ENVied

For the rationale behind this project, see this blogpost.

• check for presence and correctness of ENV-variables
• access to typed ENV-variables (integers, booleans etc. instead of just strings)

• Quickstart
• Installation
• Configuration
  • Types
  • Groups
  • Defaults
  • More examples
• Development

After successful installation, define some variables in Envfile:

# file: Envfile
variable :FORCE_SSL, :boolean
variable :PORT, :integer

# during initialization and in a pre-deploy confirmation workflow
ENVied.require

This will throw an error if:

• both ENV['FORCE_SSL'] and ENV['PORT'] are not present.
• the values cannot be coerced to a boolean and integer.

Variables accessed via ENVied are of the correct type:

ENVied.PORT # => 3001
ENVied.FORCE_SSL # => false

Add envied to your Gemfile:

gem 'envied'

If you are using Rails, add this to config/application.rb immediately after Bundler.require(*Rails.groups):

ENVied.require(*ENV['ENVIED_GROUPS'] || Rails.groups)

If you are not using Rails, add the following snippet (or similar) to your app's initialization:

ENVied.require(*ENV['ENVIED_GROUPS'] || [:default, ENV['RACK_ENV']])

Create an Envfile with the following as a starter:

enable_defaults! { ENV['RACK_ENV'] != 'production' }

variable :LOG_LEVEL, :string, default: 'debug'

group :production do
  variable :SECRET_KEY_BASE
end

Refer to the Types section to start configuring your project's environment variables.

To confirm that your ENV variables are set in a pre-deploy workflow, provide the application's current ENV to a Ruby script that loads it and runs the envied check.

ENV.replace(your_current_env)
ENVied.require(*RAILS_GROUPS)
puts "All required ENV variables are present and valid."

If any required ENV are missing, then the check will fail with an error message listing the missing environment variable names.

The following types are supported:

• :string (implied)
• :boolean (e.g. '0'/'1', 'f'/'t', 'false'/'true', 'off'/'on', 'no'/'yes' for resp. false and true)
• :integer
• :float
• :symbol
• :date (e.g. '2014-3-26')
• :time (e.g. '14:00')
• :hash (e.g. 'a=1&b=2' becomes {'a' => '1', 'b' => '2'})
• :array (e.g. 'tag1,tag2' becomes ['tag1', 'tag2'])
• :uri (e.g. 'http://www.google.com' becomes result of URI.parse('http://www.google.com'))

Groups give you more flexibility to define when variables are needed. It's similar to groups in a Gemfile:

# file: Envfile
variable :FORCE_SSL, :boolean, default: 'false'

group :production do
  variable :SECRET_KEY_BASE
end

group :development, :staging do
  variable :DEV_KEY
end

# For local development you would typically do:
ENVied.require(:default) #=> Only ENV['FORCE_SSL'] is required
# On the production server:
ENVied.require(:default, :production) #=> ...also ENV['SECRET_KEY_BASE'] is required

# You can also pass it a string with the groups separated by comma's:
ENVied.require('default, production')

# This allows for easily requiring groups using the ENV:
ENVied.require(ENV['ENVIED_GROUPS'])
# ...then from the prompt:
$ ENVIED_GROUPS='default,production' bin/rails server

# BTW the following are equivalent:
ENVied.require
ENVied.require(:default)
ENVied.require('default')
ENVied.require(nil)

In order to let other developers easily bootstrap the application, you can assign defaults to variables. Defaults can be a value or a Proc (see example below).

Note that 'easily bootstrap' is quite the opposite of 'fail-fast when not all ENV-variables are present'. Therefore you should explicitly state when defaults are allowed:

# Envfile
enable_defaults! { ENV['RACK_ENV'] == 'development' }

variable :FORCE_SSL, :boolean, default: 'false'
variable :PORT, :integer, default: proc {|envied| envied.FORCE_SSL ? 443 : 80 }

Please remember that ENVied only reads from ENV; it doesn't mutate ENV. Don't let setting a default for, say RAILS_ENV, give you the impression that ENV['RAILS_ENV'] is set. As a rule of thumb you should only use defaults:

• for local development
• for ENV-variables that are solely used by your application (i.e. for ENV['STAFF_EMAILS'], not for ENV['RAILS_ENV'])

• See the examples-folder for a more extensive Envfile
• See the Envfile for the bunny_drain application

• bin/setup
• Run tests: RUBYOPT="-W:deprecated" bundle exec rspec
• For an interactive console: bin/console