access rails 5.2 encrypted credentials from a script outside the rails app

encrypted_credentials_read.rb

#First of all, require all of rails (maybe it doesn't need to be all, but for now it is)

require 'rails/all'

#then i need to slightly overwrite a rails method:

def encrypted(path, key_path: "config/master.key", env_key: "RAILS_MASTER_KEY")
    ActiveSupport::EncryptedConfiguration.new(
      config_path: path,
      key_path: key_path,
      env_key: env_key,
      raise_if_missing_key: nil
    )
 end

# Then, load the credentials into a YAML object:
credentials = YAML.load(encrypted(File.expand_path("config/credentials.yml.enc"), key_path: File.expand_path("config/master.key")).read)

#Finally, read my credentials:

mail.password = credentials['smtp_password']

very nice, thanks!