Hasith Senevirathne hasithsen

On the host

Ensure these modules are loaded

cat /proc/sys/net/bridge/bridge-nf-call-iptables

Disable swap

sysctl vm.swappiness=0
swapoff -a

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?

Make Sandstorm and other web server coexist in the same port while keeping HTTPS encryption.

Introduction

The purpose of this tutorial is to set up SNI Proxy so it’s possible to use Sandstorm verified SSL encryption while coexisting with another web server that also uses SSL.

The main reason is to allow other users to connect with your Sandstorm instance in the standard HTTPS port (443) and keep using that port also for any other web apps.

VirtualBox Host-Only Static IP

My typical setup for a development box in VirtualBox uses two NICs. The first uses NAT to allow the box to communicate with the outside world through my host computer’s network connection. (NAT is the default, so shouldn't require any setup.) The second is a "host-only" connection that allows my host and guest to interact.

To create a host-only connection in VirtualBox, start by opening the preferences in VirtualBox. Go to the "Network" tab, and addd a Host-only Network. Modify the host-only network, and disable DHCP. Make a note of the IP address. (Feel free to set the IP address as well, if you like.)

Next, assign this host-only adapter to the virtual machine. Select the VM and press "Settings". Go to the "Network" tab, and select "Adpater 2". Enable the adapter, set it to a "Host-only Adapter", and select the adpater you created above.

	function enableContextMenu(aggressive = true) {
	void (document.ondragstart = null);
	void (document.onselectstart = null);
	void (document.onclick = null);
	void (document.onmousedown = null);
	void (document.onmouseup = null);
	void (document.body.oncontextmenu = null);
	enableRightClickLight(document);
	if (aggressive) {
	enableRightClick(document);

	$startTime = date("Y-m-d H:i:s");

	//display the starting time
	echo 'Starting Time: '.$startTime;

	//add 1 hour to time
	$cenvertedTime = date('Y-m-d H:i:s',strtotime('+1 hour',strtotime($startTime)));

	//display the converted time
	echo 'Converted Time (added 1 hour): '.$cenvertedTime;

	# Install chromedriver from https://sites.google.com/a/chromium.org/chromedriver/downloads

	import os

	from optparse import OptionParser

	from selenium import webdriver
	from selenium.webdriver.chrome.options import Options

	CHROME_PATH = '/usr/bin/google-chrome'

	<!-- Example #1 - no styling -->
	Made with ❤ in Switzerland
	Made with ♥ in Switzerland
	Made with ♡ in Switzerland
	Made with ❤️ in Switzerland
	Made with ♥️ in Switzerland

	<!-- Example #2 - inline-styled ❤ -->
	Made with <span style="color: #e25555;">♥</span> in Switzerland
	Made with <span style="color: #e25555;">&hearts;</span> in Switzerland

	#################################################################
	# = This script transfers bash history to zsh history
	# = Change bash and zsh history files, if you don't use defaults
	#
	# = Usage: ruby bash_to_zsh_history.rb
	#
	# = Author: Ankit Goyal
	#################################################################

	# change if you don't use default values

	from django import forms
	from django.core import validators
	from django.core.exceptions import ValidationError

	class MinLengthValidator(validators.MinLengthValidator):
	message = 'Ensure this value has at least %(limit_value)d elements (it has %(show_value)d).'

	class MaxLengthValidator(validators.MaxLengthValidator):
	message = 'Ensure this value has at most %(limit_value)d elements (it has %(show_value)d).'