Raymond Gan rayning0

Community

Elixir Slack Group

Cheatsheets

GenServer Cheatsheet by Benjamin Tan Wei Hao

Books

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

First of all, please note that token expiration and revoking are two different things.

Expiration only happens for web apps, not for native mobile apps, because native apps never expire.
Revoking only happens when (1) uses click the logout button on the website or native Apps;(2) users reset their passwords; (3) users revoke their tokens explicitly in the administration panel.

1. How to hadle JWT expiration

A JWT token that never expires is dangerous if the token is stolen then someone can always access the user's data.

Quoted from JWT RFC:

Project Title

One Paragraph of project description goes here

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes. See deployment for notes on how to deploy the project on a live system.

Prerequisites

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:

Direct links to free Springer maths books (pdf versions)

duplicates = multiple editions

A Classical Introduction to Modern Number Theory,Kenneth IrelandMichael Rosen

A Course in Arithmetic,Jean-Pierre Serre

Normal

Level	Score	Regex	Credit

	# http://www.rubyinside.com/does-the-gil-make-your-ruby-code-thread-safe-6051.html

	class Sheep
	def initialize
	@shorn = false

	# Here the sheep owns the mutex. But now the
	# shearing logic is muddied up by synchronization
	# logic. This doesn't seem like the right place for
	# this.

	So i was using Rails 4.1 with Unicorn v4.8.2 and when i tried to deploy my app it doesn't start properly and into the unicorn.log file i found this error message:

	"app error: Missing `secret_key_base` for 'production' environment, set this value in `config/secrets.yml` (RuntimeError)"

	After a little research i found that Rails 4.1 change the way to manage the secret_key, so if we read the secrets.yml file located at exampleRailsProject/config/secrets.yml (you need to replace "exampleRailsProject" for your project name) you will find something like this:

	# Do not keep production secrets in the repository,
	# instead read values from the environment.
	production:
	secret_key_base: <%= ENV["SECRET_KEY_BASE"] %>

	# Author: Pieter Noordhuis
	# Description: Simple demo to showcase Redis PubSub with EventMachine
	#
	# Update 7 Oct 2010:
	# - This example does not appear to work with Chrome >=6.0. Apparently,
	# the WebSocket protocol implementation in the cramp gem does not work
	# well with Chrome's (newer) WebSocket implementation.
	#
	# Requirements:
	# - rubygems: eventmachine, thin, cramp, sinatra, yajl-ruby