What entropy sources are available on heroku?

Question

I would like to deploy an application to heroku which needs to be able to generate cryptographically secure random numbers. What entropy sources can I use?

Answer 1

Your Heroku dyno is basically an Ubuntu Server VM, so you should have access to /dev/random and /dev/urandom like you would on any other Linux-based OS.

If you're using Ruby/Rails, you should probably be using SecureRandom (or ActiveSupport::SecureRandom for older versions of Ruby and Rails) for this.