Jason H JaosnHsieh

Typing vagrant from the command line will display a list of all available commands.

Be sure that you are in the same directory as the Vagrantfile when running these commands!

Creating a VM

vagrant init -- Initialize Vagrant with a Vagrantfile and ./.vagrant directory, using no specified base image. Before you can do vagrant up, you'll need to specify a base image in the Vagrantfile.
vagrant init <boxpath> -- Initialize Vagrant with a specific box. To find a box, go to the public Vagrant box catalog. When you find one you like, just replace it's name with boxpath. For example, vagrant init ubuntu/trusty64.

Starting a VM

vagrant up -- starts vagrant environment (also provisions only on the FIRST vagrant up)

WebRTC on LAN

剛嘗試了怎麼樣在區域網路中使用 WebRTC 來進行 VOIP，意外發現其實滿簡單的。分享一下我的步驟

P.S 這是提供給外部網路不通的環境下，如果外部網路通暢，那麼可以直接用現有服務，如 https://talky.io/ 即可

架起 WebRTC Signal Server

git clone https://github.com/andyet/signalmaster

Installing SSHPASS

SSHPass is a tiny utility, which allows you to provide the ssh password without using the prompt. This will very helpful for scripting. SSHPass is not good to use in multi-user environment. If you use SSHPass on your development machine, it don't do anything evil.

Installing on Ubuntu

apt-get install sshpass

	package main

	import (
	"flag"
	"io"
	"log"
	"net"
	"net/http"
	"strings"
	)

	// https://codepen.io/hartzis/pen/VvNGZP
	class ImageUpload extends Component {
	constructor(props) {
	super(props);
	this.state = {
	file: '',
	imagePreviewUrl: ''
	};
	this._handleImageChange = this._handleImageChange.bind(this);
	this._handleSubmit = this._handleSubmit.bind(this);

	var a = ["sdfdf", "http://oooooolol"],
	handleNetErr = function(e) { return e };

	Promise.all(fetch('sdfdsf').catch(handleNetErr), fetch('http://invalidurl').catch(handleNetErr))
	.then(function(sdf, invalid) {
	console.log(sdf, invalid) // [Response, TypeError]
	})
	.catch(function(err) {
	console.log(err);
	})

	var express = require('express');
	var cookieParser = require('cookie-parser');
	var session = require('express-session');
	var flash = require('express-flash');
	var handlebars = require('express-handlebars')

	var app = express();
	var sessionStore = new session.MemoryStore;

	// View Engines

	# Change YOUR_TOKEN to your prerender token
	# Change example.com (server_name) to your website url
	# Change /path/to/your/root to the correct value

	server {
	listen 80;
	server_name example.com;

	root /path/to/your/root;
	index index.html;

	var sqrt = function(x) {
	var isGoodEnough = function(guess) {
	return Math.abs(guess * guess - x) / x < 0.001;
	};

	var improve = function(guess) {
	return (guess + x / guess) / 2;
	};

	var sqrIter = function(guess) {