SecretStore
Many secrets of a application, i.e. database credentials, are so far stored in environment variables. In Docker environment reading those secrets from a file is preferred.
SecretStore helps to combine both approaches. A secret with a given name is at first attempted to be read as an environment variable. Only if not found it is read from a file with the fixed name /run/secrets/secret, that contains simple pairs of keys and values and is expected to be delivered by the docker engine as a secret.
Installation
Add this line to your application's Gemfile:
gem 'secret_store'
And then execute:
$ bundle
Or install it yourself as:
$ gem install secret_store
Usage
For instance read the database user :
SecretStore[ :PASSWORD ]