ENVV

ENVV provides a ENV like accessor with schema validation and coerced values.

By providing an explicit schema of required environments variables, it will facilitate collaborative development and deployment.
It will inform you during the boot process of your application if you miss to provide some valid environment variables, avoiding bugs during execution.
Schema and coercition are handled by dry-rb libraries, with the benefits of the powerful DSL of Dry::Schema, its built-in predicates and types.

Installation

Install the gem and add to the application's Gemfile by executing:

$ bundle add envv

If bundler is not being used to manage dependencies, install the gem by executing:

$ gem install envv

Requirements: this library officially supports the following Ruby versions

MRI >= 3.0.0

Usage

Build your ENVV with Dry::Schema.Params rules to describe your env vars requirements.

ENVV.build! do
  required(:MY_STRING_VAR).filled(:string)
  required(:MY_INT_VAR).filled(:integer, gt?: 3000)
  required(:MY_BOOLEAN_VAR).filled(:bool)
end

If requirements are not satisfied, it will raise an exception. So be sure this validation occurs as soon as possible in the boot process of your application. In a Ruby On Rails application, you can place it in an initializer and ensure it will be executed first by naming it app/initializers/01-envv.rb for example, since initializers are run in alphabetical order.

If environment variables are validated, you can now access their coerced value with ENVV#fetch method:

# With ENV
#
# MY_STRING_VAR=hello
# MY_INT_VAR=4000
# MY_BOOLEAN_VAR=True

ENVV.fetch("MY_STRING_VAR") # ⇒ "Hello"
ENVV.fetch("MY_INT_VAR") # ⇒ 4000
ENVV.fetch("MY_BOOLEAN_VAR") # ⇒ true

Adding extra features with your own ENVV wrapper

You can include ENVV::Base in your own class or module and thus provide extra features.

With a module

module MyAppEnv
  extend ENVV::Base

  def is_dark?
    fetch("IS_DARK")
  end
end

MyAppEnv.build! do
  required(:IS_DARK).filled(:bool)
end

# IS_DARK=True

MyAppEnv.is_dark? # => true

With a class

class MyAppEnv
  include ENVV::Base

  def [](key)
    fetch(key)
  end
end

e = MyAppEnv.new.build! do
  required(:IS_DARK).filled(:bool)
end
e["IS_DARK"] # => true

Be creative !

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing