How to set the configuration for middleware for ActionDispatch::Session::RedisStore and Devise

Question

I'm using the gem redis-rails and doesn't work for api mode. I do not know how to pass the redis configuration for session_store.

Ruby 2.5.0, Rails 5.1.4, Devise 4.4.0, redis-rails 5.0.2

#config/application.rb

config.api_only = true

# needed for devise
config.middleware.use Rack::MethodOverride
config.middleware.use ActionDispatch::Cookies
# needed for redis session in devise
config.middleware.use ActionDispatch::Session::RedisStore, conf_from_initializer_session_store


# config/initializers/session_store.rb
MiApp::Application.config.session_store :redis_store, {
  servers: [
    {
      host: "localhost",
      port: 6379,
      db: 1,
      namespace: "mi_app:session"
    },
  ],
  expire_after: 90.days,
  key: ENV['REDIS_SESSION_KEY']
}

Answer 1

It is possible to pass the redis configuration directly in the middleware.

#config/application.rb
require_relative 'boot'

require "rails"
# Pick the frameworks you want:
require "active_model/railtie"
require "active_job/railtie"
require "active_record/railtie"
require "action_controller/railtie"
require "action_mailer/railtie"
require "action_view/railtie"
require "action_cable/engine"
# require "sprockets/railtie"
# require "rails/test_unit/railtie"

# Require the gems listed in Gemfile, including any gems
# you've limited to :test, :development, or :production.
Bundler.require(*Rails.groups)

module MiApp
  class Application < Rails::Application
    # Initialize configuration defaults for originally generated Rails version.
    config.load_defaults 5.1

    # Settings in config/environments/* take precedence over those specified here.
    # Application configuration should go into files in config/initializers
    # -- all .rb files in that directory are automatically loaded.

    # Only loads a smaller set of middleware suitable for API only apps.
    # Middleware like session, flash, cookies can be added back manually.
    # Skip views, helpers and assets when generating a new resource.
    config.api_only = true

    # needed for devise
    config.middleware.use Rack::MethodOverride
    config.middleware.use ActionDispatch::Cookies
    # needed for redis session in devise
    config.middleware.use ActionDispatch::Session::RedisStore, {
      servers: [
        {
          host: "localhost",
          port: 6379,
          db: 1,
          namespace: "mi_app:session"
        },
      ],
      expire_after: 90.days,
      key: ENV['REDIS_SESSION_KEY']
    }
    # needed for devise views
    # config.middleware.use ActionDispatch::Flash
  end
end