Row-level Multitenancy with ActsAsTenant (Rails 7)

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From the GoRails video:

https://gorails.com/episodes/row-level-multitenancy-in-rails

Their Rails 4.2.1 example code:

https://github.com/gorails-screencasts/row-level-multitenancy

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I first created the project in Rubymine as Rails app using:

• rails 7.0.4.3
• ruby 3.2.2
• database: postgresql
• javascript: importmaps
• additional option: none

After project setup in Rubymine, add .idea to .gitignore file.

Then ran:

bundle exec rake db:drop db:create db:migrate db:seed

Commit: 'Initial project setup', 173d0ac

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The video assumes an existing rails project with devise already installed. So I did that setup.

I first added the devise and acts_as_tenant gems to the Gemfile and ran:

bundle # same as 'bundle install

Then ran:

bundle exec rails generate devise:install
bundle exec rails generate devise:views

The devise install walks through the steps to add the following to the config/environments/development.rb file:

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

I also added the following to the config/environments/development.rb file to use the 'lvh.me' host name, which is a new requirement in recent versions of Rails:

config.hosts << 'lvh.me' # allows lvh.me to work in development
config.hosts << /.*\.lvh\.me/ # allows subdomains to work in development

I did not change or configure devise in any other way.

I then created a controller to use as the root of the application:

bundle exec rails generate controller Hello index

...and set the root in the routes.rb file:

Rails.application.routes.draw do
  root "hello#index"
end

Part of the devise setup is to create a User model:

bundle exec rails generate devise User

Then ran the db migration:

bundle exec rake db:migrate

I was then able to start the server and see the root page at: http://lvh.me:3000

Commit: 'Gems, devise, User, and root route setup', 78e1ba3

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Next, I added the filter to the application controller for tenant lookup.

Then added an initializer for acts_as_tenant, turning the require_tenant setting off.

This allows the application to run without a tenant, which assumes there is a top level presence in a multi-tenant system that has access to all tenant data.

Next in the video, I scaffolded Post with a belongs_to User so that Posts are a tenant specific object:

bundle exec rails generate scaffold Post user:belongs_to title body:text

Then ran the db migration:

bundle exec rake db:migrate

I also added the following to the Post model:

class Post < ApplicationRecord
  acts_as_tenant(:user)
  
  belongs_to :user
end

The acts_as_tenant(:user) line adds a default scope to the Post model that enforces a lookup by the tenant, which in this case is the User model.

Commit: 'Setting up a Post model with a tenant filter', 2789867

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Following along, I then removed user_id from the post params and post forms.

I also added (this is just me, it was not in the video) a menu to get around the application.

Notice the Devise sign out link uses a different format for Rails 7 now that it includes Turbo.

<div>
  <span><%= link_to 'Home |', root_path %></span>
  <span><%= link_to 'Sign Up |', new_user_registration_path %></span>
  <span><%= link_to 'Login |', user_session_path %></span>
  <span><%= link_to 'Posts |', posts_path %></span>
  <span><%= link_to 'New Post |', new_post_path %></span>
  <span><%= link_to 'Logout', destroy_user_session_path, data: { turbo_method: :delete } %></span>
</div>

This requiring the delete method is set automatically by default in the Devise initializer as:

config.sign_out_via = :delete

Commit: 'Post controller and forms setup', a915038

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At this point I was able to regster two new users ([email protected], [email protected]), login, and create posts which only show up based on the tenant associated with the post. Which, in this case is "User".

This next part wasn't in the video but I added a redirect after login to the posts index page:

def after_sign_in_path_for(resource)
  stored_location_for(resource) || posts_path
end

This takes you right to posts so you can see that they are being filtered.

Commit: 'Login redirect', 0956ac4

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