Daniel Liu lgh06

Git Compression of Blobs and Packfiles.

Many users of Git are curious about the lack of delta compression at the object (blob) level when commits are first written. This efficiency is saved until the pack file is written. Loose objects are written in compressed, but non-delta format at the time of each commit.

A simple run though of a commit sequence with only the smallest change to the image (in uncompressed TIFF format to amplify the observable behavior) aids the understanding of this deferred and different approach efficiency.

The command sequence:

Create the repo:

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

Routing tips for VPNs on OS X

When VPNs Just Work™, they're a fantastic way of allowing access to a private network from remote locations. When they don't work it can be an experience in frustration. I've had situations where I can connect to a VPN from my Mac, but various networking situations cause routing conflicts. Here are a couple of cases and how I've been able to get around them.

Specific cases

Case 1: conflicting additional routes.

In this example the VPN we are connecting to has a subnet that does not conflict with our local IP, but has additional routes that conflict in some way with our local network's routing. In my example the remote subnet is 10.0.x.0/24, my local subnet is 10.0.y.0/24, and the conflicting route is 10.0.0.0/8. Without the later route, I can't access all hosts on the VPN without manually adding the route after connecting to the VPN:

#Linux - Running a Node Service (Forever) This is based on the excellent post at http://www.exratione.com/2013/02/nodejs-and-forever-as-a-service-simple-upstart-and-init-scripts-for-ubuntu/.

Forever is a useful tool for running a Node.js process with monitoring; it can be set to restart a failed process, and has a few other helpful features along the same lines. In this post you'll find a couple of exceedingly simple scripts for running a Node.js process as a service on Ubuntu using Forever.

##Install Forever Forever must be installed globally.

npm -g install forever

#Meteor and Self-hosted Infrastructure

Meteor is an eye-opening JavaScript framework that runs on both the client and the server, giving developers a revolutionary take on software engineering. If you are not familiar with Meteor, I urge you to visit their website.

##An overview

In this brief gist, I am going to discuss the process of setting up a server (in my case, a VPS) to host Meteor applications.

My experience with Meteor has been brief, however it has not taken much demonstration for me to realise the significance of this stellar framework. Let's jump right in!

	/* JSON-Websocket-AMQP bridge */


	var amqp_ws = function() {

	ws = null;
	function recieve_amqp(args) {
	console.log(args.msg);
	};

	#!/bin/bash

	# This way you can customize which branches should be skipped when
	# prepending commit message.
	if [ -z "$BRANCHES_TO_SKIP" ]; then
	BRANCHES_TO_SKIP=(master develop test)
	fi

	BRANCH_NAME=$(git symbolic-ref --short HEAD)
	BRANCH_NAME="${BRANCH_NAME##*/}"

	0. SSH to server
	1. Edit /opt/bitnami/apps/jenkins/jenkins_home/config.xml

	2. set userSecurity to false: <userSecurity>false</userSecurity>

	3. delete
	<authorizationStrategy> and <securityRealm>

	4. /etc/init.d/bitnami restart

	var mongoose = require('mongoose')
	var mongoUrl = "mongodb://localhost:27017/test"

	var connectWithRetry = function() {
	return mongoose.connect(mongoUrl, function(err) {
	if (err) {
	console.error('Failed to connect to mongo on startup - retrying in 5 sec', err);
	setTimeout(connectWithRetry, 5000);
	}
	});

	{url:'stun:stun01.sipphone.com'},
	{url:'stun:stun.ekiga.net'},
	{url:'stun:stun.fwdnet.net'},
	{url:'stun:stun.ideasip.com'},
	{url:'stun:stun.iptel.org'},
	{url:'stun:stun.rixtelecom.se'},
	{url:'stun:stun.schlund.de'},
	{url:'stun:stun.l.google.com:19302'},
	{url:'stun:stun1.l.google.com:19302'},
	{url:'stun:stun2.l.google.com:19302'},