ekreutz

Ansible variable precedence

Source: http://docs.ansible.com/ansible/latest/playbooks_variables.html#variable-precedence-where-should-i-put-a-variable

From least to most important

• command line values (for example, -u my_user, these are not variables)
• role defaults (defined in role/defaults/main.yml)
• inventory file or script group vars
• inventory group_vars/all

lelandbatey

Description

This simple script will take a picture of a whiteboard and use parts of the ImageMagick library with sane defaults to clean it up tremendously.

The script is here:

#!/bin/bash
convert "$1" -morphology Convolve DoG:15,100,0 -negate -normalize -blur 0x1 -channel RBG -level 60%,91%,0.1 "$2"

Results

jfarmer

true and false vs. "truthy" and "falsey" (or "falsy") in Ruby, Python, and JavaScript

Many programming languages, including Ruby, have native boolean (true and false) data types. In Ruby they're called true and false. In Python, for example, they're written as True and False. But oftentimes we want to use a non-boolean value (integers, strings, arrays, etc.) in a boolean context (if statement, &&, ||, etc.).

This outlines how this works in Ruby, with some basic examples from Python and JavaScript, too. The idea is much more general than any of these specific languages, though. It's really a question of how the people designing a programming language wants booleans and conditionals to work.

If you want to use or share this material, please see the license file, below.

Update

kyledrake

# The blog post that started it all: https://neocities.org/blog/the-fcc-is-now-rate-limited
#
# Current known FCC address ranges:
# https://news.ycombinator.com/item?id=7716915
#
# Confirm/locate FCC IP ranges with this: http://whois.arin.net/rest/net/NET-165-135-0-0-1/pft
#
# In your nginx.conf:

location / {

jchandra74

Pimping Up Your PowerShell & Cmder with Posh-Git, Oh-My-Posh, & Powerline Fonts

Backstory (TLDR)

I work as a full-stack developer at work. We are a Windows & Azure shop, so we are using Windows as our development platform, hence this customization.

For my console needs, I am using Cmder which is based on ConEmu with PowerShell as my shell of choice.

Yes, yes, I know nowadays you can use the Linux subsystem on Windows 10 which allow you to run Ubuntu on Windows. If you are looking for customization of the Ubuntu bash shell, check out this article by Scott Hanselman.

acolyer

Internet Scale Services Checklist

A checklist for designing and developing internet scale services, inspired by James Hamilton's 2007 paper "On Desgining and Deploying Internet-Scale Services."

• http://mvdirona.com/jrh/talksandpapers/jamesrh_lisa.pdf

Basic tenets

• Does the design expect failures to happen regularly and handle them gracefully?
• Have we kept things as simple as possible?

lamont-granquist

This has been moved into the official Chef docs:

https://docs.chef.io/custom_resources_notes.html

12.5 style custom resources

This is by far the most recommended way of writing resources for all users. There are two gotchas which we're working through:

1. For helper functions that you used to write in your provider code or used to mixin to your provider code, you have to use an action_class do ... end block.

kwilczynski

If you want to check whether a node run_list includes a specific role (upon expansion), then you could use role? method on the Node object:

node.role?('name')

Alternatively, you can see whether either would work for you:

node.roles.include?('name')

node.run_list?('role[name]')

fnichol

Auto-enable Local HTTP Caching in Test Kitchen

Note: total experiment and hack, looks nasty, could be awesome:

Setup

• Drop the kitchen.local.yml into $HOME/.kitchen/config.yml
• Install polipo (with Mac: brew install polipo, with Ubuntu: apt-get install polipo)
• Drop polipo-start and polipo-console somewhere useful (perhaps $HOME/bin?)

naesheim

##################
### config.yml ###
##################

version: 2
jobs:
    build:
        docker:
            - image: circleci/python:3.6
        steps: