【Rails7】Deviseでユーザー(user)と管理者(admin)を分けてログインできるようにする

gem 'devise'

$ bundle install

$ rails g devise:install

===============================================================================

Depending on your application's configuration some manual setup may be required:

  1. Ensure you have defined default url options in your environments files. Here
     is an example of default_url_options appropriate for a development environment
     in config/environments/development.rb:

       config.action_mailer.default_url_options = { host: 'localhost', port: 3000 }

     In production, :host should be set to the actual host of your application.

     * Required for all applications. *

  2. Ensure you have defined root_url to *something* in your config/routes.rb.
     For example:

       root to: "home#index"
     
     * Not required for API-only Applications *

  3. Ensure you have flash messages in app/views/layouts/application.html.erb.
     For example:

       <p class="notice"><%= notice %></p>
       <p class="alert"><%= alert %></p>

     * Not required for API-only Applications *

  4. You can copy Devise views (for customization) to your app by running:

       rails g devise:views
       
     * Not required *

===============================================================================

config.scoped_views = true

$ rails g devise admin
$ rails g devise user

# frozen_string_literal: true

class DeviseCreateUsers < ActiveRecord::Migration[7.0]
  def change
    create_table :users do |t|
      ## Database authenticatable
      t.string :name  # ←nameカラムを追加する場合は追記する
      t.string :email,              null: false, default: ""
      t.string :encrypted_password, null: false, default: ""

      ## Recoverable
      t.string   :reset_password_token
      t.datetime :reset_password_sent_at

      ## Rememberable
      t.datetime :remember_created_at

      ## Trackable
      # t.integer  :sign_in_count, default: 0, null: false
      # t.datetime :current_sign_in_at
      # t.datetime :last_sign_in_at
      # t.string   :current_sign_in_ip
      # t.string   :last_sign_in_ip

      # Confirmable  # ↓メール認証を有効にする場合はコメントアウトを外す
      t.string   :confirmation_token
      t.datetime :confirmed_at
      t.datetime :confirmation_sent_at
      t.string   :unconfirmed_email # Only if using reconfirmable

      ## Lockable
      # t.integer  :failed_attempts, default: 0, null: false # Only if lock strategy is :failed_attempts
      # t.string   :unlock_token # Only if unlock strategy is :email or :both
      # t.datetime :locked_at


      t.timestamps null: false
    end

    add_index :users, :email,                unique: true
    add_index :users, :reset_password_token, unique: true
    # add_index :users, :confirmation_token,   unique: true
    # add_index :users, :unlock_token,         unique: true
  end
end

$ rails db:migrate

$ rails g devise:controllers admins
$ rails g devise:controllers users

$ rails g devise:views admins
$ rails g devise:views users

Rails.application.routes.draw do
  ・・・
  devise_for :users
  devise_for :admins
end

Rails.application.routes.draw do
  ・・・
  devise_for :admins, controllers: {
    # ↓ローカルに追加されたコントローラーを参照する(コントローラー名: "コントローラーの参照先")
    registrations: "admins/registrations",
    sessions: "admins/sessions",
    passwords: "admins/passwords",
    confirmations: "admins/confirmations"
  }
  devise_for :users, controllers: {
    # ↓ローカルに追加されたコントローラーを参照する(コントローラー名: "コントローラーの参照先")
    registrations: "users/registrations",
    sessions: "users/sessions",
    passwords: "users/passwords",
    confirmations: "users/confirmations"
  }
end