knife.rb

# FIRST: Environment variables
knife_env         = ENV['KNIFE_ENV']
knife_org         = ENV['KNIFE_ORG']
knife_config_dir  = ENV['KNIFE_CONFIG_DIR']
knife_config_file = ENV['KNIFE_CONFIG_FILE']

if knife_env.blank?
  `git branch 2> /dev/null` =~ /^\*\s(.*)$/
  git_branch = $1

  if git_branch && git_branch == 'production'
    knife_env = 'production'
  else
    knife_env = 'development'
  end
end

# Defaults
knife_org         ||= 'moriz'
knife_config_dir  ||= '~/.chef'
knife_config_file ||= 'KNIFE_ORG-KNIFE_ENV-knife.rb'
knife_config_file.gsub!(/KNIFE_ENV/, knife_env ).gsub!(/KNIFE_ORG/, knife_org)

# the "real" knife file e.g.:
#       ~/.chef/myorganization-development-knife.rb
#   OR  ~/.chef/myorganization-production-knife.rb
#
knife_file = File.expand_path knife_config_dir + '/' + knife_config_file

unless File.exists? knife_file
  puts "*" * 80
  puts "!!! Could not read #{knife_file} !!!"
  puts
  puts "    => please create this file OR provide settings through the environment."
  puts "*" * 80
  puts "    (see: #{__FILE__} for the loading logic)"
  exit 1
else
  puts knife_file
  # check this url for more details:
  # https://github.com/opscode/mixlib-config/blob/master/lib/mixlib/config.rb#L36
  Chef::Config.from_file knife_file
end