docbrown/docs/backend/configuration.md

title
Configuration

Configuration

We currently use the following gems for configuring the application:

• dotenv
• rails-settings-cached
• vault

dotenv

This gem is used for configuring environment variables for test and development environments. Examples:

• REDIS_URL
• FASTLY_API_KEY
• STRIPE_SECRET_KEY

Settings managed via your ENV can be found in Configuring Environment Variables) and viewed at /admin/config (see the Admin guide):

rails-settings-cached

We use this gem for managing settings used within the app's business logic. Examples:

• main_social_image
• rate_limit_follow_count_daily
• suggested_tags

These settings can be accessed via the SiteConfig object and viewed / modified via /admin/config (see the Admin guide).

Vault

The vault Ruby gem allows us to interact with Vault. In a nutshell, Vault is a tool for securely storing and accessing secrets. It is completely optional for running a Forem. To access it we use the wrapper AppSecrets.

class AppSecrets
  def self.[](key)
    result = Vault.kv(namespace).read(key)&.data&.fetch(:value) if ENV["VAULT_TOKEN"].present?
    result ||= ApplicationConfig[key]

    result
  rescue Vault::VaultError
    ApplicationConfig[key]
  end

  def self.[]=(key, value)
    Vault.kv(namespace).write(key, value: value)
  end

  def self.namespace
    ENV["VAULT_SECRET_NAMESPACE"]
  end
  private_class_method :namespace
end

We attempt to access a secret from Vault if it is enabled, i.e. if the VAULT_TOKEN is present. If Vault is not enabled or if we cannot find the secret in it, then we fallback to fetching the secret from the ApplicationConfig.

One advantage of using Vault with Forem is that it allows you to update your secrets easily through the application rather than having to mess with ENV files. If you would like to try out Vault, follow our installation guide for setting it up locally.