grvgr

WireGuard Site-to-Site

Accessing a subnet that is behind a WireGuard client using a site-to-site setup

Problem Summary

We want to access a local subnet remotely, but it is behind a NAT firewall and we can't setup port forwarding. Outgoing connections work, but all incoming connections get DROPPED by the ISP's routing policy.

Solution Summary

grvgr

Resources: 
http://code.google.com/p/dragonfly
http://sourceforge.net/projects/natlink/
http://tech.groups.yahoo.com/group/VoiceCoder/

Inspirations:
http://emacs-vr-mode.sourceforge.net/
http://sourceforge.net/projects/voicecode/
and especially http://shorttalk-emacs.sourceforge.net/ShortTalk/index.html from which I've stolen a few key ideas and utterances.

grvgr

# Reliable persistent SSH-Tunnel via systemd (not autossh)
# https://gist.github.com/guettli/31242c61f00e365bbf5ed08d09cdc006#file-ssh-tunnel-service

[Unit]
Description=Tunnel for %i
After=network.target

[Service]
User=tunnel
ExecStart=/usr/bin/ssh -o "ExitOnForwardFailure yes" -o "ServerAliveInterval 60" -N tunnel@%i

grvgr

OS X Preferences

---

most of these require logout/restart to take effect

# Enable character repeat on keydown
defaults write -g ApplePressAndHoldEnabled -bool false

# Set a shorter Delay until key repeat

grvgr

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

grvgr

(deftheme bubbleberry "bubbleberry")

;; Based on the theme used for LightTable (see: http://www.chris-granger.com/images/lightable/main.png )

(custom-theme-set-variables
 'bubbleberry
 '(linum-format " %7i ")
 '(fringe-mode 5 nil (fringe))
 '(powerline-color1 "#3d3d68")
 '(powerline-color2 "#292945")

grvgr

#!/usr/bin/env ruby

# This script is intended to preprocess a knife ec2 server create command and 
# generate a user_data script in the /tmp folder that will rename the host
# to match whatever the node name is before the chef bootstrapping process
# begins.  It then splits the knife command in front of the --node-name or -N
# options and inserts "--user-data /tmp/server-01.userdata" (in the example 
# below) and execs the command.
# 
# Usage:

grvgr

require 'yaml'
require 'uri'
require 'tempfile'
require 'tmpdir'

SDK_DIR = "/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.3.sdk"
TESTFLIGHT_URL = 'http://testflightapp.com/api/builds.json'

PROJECT_DIR = File.dirname __FILE__
RUBIOS_DIR = File.join(PROJECT_DIR, 'rubios')

grvgr

#!/bin/bash

# https://gist.github.com/949831
# http://blog.carbonfive.com/2011/05/04/automated-ad-hoc-builds-using-xcode-4/

# command line OTA distribution references and examples
# http://nachbaur.com/blog/how-to-automate-your-iphone-app-builds-with-hudson
# http://nachbaur.com/blog/building-ios-apps-for-over-the-air-adhoc-distribution
# http://blog.octo.com/en/automating-over-the-air-deployment-for-iphone/
# http://www.neat.io/posts/2010/10/27/automated-ota-ios-app-distribution.html

grvgr

# USAGE: Hash.from_xml:(YOUR_XML_STRING)
require 'nokogiri'
# modified from http://stackoverflow.com/questions/1230741/convert-a-nokogiri-document-to-a-ruby-hash/1231297#1231297

class Hash
  class << self
    def from_xml(xml_io) 
      begin
        result = Nokogiri::XML(xml_io)
        return { result.root.name.to_sym => xml_node_to_hash(result.root)}