Acts As Tenant
Row-level multitenancy for Ruby on Rails apps.
This gem was born out of our own need for a fail-safe and out-of-the-way manner to add multi-tenancy to our Rails app through a shared database strategy, that integrates (near) seamless with Rails.
acts_as_tenant adds the ability to scope models to a tenant. Tenants are represented by a tenant model, such as
Account. acts_as_tenant will help you set the current tenant on each request and ensures all 'tenant models' are always properly scoped to the current tenant: when viewing, searching and creating.
In addition, acts_as_tenant:
- sets the current tenant using the subdomain or allows you to pass in the current tenant yourself
- protects against various types of nastiness directed at circumventing the tenant scoping
- adds a method to validate uniqueness to a tenant,
- sets up a helper method containing the current tenant
Note: acts_as_tenant was introduced in this blog post.
Row-level vs schema multitenancy
What's the difference?
Row-level multitenancy each model must have a tenant ID column on it. This makes it easy to filter records for each tenant using your standard database columns and indexes. ActsAsTenant uses row-level multitenancy.
Schema multitenancy uses database schemas to handle multitenancy. For this approach, your database has multiple schemas and each schema contains your database tables. Schemas require migrations to be run against each tenant and generally makes it harder to scale as you add more tenants. The Apartment gem uses schema multitenancy.
Want to see how it works? Check out the ActsAsTenant walkthrough video:
acts_as_tenant will only work on Rails 5.2 and up. This is due to changes made to the handling of
default_scope, an essential pillar of the gem.
To use it, add it to your Gemfile:
There are two steps in adding multi-tenancy to your app with acts_as_tenant:
- setting the current tenant and
- scoping your models.
Setting the current tenant
There are three ways to set the current tenant:
- by using the subdomain to lookup the current tenant,
- by setting the current tenant in the controller, and
- by setting the current tenant for a block.
Looking Up Tenants
By Subdomain to lookup the current tenant
class ApplicationController < ActionController::Base set_current_tenant_by_subdomain(:account, :subdomain) end
This tells acts_as_tenant to use the last subdomain to identify the current tenant. In addition, it tells acts_as_tenant that tenants are represented by the Account model and this model has a column named 'subdomain' which can be used to lookup the Account using the actual subdomain. If ommitted, the parameters will default to the values used above.
By default, the last subdomain will be used for lookup. Pass in
subdomain_lookup: :first to use the first subdomain instead.
By Domain to lookup the current tenant
class ApplicationController < ActionController::Base set_current_tenant_by_subdomain_or_domain(:account, :subdomain, :domain) end
You can locate the tenant using
set_current_tenant_by_subdomain_or_domain( :account, :subdomain, :domain ) which will check for a subdomain and fallback to domain.
By default, the last subdomain will be used for lookup. Pass in
subdomain_lookup: :first to use the first subdomain instead.
Manually using before_action
class ApplicationController < ActionController::Base set_current_tenant_through_filter before_action :your_method_that_finds_the_current_tenant def your_method_that_finds_the_current_tenant current_account = Account.find_it set_current_tenant(current_account) end end
current_tenant yourself, requires you to declare
set_current_tenant_through_filter at the top of your application_controller to tell acts_as_tenant that you are going to use a before_action to setup the current tenant. Next you should actually setup that before_action to fetch the current tenant and pass it to
acts_as_tenant by using
set_current_tenant(current_tenant) in the before_action.
If you are setting the tenant in a specific controller (except
application_controller), it should to be included AT THE TOP of the file.
class MembersController < ActionController::Base set_current_tenant_through_filter before_action :set_tenant before_action :set_member, only: [:show, :edit, :update, :destroy] def set_tenant set_current_tenant(current_user.account) end end
This allows the tenant to be set before any other code runs so everything is within the current tenant.
Setting the current tenant for a block
ActsAsTenant.with_tenant(current_account) do # Current tenant is set for all code in this block end
This approach is useful when running background processes for a specified tenant. For example, by putting this in your worker's run method, any code in this block will be scoped to the current tenant. All methods that set the current tenant are thread safe.
Note: If the current tenant is not set by one of these methods, Acts_as_tenant will be unable to apply the proper scope to your models. So make sure you use one of the two methods to tell acts_as_tenant about the current tenant.
Disabling tenant checking for a block
ActsAsTenant.without_tenant do # Tenant checking is disabled for all code in this block end
This is useful in shared routes such as admin panels or internal dashboards when
require_tenant option is enabled throughout the app.
Allowing tenant updating for a block
ActsAsTenant.with_mutable_tenant do # Tenant updating is enabled for all code in this block end
This will allow you to change the tenant of a model. This feature is useful for admin screens, where it is ok to allow certain users to change the tenant on existing models in specific cases.
Require tenant to be set always
If you want to require the tenant to be set at all times, you can configure acts_as_tenant to raise an error when a query is made without a tenant available. See below under configuration options.
Scoping your models
class AddAccountToUsers < ActiveRecord::Migration def up add_column :users, :account_id, :integer add_index :users, :account_id end end class User < ActiveRecord::Base acts_as_tenant(:account) end
acts_as_tenant requires each scoped model to have a column in its schema linking it to a tenant. Adding
acts_as_tenant to your model declaration will scope that model to the current tenant BUT ONLY if a current tenant has been set.
Some examples to illustrate this behavior:
# This manually sets the current tenant for testing purposes. In your app this is handled by the gem. ActsAsTenant.current_tenant = Account.find(3) # All searches are scoped by the tenant, the following searches will only return objects # where account_id == 3 Project.all => # all projects with account_id => 3 Project.tasks.all # => all tasks with account_id => 3 # New objects are scoped to the current tenant @project = Project.new(:name => 'big project') # => <#Project id: nil, name: 'big project', :account_id: 3> # It will not allow the creation of objects outside the current_tenant scope @project.account_id = 2 @project.save # => false # It will not allow association with objects outside the current tenant scope # Assuming the Project with ID: 2 does not belong to Account with ID: 3 @task = Task.new # => <#Task id: nil, name: nil, project_id: nil, :account_id: 3>
Acts_as_tenant uses Rails'
default_scope method to scope models. Rails 3.1 changed the way
default_scope works in a good way. A user defined
default_scope should integrate seamlessly with the one added by
Validating attribute uniqueness
If you need to validate for uniqueness, chances are that you want to scope this validation to a tenant. You can do so by using:
validates_uniqueness_to_tenant :name, :email
All options available to Rails' own
validates_uniqueness_of are also available to this method.
You can explicitly specifiy a foreign_key for AaT to use should the key differ from the default:
acts_as_tenant(:account, :foreign_key => 'accountID') # by default AaT expects account_id
You can also explicitly specifiy a primary_key for AaT to use should the key differ from the default:
acts_as_tenant(:account, :primary_key => 'primaryID') # by default AaT expects id
Has and belongs to many
You can scope a model that is part of a HABTM relationship by using the
class Organisation < ActiveRecord::Base has_many :organisations_users has_many :users, through: :organisations_users end class User < ActiveRecord::Base has_many :organisations_users acts_as_tenant :organisation, through: :organisations_users end class OrganisationsUser < ActiveRecord::Base belongs_to :user acts_as_tenant :organisation end
An initializer can be created to control (currently one) option in ActsAsTenant. Defaults
are shown below with sample overrides following. In
ActsAsTenant.configure do |config| config.require_tenant = false # true end
config.require_tenantwhen set to true will raise an ActsAsTenant::NoTenant error whenever a query is made without a tenant set.
config.require_tenant can also be assigned a lambda that is evaluated at run time. For example:
ActsAsTenant.configure do |config| config.require_tenant = lambda do if $request_env.present? return false if $request_env["REQUEST_PATH"].start_with?("/admin/") end end end
ActsAsTenant.should_require_tenant? is used to determine if a tenant is required in the current context, either by evaluating the lambda provided, or by returning the boolean value assigned to
acts_as_tenant :account includes the belongs_to relationship.
So when using acts_as_tenant on a model, do not add
belongs_to :account alongside
class User < ActiveRecord::Base acts_as_tenant(:account) # YES belongs_to :account # REDUNDANT end
You can add the following
belongs_to options to
:foreign_key, :class_name, :inverse_of, :optional, :primary_key, :counter_cache, :polymorphic, :touch
acts_as_tenant(:account, counter_cache: true)
ActsAsTenant supports Sidekiq. A background processing library.
Add the following code to your
If you set the
current_tenant in your tests, make sure to clean up the tenant after each test by calling
ActsAsTenant.current_tenant = nil. Integration tests are more difficult: manually setting the
current_tenant value will not survive across multiple requests, even if they take place within the same test. This can result in undesired boilerplate to set the desired tenant. Moreover, the efficacy of the test can be compromised because the set
current_tenant value will carry over into the request-response cycle.
To address this issue, ActsAsTenant provides for a
test_tenant value that can be set to allow for setup and post-request expectation testing. It should be used in conjunction with middleware that clears out this value while an integration test is processing. A typical Rails and RSpec setup might look like:
# test.rb require_dependency 'acts_as_tenant/test_tenant_middleware' Rails.application.configure do config.middleware.use ActsAsTenant::TestTenantMiddleware end
# spec_helper.rb config.before(:suite) do |example| # Make the default tenant globally available to the tests $default_account = Account.create! end config.before(:each) do |example| if example.metadata[:type] == :request # Set the `test_tenant` value for integration tests ActsAsTenant.test_tenant = $default_account else # Otherwise just use current_tenant ActsAsTenant.current_tenant = $default_account end end config.after(:each) do |example| # Clear any tenancy that might have been set ActsAsTenant.current_tenant = nil ActsAsTenant.test_tenant = nil end
Bug reports & suggested improvements
If you have found a bug or want to suggest an improvement, please use our issue tracked at:
If you want to contribute, fork the project, code your improvements and make a pull request on Github. When doing so, please don't forget to add tests. If your contribution is fixing a bug it would be perfect if you could also submit a failing test, illustrating the issue.
Contributing to this gem
We use the Appraisal gem to run tests against supported versions of Rails to test for compatibility against them all. StandardRb also helps keep code formatted cleanly.
- Fork the repo
- Make changes
- Run test suite with
bundle exec appraisal
bundle exec standardrbto standardize code formatting
- Submit a PR
Author & Credits
acts_as_tenant is written by Erwin Matthijssen & Chris Oliver.
This gem was inspired by Ryan Sonnek's Multitenant gem and its use of default_scope.
Copyright (c) 2011 Erwin Matthijssen, released under the MIT license