03 Feb 2014
Don't let your shell manage your env vars: Use Dotenv or Figaro instead
Problem
During the development of https://webhookbook.com, I changed the SMTP credentials. Because I’m a good developer I was storing my credentials in environment variables, so I ssh’d into my production server, updated .bashrc with the new values, and restarted the server. Done, right?
Not done. It turned out that because I was defining my env vars in my .bashrc and performing ‘hot’ restarts of my Unicorn server (using the kill -s USR2 unicorn_pid method) the environment was never getting reloaded, so the old credentials were still in use. Oops!
Solutions
Fortunately, there are a number of gems out there to help you with this problem.
Dotenv (https://github.com/bkeepers/dotenv) and Figaro (https://github.com/laserlemon/figaro) are very similar gems that both provide the ability to add environment variables in a config file. They parse said file during app initialization and load the stored variables into the ENV hash.
The main concrete difference I can see (aside from using differently named yml files) is that Figaro allows you to access ENV vars via the Figaro.env object as well as the ENV hash. The argument here is that it’s easier to stub out Figaro.env than a raw hash during testing.
Personally I’m using Dotenv at the moment, but you can basically flip a coin to pick the one you want to use.
There are other solutions available that provide settings management in Rails, but I prefer Dotenv and Figaro because they hook into the existing environment rather than requiring me to access a different object to get my settings. They allow you to access configuration uniformly throughout the app, even if you’re also relying on externally defined environment variables.
As a bonus, updating my env vars is now easier. I can just scp a new version of the file over to the production box before restarting the server. No need to manually edit pesky remote files. Yay!
Thanks for reading! If you like my writing, you may be interested in my book: Healthy Webhook Consumption with Rails
David at 15:34
