12factor and dotenv - how to keep you API keys secret

12factor and dotenv for node

also

dotenv is also available for golang, php, python and ruby

# aptitude search dotenv

p golang-github-joho-godotenv-dev - Go port of Ruby's dotenv library 
p php-symfony-dotenv - .env files parser to make environment variables accessible 
p python3-dotenv - Get and set values in the .env file in local and production servers
p ruby-dotenv - configuration variable loader