envbash

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Ruby gem for sourcing a bash script to augment the environment.

Rationale

12-factor apps require configuration loaded from the environment.

That's easy on a platform like Heroku, where the environment is preset by the user with commands like heroku config:set. But it's messier in development and non-Heroku deployments, where the environment might need to be loaded from a file.

This package provides a mechanism for sourcing a Bash script to update Ruby's environment (ENV). There are reasons for using a Bash script instead of another configuration language:

  1. Environment variable keys and values should always be strings. Using a Bash script to update the environment enforces that restriction, so there won't be surprises when you deploy into something like Heroku later on.

  2. Using a script means that the values can be sourced into a Bash shell, something that's non-trivial if you use a different config language.

  3. For better or worse, using a script means that environment variables can be set using the full power of the shell, including reading from other files.

Commonly the external file is called env.bash, hence the name of this project.

Installation

Install from RubyGems

gem install envbash

or in your Gemfile:

gem 'envbash'

Usage

Call EnvBash.load to source a Bash script into the current Ruby process. Any variables that are set in the script, regardless of whether they are explicitly exported, will be added to the process environment.

For example, given env.bash with the following content:

FOO='bar baz qux'

This can be loaded into Ruby:

require 'envbash'

EnvBash.load('env.bash')

puts ENV['FOO']  #=> bar baz qux

Copyright 2017 Scampersand LLC

Released under the MIT license