mastodon/config/environments/development.rb

Rails.application.configure do
  # Settings specified here will take precedence over those in config/application.rb.

  # In the development environment your application's code is reloaded on
  # every request. This slows down response time but is perfect for development
  # since you don't have to restart the web server when you make code changes.
  config.cache_classes = false

  # Do not eager load code on boot.
  config.eager_load = false

  # Show full error reports.
  config.consider_all_requests_local = true

  # Enable/disable caching. By default caching is disabled.
  # Run rails dev:cache to toggle caching.
  if Rails.root.join('tmp', 'caching-dev.txt').exist?
    config.action_controller.perform_caching = true
    config.cache_store = :redis_cache_store, REDIS_CACHE_PARAMS
  else
    config.action_controller.perform_caching = false
    config.cache_store = :null_store
  end

  ActiveSupport::Logger.new(STDOUT).tap do |logger|
    logger.formatter = config.log_formatter
    config.logger = ActiveSupport::TaggedLogging.new(logger)
  end

  # Generate random VAPID keys
  Webpush.generate_key.tap do |vapid_key|
    config.x.vapid_private_key = vapid_key.private_key
    config.x.vapid_public_key = vapid_key.public_key
  end

  # Don't care if the mailer can't send.
  config.action_mailer.raise_delivery_errors = false

  config.action_mailer.perform_caching = false

  # Print deprecation notices to the Rails logger.
  config.active_support.deprecation = :log

  # Raise an error on page load if there are pending migrations.
  config.active_record.migration_error = :page_load

  # Debug mode disables concatenation and preprocessing of assets.
  # This option may cause significant delays in view rendering with a large
  # number of complex assets.
  config.assets.debug = true

  # Suppress logger output for asset requests.
  config.assets.quiet = true

  # Adds additional error checking when serving assets at runtime.
  # Checks for improperly declared sprockets dependencies.
  # Raises helpful error messages.
  config.assets.raise_runtime_errors = true

  # Raises error for missing translations
  # config.action_view.raise_on_missing_translations = true

  # Use an evented file watcher to asynchronously detect changes in source code,
  # routes, locales, etc. This feature depends on the listen gem.
  # config.file_watcher = ActiveSupport::EventedFileUpdateChecker

  config.action_mailer.default_options = { from: 'notifications@localhost' }

  # If using a Heroku, Vagrant or generic remote development environment,
  # use letter_opener_web, accessible at  /letter_opener.
  # Otherwise, use letter_opener, which launches a browser window to view sent mail.
  config.action_mailer.delivery_method = (ENV['HEROKU'] || ENV['VAGRANT'] || ENV['REMOTE_DEV']) ? :letter_opener_web : :letter_opener

  # We provide a default secret for the development environment here.
  # This value should not be used in production environments!
  config.x.otp_secret = ENV.fetch('OTP_SECRET', '1fc2b87989afa6351912abeebe31ffc5c476ead9bf8b3d74cbc4a302c7b69a45b40b1bbef3506ddad73e942e15ed5ca4b402bf9a66423626051104f4b5f05109')
end

Redis.raise_deprecations = true