Module: Conker

Defined in:
lib/conker.rb

Overview

Example that uses the process’s environment:

module Conker
  setup_config!(Rails.env, :A_SECRET => api_credential)
end

Example that uses a supplied hash of values (e.g. read from some file or database):

config_values = {:A_SECRET => 'very_secret'}
module Conker
  setup_config!(Rails.env, config_values, :A_SECRET => api_credential)
end

For convenience, if your config file is YAML, you can supply the path directly and Conker will load and parse the file:

module Conker
  setup_config!(Rails.env, 'config_values.yml', :A_SECRET => api_credential)
end

Defined Under Namespace

Classes: Error, MissingDefault, MustBeDefined, UnknownType, VariableDeclaration

Constant Summary collapse

ENVIRONMENTS = 
%w(production development test)
DUMMY_API_KEY = 
'dummy_api_key'.freeze
DUMMY_CRYPTO_SECRET = 
'dummysecretdummysecretdummysecretdummysecretdummysecretdummysecretdummysecre'

Class Method Summary collapse

Class Method Details

.api_credential(declaration_opts = {}) ⇒ Object

Declare an environment variable to be used as a credential for accessing an external API (e.g. username, password, API key, access token): shorthand for required_in_production(:type => :string, :default => ‘dummy_api_key’)



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# File 'lib/conker.rb', line 89

def api_credential(declaration_opts={})
  required_in_production({
    :type => :string,
    :default => DUMMY_API_KEY,
  }.merge(declaration_opts))
end

.crypto_secret(declaration_opts = {}) ⇒ Object

Declare an environment variable to be used as a secret key by some encryption algorithm used in our code.

To generate a secret suitable for production use, try:

openssl rand -hex 256

(which will generate 256 bytes = 2048 bits of randomness).

The distinction between this and api_credential is mainly for documentation purposes, but they also have different defaults.



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# File 'lib/conker.rb', line 105

def crypto_secret(declaration_opts={})
  required_in_production({
    :type => :string,
    :default => DUMMY_CRYPTO_SECRET,
  }.merge(declaration_opts))
end

.optional(declaration_opts = {}) ⇒ Object

Declare an environment variable, defaulting to other values if not defined.

You must either specify a :default, or specify defaults for each of :production, :test and :development.



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# File 'lib/conker.rb', line 124

def optional(declaration_opts = {})
  VariableDeclaration.new(declaration_opts)
end

.redis_url(opts = {}) ⇒ Object

A redis url is required_in_production with development and test defaulting to localhost.



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# File 'lib/conker.rb', line 113

def redis_url(opts={})
  required_in_production({
    :development => "redis://localhost/1",
    :test => "redis://localhost/3"
  }.merge(opts))
end

.required_in_production(declaration_opts = {}) ⇒ Object

Declare an environment variable that is required to be defined in the production environment, and defaults to other values in the test or development environments.

You must either specify a :default, or specify defaults for each of :test and :development.



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# File 'lib/conker.rb', line 81

def required_in_production(declaration_opts={})
  VariableDeclaration.new(declaration_opts.reverse_merge(:required_in => :production))
end

.setup_config!(current_env, *args) ⇒ Object

Parse a multi-key hash into globals and raise an informative error message on failure.



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# File 'lib/conker.rb', line 43

def setup_config!(current_env, *args)
  declarations = args.extract_options!
  values = values_hash(args[0])

  setup_constants(current_env, declarations, values)
end

.setup_rack_environment!(*args) ⇒ Object

Like setup_config! but uses ENV || ‘development’ as the environment. Also sets constant RACK_ENV.

N.B. if using this method, you don’t need to specify :RACK_ENV in your variable declarations, and it will complain if you do. This is partly to make clear that this method *won’t* read RACK_ENV from your config file, only from the environment variable, for compatibility with other code (e.g. Sinatra) that depends directly on the environment variable.



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# File 'lib/conker.rb', line 58

def setup_rack_environment!(*args)
  ENV['RACK_ENV'] ||= 'development'
  set_constant(:RACK_ENV, ENV['RACK_ENV'])

  declarations = args.extract_options!
  values = values_hash(args[0])

  if declarations.key?('RACK_ENV') || declarations.key?(:RACK_ENV)
    raise Error, "No need to declare RACK_ENV; please remove it to avoid confusion!"
  end
  if ENV.key?('RACK_ENV') && values.key?('RACK_ENV') && (env = ENV['RACK_ENV']) != (conf = values['RACK_ENV'])
    raise "RACK_ENV differs between environment (#{env}) and config (#{conf})!  Please remove it from your config."
  end

  setup_constants(ENV['RACK_ENV'], declarations, values)
end