carlware

require 'redis'
require 'securerandom'
require 'msgpack'

class RedisRpcClient

  def initialize(redis_url, list_name)
    @client = Redis.connect(url: redis_url)
    @list_name = list_name.to_s
  end

carlware

#!/bin/bash
#
# Bash script to setup headless Selenium (uses Xvfb and Chrome)
# (Tested on Ubuntu 12.04) trying on ubuntu server 14.04

# Add Google Chrome's repo to sources.list
echo "deb http://dl.google.com/linux/chrome/deb/ stable main" | sudo tee -a /etc/apt/sources.list

# Install Google's public key used for signing packages (e.g. Chrome)
# (Source: http://www.google.com/linuxrepositories/)

carlware

A few show tricks to find slow queries in mongodb

Enable profiling

First, you have to enable profiling

> db.setProfilingLevel(1)

Now let it run for a while. It collects the slow queries ( > 100ms) into a capped collections, so queries go in and if it's full, old queries go out, so don't be surprised that it's a moving target...

carlware

Toc

Keyboard shortcuts

The IPython Notebook has two different keyboard input modes. Edit mode allows you to type code/text into a cell and is indicated by a green cell border. Command mode binds the keyboard to notebook level actions and is indicated by a grey cell border.

MacOS modifier keys:

• ⌘ : Command

carlware

import pyproj
from shapely.geometry import shape
from shapely.ops import transform

geom = {'type': 'Polygon',
        'coordinates': [[[-122., 37.], [-125., 37.],
	                     [-125., 38.], [-122., 38.],
                         [-122., 37.]]]}

s = shape(geom)

carlware

Apache Spark installation + ipython notebook integration guide for Mac OS X

Tested with Apache Spark 1.3.1, Python 2.7.9 and Java 1.8.0_45 + workaround for Spark 1.4.x from @enahwe.

Install Java Development Kit

Download and install it from oracle.com

carlware

OS X Screencast to animated GIF

This gist shows how to create a GIF screencast using only free OS X tools: QuickTime, ffmpeg, and gifsicle.

Instructions

To capture the video (filesize: 19MB), using the free "QuickTime Player" application:

carlware

# Ask for the user password
# Script only works if sudo caches the password for a few minutes
sudo true

# Install kernel extra's to enable docker aufs support
sudo apt-get -y install linux-image-extra-$(uname -r)

# Add Docker PPA and install latest version
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 36A1D7869245C8950F966E92D8576A8BA88D21E9
sudo sh -c "echo deb https://get.docker.io/ubuntu docker main > /etc/apt/sources.list.d/docker.list"

carlware

#
# Slightly tighter CORS config for nginx
#
# A modification of https://gist.github.com/1064640/ to include a white-list of URLs
#
# Despite the W3C guidance suggesting that a list of origins can be passed as part of
# Access-Control-Allow-Origin headers, several browsers (well, at least Firefox) 
# don't seem to play nicely with this.
#

carlware

#
# Wide-open CORS config for nginx
#
location / {

     if ($request_method = 'OPTIONS') {

        add_header 'Access-Control-Allow-Origin' '*';
        
        #