Subdomains in routes.rb - ruby-on-rails

Question

as I am trying to create web with subodmain for every user i coded as below:
In below controller i am checking if subdomain from sign_in devise page belons to user in User.rb table. If not i am logging out.
class ApplicationController < ActionController::Base
before_action :authenticate_user!
before_action :check_domain
protected
def configure_permitted_parameters
devise_parameter_sanitizer.permit(:sign_up, keys: [:slug])
devise_parameter_sanitizer.permit(:account_update, keys: [:slug])
end
def check_domain
unless current_user.nil?
#domain = User.find_by(email: current_user.email)
if #domain.slug != request.subdomain
sign_out_and_redirect(current_user)
flash.alert = "User not found."
end
end
end
end
At this moment I have routes.rb as below:
Rails.application.routes.draw do
resources :devise
resources :places
resources :people_items
resources :people, only: [:edit, :update]
resources :gift_items
resources :gifts, only: [:edit, :update]
resources :program_items
resources :story_items
devise_for :users
root to: 'pages#index'
get '/home', to: 'output#home'
# For details on the DSL available within this file, see https://guides.rubyonrails.org/routing.html
resources :pages do
member do
delete :delete_file
end
end
resources :stories, only: [:edit, :update]
resources :programs, only: [:edit, :update]
resources :galleries, only: [:edit, :update] do
member do
delete :delete_image
end
end
get 'informations/information'
resources :aboutus, only: [:edit, :update]
end
I modified one more settings in config/environments/development.rb
config.action_dispatch.tld_length = 1
Everything is working fine.
In tutorials i found out that for working subdomains properly I should modify routes.rb as below. But what is the purpose of modification file below? Do I really need to touch routes.rb? That's my question.
constraints subdomain: /.*/ do
resources :pages
end
Do I really need to modify this? Or what is purpose of this modification? Is that really necessary?
Thank you so much for your advices!

Answer 1

Constraints in routes.rb allow you to restrict when routes should or shouldn't be matched, returning a 404 in the event that they do not.
You can do this on a per-route basis for params like so:
get 'products/:category', to: "products#index", category: /(fruit|electronics|medicine)/, as: :products
This would allow requests to http://yourdomain.com/products/fruit but not to http://yourdomain.com/products/vehicles for example. Accessing any forbidden domains would provide you with a 404 response.
You can provide generic constraints to a bunch of different routes by enclosing them in a constraints block, like so:
constraints ->(req) { Site.exists?(subdomain: req.subdomain) } do
resources :articles, path: "blog", only: [:index, :show]
...
end
So here, we're checking that a Site record exists with the subdomain provided. If not, we return a 404.