Tag Archives: Ruby

Moving config mess from environment files to config.yml

If your environments/*.rb look like a repetitive mess, its time to get a config.yml!

  • overview of your configuration
  • dry code
  • (optional) not check in all the passwords/keys of your app (only check in config.example.yml), great for open-source apps
  • Can be loaded without loading the environment (e.g. small rake tasks)
# lib/cfg.rb
CFG = YAML.load(ERB.new(
  File.read("config/config.yml")
).result)[Rails.env].with_indifferent_access

# config/application.rb
require "cfg"

# config/config.yml
common: &common
  api:
    airbrake_key: xxx
    google_analytics_key: yyy
  admin_email: admin@example.com

test:
  <<: *common
  host: 'localhost'

development:
  <<: *common
  host: 'localhost'

production:
  <<: *common
  host: 'fuu.bar'

# config/application.rb
config.action_mailer.default_url_options = {:host => CFG[:host]}

vpn-fuse aka kill this app when vpn fails

Lets say you are running something over VPN,
and VPN suddenly fails, then this will kill the app you dont want to connect via the normal interface.

Its just a small ruby script you can put into e.g. /usr/bin/

vpn-fuse VpnName 'killall secret-app'
vpn-fuse BankNetwork 'killall bank-client'
vpn-fuse iPredator 'killall transmission-gtk'
...

so far only tested on Ubuntu…

vpn-fuse

Do not show I18n missing translation tooltips in production

Problem:
Lots of stuff does not need any translation, so we simply leave it untranslated (e.g. firstname shows as Firstname). But this leaves ugly “missing translation” spans in out html.
Instead of entering senseless translations for everything thats missing, we simply deactivate the tooltips in production, while also avoiding raising/rescuing theses MissingTranslation errors to improve performance(rescue/raise is not cheap).

Code:

# https://grosser.it/2012/02/04/do-not-show-i18n-missing-translation-tooltips-in-production/
# config/initializers/disable_i18n_tooltips.rb
# missing translations
# - Do not show tooltips in production/test
# - Do not raise ( speedup) for every missing translations
I18n::Backend::Base.class_eval do
  def translate_with_default(locale, key, options = {})
    if options[:rescue_format] == :html && ['test','production'].include?(Rails.env)
      default = key.to_s.gsub('_', ' ').gsub(/\b('?[a-z])/) { $1.capitalize }
      options.reverse_merge!(default: default)
    end
    translate_without_default(locale, key, options)
  end

  alias_method_chain :translate, :default
end

parallel_split_test — Split slow tests into multiple chunks and run them in parallel

If you want to run 1 big/slow test file, use Parallel-Split-Test, it splits it into multiple chunks and then runs them in parallel.

PS: If you have lots of tests you should take a look at Parallel-Tests, which runs multiple files in parallel.

This became necessary because in our current project: spec runtime=3h (without integration) / slowest file=5 minutes. Now this time is only 1/3rd.

Prevent ActionMailer from sending to deleted users / blacklisted addresses

No need to check in normal code, just do everything as usual and this interceptor will prevent you from spamming people who do not want any emails.
Its not perfect(missing bc/bcc filters but if should be fine for 90% of cases)

#config/initializers/blacklisted_emails.rb
class MailInterceptor
  def self.delivering_email(message)
    if User.where(:email => message.to, :receive_emails => false).any?
      message.perform_deliveries = false
    end
  end
end

Mail.register_interceptor(MailInterceptor)