czarneckid

Zero downtime deploys with gunicorn

Below are the actual files we use in one of our latest applications at Agora Games to achieve zero downtime deploys with gunicorn. I hope these files and notes help. I am happy to update these files or these notes if there are comments/questions. YMMV (of course).

Salient points for each file:

• gunicorn.py: The pre_fork function looks for gunicorn's old PID file in the proper file and sends the proper QUIT signal to the old process once the new process is running.
• sv-gunicorn-run.jinja: This is the runit template we use in our Salt-managed infrastructure for handling the application process management. You could just as easily convert this to a non-templatized version.

czarneckid

class Fish
  def 🔪
    puts "🍣"
  end
end

🐟 = Fish.new
🐟.🔪

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require 'redis'

redis = Redis.new
redis.script(:flush)
redis.flushdb

hello_name_lua_script = <<-HELLO_NAME_LUA_SCRIPT
local function hello_name(name)
  return("Hello " .. name)
end

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{
	"auto_complete": false,
	"color_scheme": "Packages/Theme - itg.flat/itg.Monokai.tmTheme",
	"detect_slow_plugins": false,
	"file_exclude_patterns":
	[
		"*.pyc",
		"*.pyo",
		"*.exe",
		"*.dll",

czarneckid

{
  "auto_complete": false,
  "color_scheme": "Packages/Base16 Color Schemes/base16-bright.dark.tmTheme",
  "detect_slow_plugins": false,
  "file_exclude_patterns":
  [
    "*.pyc",
    "*.pyo",
    "*.exe",
    "*.dll",

czarneckid

class SampleController < UIViewController
  def viewDidLoad
    super

    self.view.backgroundColor = UIColor.whiteColor

    @text_view = UITextView.alloc.initWithFrame(UIScreen.mainScreen.applicationFrame)
    @text_view.text = sample_text
    @text_view.editable = false
    @text_view.showsHorizontalScrollIndicator = true

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# Setup the application's runit directory
/etc/sv/application:
  file.directory:
    - mode: 0755
    - user: someuser
    - group: someuser
    - recurse:
      - user
      - group
      - mode

czarneckid

class Demo
  def initialize(something)
    @something = something
  end

  def based_on_something
    @something * 2
  end
end

czarneckid

Rails 4 Upgrade Notes

I recently completed our upgrade to Rails 4. Below are various notes and links that may help you if you are upgrading your application to Rails 4. YMMV.

Overview

There is a good Rails Guide on upgrading, with a specific section on upgrading from Rails 3.2 to Rails 4.0. First, a bit about our specific application and the technologies used, pre-Rails 4 upgrade:

• Rails 3.2.14
• Ruby 2.0.0-p247

czarneckid

Zero downtime deploys with unicorn + nginx + runit + rvm + chef

Below are the actual files we use in one of our latest production applications at Agora Games to achieve zero downtime deploys with unicorn. You've probably already read the GitHub blog post on Unicorn and would like to try zero downtime deploys for your application. I hope these files and notes help. I am happy to update these files or these notes if there are comments/questions. YMMV (of course).

Other application notes:

• Our application uses MongoDB, so we don't have database migrations to worry about as with MySQL or postgresql. That does not mean that we won't have to worry about issues with the database with indexes being built in MongoDB or what have you.
• We use capistrano for deployment.

Salient points for each file: