Thanh Huynh hkthanh89

Self Signed SSL Certificate for AWS ALB

Generate private key

$> openssl genrsa 2048 > my-private-key.pem

Generate certificate using private key, you will be prompted to fill some fields. Fill required fields randomly, except for Common Name fill it with *.amazonaws.com or your valid domain name

Interview Questions

Node.js

Q1: What do you mean by Asynchronous API? ☆☆

Answer: All APIs of Node.js library are aynchronous that is non-blocking. It essentially means a Node.js based server never waits for a API to return data. Server moves to next API after calling it and a notification mechanism of Events of Node.js helps server to get response from the previous API call.

Source: tutorialspoint.com

FWIW: I didn't produce the content presented here (the outline from Edmond Lau's book). I've just copy-pasted it from somewhere over the Internet, but I cannot remember what exactly the original source is. I was also not able to find the author's name, so I cannot give him/her the proper credits.

Effective Engineer - Notes

By Edmond Lau
Highly Recommended 👍
http://www.theeffectiveengineer.com/

What's an Effective Engineer?

This guide assumes that you recently run brew upgrade postgresql and discovered to your dismay that you accidentally bumped from one major version to another: say 9.3.x to 9.4.x. Yes, that is a major version bump in PG land.

First let's check something.

brew info postgresql

The top of what gets printed as a result is the most important:

DigitalOcean Ubuntu 14.04 x64 + Rails 4 + Nginx + Unicorn + PostgreSQL + Capistrano 3

Create a Droplet

SSH into Root

$ ssh root@123.123.123.123

Change Root Password

	class Banner < ActiveRecord::Base
	attr_accessor :image_width, :image_height
	mount_uploader :image, ImageUploader

	validate :check_dimensions, :on => :create
	def check_dimensions
	if !image_cache.nil? && (image.width < 300 \|\| image.height < 300)
	errors.add :image, "Dimension too small."
	end
	end

	# encoding: utf-8

	class AvatarUploader < CarrierWave::Uploader::Base

	include CarrierWave::MiniMagick

	# Choose what kind of storage to use for this uploader:
	storage :file

	# Override the directory where uploaded files will be stored.

	/**
	* Responsive mixin. The media breakpoints are as defined
	* in the twitter bootstrap framework:
	*
	* - phone
	* - tablet-portrait
	* - tablet-landscape-desktop
	* - large-desktop
	*
	* Additional parameters for tagetting retina and non-retina

	#!/bin/bash
	# from here: http://www.codingsteps.com/install-redis-2-6-on-amazon-ec2-linux-ami-or-centos/
	# and here: https://raw.github.com/gist/257849/9f1e627e0b7dbe68882fa2b7bdb1b2b263522004/redis-server
	###############################################
	# To use:
	# wget https://raw.github.com/gist/2776679/04ca3bbb9f085b192f6aca945120fe12d59f15f9/install-redis.sh
	# chmod 777 install-redis.sh
	# ./install-redis.sh
	###############################################
	echo "*****************************************"

	:80 {
	root /serve
	}