index.html index.htm;
      }
      error_page   500 502 503 504  /50x.html;
      location = /50x.html {
          root   /usr/share/nginx/html;
      }
  }

  change to:

  server {
      listen       80;
      server_name  server_domain_name_or_IP;
  
      root   /usr/share/nginx/html;
      index index.php index.html index.htm;
  
      location / {
          try_files $uri $uri/ =404;
      }
      error_page 404 /404.html;
      error_page 500 502 503 504 /50x.html;
      location = /50x.html {
          root /usr/share/nginx/html;
      }
  
      location ~ \.php$ {
          try_files $uri =404;
          fastcgi_pass unix:/var/run/php-fpm/php-fpm.sock;
          fastcgi_index index.php;
          fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
          include fastcgi_params;
      }

• sudo systemctl restart nginx
• sudo nginx -t
  nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
  nginx: configuration file /etc/nginx/nginx.conf test is successful

Node.js

• just a side note for Mac: brew install node
• sudo yum install epel-release
• sudo yum install node
• sudo yum install npm

Express

• npm install express

PHP

• sudo yum install php php-mysql php-fpm
• sudo vi /etc/php.ini – in order to secure it do cgi.fix_pathinfo=0
• sudo vi /etc/php-fpm.d/www.conf set line to listen = /var/run/php-fpm/php-fpm.sock
• sudo systemctl start php-fpm
• sudo systemctl enable php-fpm.service to start from boot

PostgreSQL

• exclude the CentOS version of postgres in order to get the most recent version from the project’s website
• sudo vim /etc/yum.repos.d/CentOS-Base.repo
  At the bottom of the [base] and [updates] sections, add a line that excludes the postgres packages: exclude=postgresql*
• Find the link for your version of the OS here
• curl -O http://yum.postgresql.org/9.4/redhat/rhel-7-x86_64/pgdg-centos94-9.4-1.noarch.rpm
• rpm -ivh pgdg*
• yum list postgres*
• install the -server package: sudo postgresql94-server.x86_64
• sudo /usr/pgsql-9.4/bin/postgresql94-setup initdb
  
• chkconfig postgresql-9.3 on
• service postgresql-9.3 start
• postgres creates a user and a database called postgres
• sudo su – postgres
• psql
• \?: Get a full list of psql commands, including those not listed here
• \h: Get help on SQL commands. You can follow this with a specific command to get help with the syntax
• \q: Quit the psql program and exit to the Linux prompt
• \d: List available tables, views, and sequences in current database
• \du: List available roles
• \dp: List access privileges
• \dt: List tables
• \l: List databases
• \c: Connect to a different database. Follow this by the database name
• \password: Change the password for the username that follows
• \conninfo: Get information about the current database and connection

  CREATE TABLE new_table_name (
      table_column_title TYPE_OF_DATA column_constraints,
      next_column_title TYPE_OF_DATA column_constraints,
      table_constraint
      table_constraint
  ) INHERITS existing_table_to_inherit_from;

   

MongoDB

• Instructions from here
• sudo vim /etc/yum.repos.d/mongodb.repo:

  [mongodb]
  name=MongoDB Repository
  baseurl=http://downloads-distro.mongodb.org/repo/redhat/os/x86_64/
  gpgcheck=0
  enabled=1

• sudo yum install -y mongodb-org
• to prevent unintended upgrades, add to /etc/yum.conf file:
  exclude=mongodb-org,mongodb-org-server,mongodb-org-shell,mongodb-org-mongos,mongodb-org-tools
• sudo service mongod start
• sudo chkconfig mongod on