Ruby on Rails: Accessing application credentials

Adding and editing credentials

We open the credentials file like so:

EDITOR="code --wait" rails credentials:edit -e development

Rails will create a new config/master.key file and config/credentials.yml.enc. Keep the master key safe, because anyone with access can decrypt your credentials.

Then we can edit the keys and values:

recaptcha:
  site_key: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

When we are done, we close the file and it gets encrypted.

How to access them in the app:

The right way:

secret_key = Rails.application.credentials.dig(:recaptcha, :secret_key_v3))

We use .dig, because if the credentials are missing/empty it will return nil, instead of crashing:

secret_key = Rails.application.credentials.dig[:recaptcha][:secret_key_v3]

If recaptcha is missing from credentials.yml, then this will return an undefined method '[]' for nil:NilClass (NoMethodError)

Sources

Rails docs, explaining credentials