majackson

Django Migrations without Downtime

The following instructions describe a set of processes allowing you to run Django database migrations against a production database without having to bring the web service down.

Note that in the below instructions, migrations are all run manually at explicit points, and are not an automatic part of the deployment process.

Adding Fields or Tables

Adding a (nullable) field or a new table

1. Make the model or column addition in your code.

appeltel

import asyncio
import random


class Hub():

    def __init__(self):
        self.subscriptions = set()

    def publish(self, message):

r3m0t

# coding: utf-8
"""Cause git to detect a merge conflict when two branches have migrations."""
# myapp/management/commands/makemigrations.py
# you'll need myapp/management/commands/__init__.py and myapp/management/__init__.py in PY2, see Django docs
from __future__ import absolute_import, unicode_literals

import io

import os
import six

ivlevdenis

from graphene import relay, String, List
from graphene_django.filter import DjangoFilterConnectionField
from graphene_django.fields import DjangoConnectionField

from app.models import Model


class Object(DjangoObjectType):
    class Meta:
        model = Model

danwhitston

This is a rough guide to setting up browser testing through Selenium on Windows Subsystem for Linux (WSL), aka Bash on Ubuntu on Windows. It assumes the following environment:

• Windows 10, running WSL
• A Ruby dev environment, running inside WSL
• Code that we want to test using a web driver, in this case Selenium, with a Capybara and RSpec test framework

The coding project folders are stored in the main Windows filing hierarchy and accessed via dev/mnt, but that makes no real difference to development and testing other than making it possible to edit the code using a GUI based editor within Windows.

The problem with browser testing in WSL is that it relies on opening and controlling a web browser, and browsers don’t work on WSL at present as it deliberately doesn’t include X Windows or some other GUI manager - it’s meant to be command line after all. So while you can apt-get firefox, trying to actually run it isn’t going to work.

MadLittleMods

Just some notes and references for myself.

• In bash, you can access your C:\ drive via /mnt/c/
• ~ = C:\Users\MLM\AppData\Local\lxss\home\mlm and is different from your Windows user directory C:\Users\MLM

How to google things

peterfpeterson

Copied from CppCon 2014: Chandler Carruth "Efficiency with Algorithms, Performance with Data Structures" near 37:50

type	time	time	relative
Once cycle on a 3 GHz rocessor	1 ns
L1 cache reference	0.5 ns
Branch mispredict	5 ns
L2 cache reference	7 ns		14x L1 cache
Mutex lock/unlock	25 ns
Main memory refrence	100 ns		20x L2, 200x L1

TrevorJTClarke

/**
 * MediaFormat
 * format and return only needed pieces of media from their public sources
 * Author: Trevor Clarke
 */
function MediaFormat (){
    // http://www.youtube.com/embed/m5yCOSHeYn4
    var ytRegEx = /^(?:https?:\/\/)?(?:i\.|www\.|img\.)?(?:youtu\.be\/|youtube\.com\/|ytimg\.com\/)(?:embed\/|v\/|vi\/|vi_webp\/|watch\?v=|watch\?.+&v=)((\w|-){11})(?:\S+)?$/;
    // http://vimeo.com/3116167, https://player.vimeo.com/video/50489180, http://vimeo.com/channels/3116167, http://vimeo.com/channels/staffpicks/113544877
    var vmRegEx = /https?:\/\/(?:vimeo\.com\/|player\.vimeo\.com\/)(?:video\/|(?:channels\/staffpicks\/|channels\/)|)((\w|-){7,9})/;

kachayev

Channels Are Not Enough

... or Why Pipelining Is Not That Easy

Golang Concurrency Patterns for brave and smart.

By @kachayev

Intro

jirutka

How to use terminal on Windows without going crazy…

Windows is really horrible system for developers and especially for devops. It doesn’t even have a usable terminal and shell, so working with command line is really pain in the ass. If you really don’t want to switch to any usable system (OS X, Linux, BSD…), then this guide should help you to setup somewhat reasonable environment – usable terminal, proper shell, ssh client, git and Sublime Text as a default editor for shell.

Install stuff

1. Download and install Git for Windows* with:
   • [✘] Use Git from the Windows Command Prompt

• [✘] Checkout as-is, commit Unix-style line endings