Andrew Kane ankane

Ideal Postgres environment

Documentation

Documented replication topology
Documented network topology
Documented interface topology - including users, passwords, connection estimates, load balancers, connection proxies
Documented procedure, schedule for failover and testing
Documented procedure, schedule for disaster recovery and testing

Opening and closing an SSH tunnel in a shell script the smart way

I recently had the following problem:

From an unattended shell script (called by Jenkins), run a command-line tool that accesses the MySQL database on another host.
That tool doesn't know that the database is on another host, plus the MySQL port on that host is firewalled and not accessible from other machines.

We didn't want to open the MySQL port to the network, but it's possible to SSH from the Jenkins machine to the MySQL machine. So, basically you would do something like

ssh -L 3306:localhost:3306 remotehost

Deploy Rails 4 app with Dokku on DigitalOcean

Install dokku

First create a Ubuntu 13.04 x64 droplet on DigitalOcean Control Panel

Then ssh with root account, run this in termianl:

$ wget -qO- https://raw.github.com/progrium/dokku/master/bootstrap.sh | sudo bash

How to set up stress-free SSL on an OS X development machine

One of the best ways to reduce complexity (read: stress) in web development is to minimize the differences between your development and production environments. After being frustrated by attempts to unify the approach to SSL on my local machine and in production, I searched for a workflow that would make the protocol invisible to me between all environments.

Most workflows make the following compromises:

Use HTTPS in production but HTTP locally. This is annoying because it makes the environments inconsistent, and the protocol choices leak up into the stack. For example, your web application needs to understand the underlying protocol when using the secure flag for cookies. If you don't get this right, your HTTP development server won't be able to read the cookies it writes, or worse, your HTTPS production server could pass sensitive cookies over an insecure connection.
Use production SSL certificates locally. This is annoying

	#!/bin/bash

	# Check out the blog post at:
	#
	# http://www.philipotoole.com/influxdb-and-grafana-howto
	#
	# for full details on how to use this script.

	AWS_EC2_HOSTNAME_URL=http://169.254.169.254/latest/meta-data/public-hostname
	INFLUXDB_DATABASE=test1

	# http://www.evanmiller.org/bayesian-ab-testing.html implemented in ruby
	# requires the distribution gem from https://github.com/clbustos/distribution (gem 'distribution', require: false)

	def probability_b_beats_a(completed_a, total_a, completed_b, total_b)
	require 'distribution/math_extension'
	total = 0.0

	alpha_a = completed_a + 1
	beta_a = total_a - completed_a + 1
	alpha_b = completed_b + 1

	#!/usr/bin/env python2
	"""
	Author: takeshix <[email protected]>
	PoC code for CVE-2014-0160. Original PoC by Jared Stafford ([email protected]).

	Supportes all versions of TLS and has STARTTLS support for SMTP,POP3,IMAP,FTP and XMPP.
	"""

	import sys,struct,socket
	from argparse import ArgumentParser

	WITH btree_index_atts AS (
	SELECT nspname, relname, reltuples, relpages, indrelid, relam,
	regexp_split_to_table(indkey::text, ' ')::smallint AS attnum,
	indexrelid as index_oid
	FROM pg_index
	JOIN pg_class ON pg_class.oid=pg_index.indexrelid
	JOIN pg_namespace ON pg_namespace.oid = pg_class.relnamespace
	JOIN pg_am ON pg_class.relam = pg_am.oid
	WHERE pg_am.amname = 'btree'
	),

	from matplotlib import use

	from pylab import *
	from scipy.stats import beta, norm, uniform
	from random import random
	from numpy import *
	import numpy as np
	import os

	# Input data

	import matplotlib
	matplotlib.use("WXAgg")
	from pylab import *
	from scipy.stats import beta, uniform, norm

	class BetaBandit(object):
	def __init__(self, num_options=2, prior=(1.0,1.0)):
	self.trials = zeros(shape=(num_options,), dtype=int)
	self.successes = zeros(shape=(num_options,), dtype=int)
	self.num_options = num_options