Jonas Porto jonasporto

Not all random values are created equal - for security-related code, you need a specific kind of random value.

A summary of this article, if you don't want to read the entire thing:

Don't use Math.random(). There are extremely few cases where Math.random() is the right answer. Don't use it, unless you've read this entire article, and determined that it's necessary for your case.
Don't use crypto.getRandomBytes directly. While it's a CSPRNG, it's easy to bias the result when 'transforming' it, such that the output becomes more predictable.
If you want to generate random tokens or API keys: Use uuid, specifically the uuid.v4() method. Avoid node-uuid - it's not the same package, and doesn't produce reliably secure random values.
If you want to generate random numbers in a range: Use random-number-csprng.

You should seriously consider reading the entire article, though - it's

Install node-repl-promised: npm install -g repl-promised

Use the repl to list all users

$ node-promised
> var app = require('./app');
undefined
> var Bookshelf = app.get('bookshelf');
undefined

⇐ back to the gist-blog at jrw.fi

Advanced SCSS

Or, 16 cool things you may not have known your stylesheets could do. I'd rather have kept it to a nice round number like 10, but they just kept coming. Sorry.

I've been using SCSS/SASS for most of my styling work since 2009, and I'm a huge fan of Compass (by the great @chriseppstein). It really helped many of us through the darkest cross-browser crap. Even though browsers are increasingly playing nice with CSS, another problem has become very topical: managing the complexity in stylesheets as our in-browser apps get larger and larger. SCSS is an indispensable tool for dealing with this.

This isn't an introduction to the language by a long shot; many things probably won't make sense unless you have some SCSS under your belt already. That said, if you're not yet comfy with the basics, check out the aweso

Rails Migration

http://guides.rubyonrails.org/migrations.html

Migrations methods:

add_column
add_index
change_column
change_table
create_table
drop_table

On Tue Oct 27, 2015, history.state.gov began buckling under load, intermittently issuing 500 errors. Nginx's error log was sprinkled with the following errors:

2015/10/27 21:48:36 [crit] 2475#0: accept4() failed (24: Too many open files) 2015/10/27 21:48:36 [alert] 2475#0: *7163915 socket() failed (24: Too many open files) while connecting to upstream...

An article at http://www.cyberciti.biz/faq/linux-unix-nginx-too-many-open-files/ provided directions that mostly worked. Below are the steps we followed. The steps that diverged from the article's directions are marked with an *.

- Instead of using su to run ulimit on the nginx account, use ps aux | grep nginx to locate nginx's process IDs. Then query each process's file handle limits using cat /proc/pid/limits (where pid is the process id retrieved from ps). (Note: sudo may be necessary on your system for the cat command here, depending on your system.)
Added fs.file-max = 70000 to /etc/sysctl.conf
Added `nginx soft nofile 1

	#Model

	@user.should have(1).error_on(:username) # Checks whether there is an error in username
	@user.errors[:username].should include("can't be blank") # check for the error message

	#Rendering
	response.should render_template(:index)

	#Redirecting
	response.should redirect_to(movies_path)

	#!/bin/sh

	# script for optimizing images in a directory (recursive)
	# pngcrush & jpegtran settings from:
	# http://developer.yahoo.com/performance/rules.html#opt_images

	# pngcrush
	for png in `find $1 -iname "*.png"`; do
	echo "crushing $png ..."
	pngcrush -rem alla -reduce -brute "$png" temp.png

	window.analyzer = {
	init: function (object, id) {
	this.functions.appendTable(id);
	this.functions.setupHeaders(object);
	this.functions.addData(object);
	this.functions.addCaption("Analysis of the stylesheets");
	},
	data: {},
	helpers: {
	wrapper: function (id) {

	supervisord [supervisord.org]
	=============================

	* Set up jobs via a config file (.ini style)

	Example:
	--------
	[program:forever]
	command=/usr/bin/python /root/supervisoreval/bin/forever.py &
	numprocs=1