Using dotenv to manage sensitive information

Stripe and Amazon S3 credentials are a couple of common examples of sensitive information that you will frequently store in your app. I've found that the easiest way to store / access this information in your app is through environment variables, and that the best way to manage these values across various apps is with dotenv - specifically with dotenv-rails for Rails apps.

Just add dotenv-rails to your Gemfile

gem 'dotenv-rails', groups: [:development, :test]

Create a file named .env in your project root and set any variable in it like so:

VARIABLE_NAME=some-value-here

And lastly, add this to your .gitignore so that you do not commit your super secret credentials.

.env

If you are using Heroku, setting the environment variables on your server is as simple as heroku config:set VARIABLE_NAME=value, or you can just use the heroku-config gem to push your local environment variables defined in .env with heroku config:push (see more details in the Gem docs).

If you are using a VPS, such as DigitalOcean, you will have to configure the environment variables on the server in a different way. For example, with Unicorn, modify /etc/default/unicorn and add your config there.