Add whitelist mode (#11291)

app/models/domain_allow.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+# == Schema Information
+#
+# Table name: domain_allows
+#
+#  id         :bigint(8)        not null, primary key
+#  domain     :string           default(""), not null
+#  created_at :datetime         not null
+#  updated_at :datetime         not null
+#
+
+class DomainAllow < ApplicationRecord
+  include DomainNormalizable
+
+  validates :domain, presence: true, uniqueness: true
+
+  scope :matches_domain, ->(value) { where(arel_table[:domain].matches("%#{value}%")) }
+
+  class << self
+    def allowed?(domain)
+      !rule_for(domain).nil?
+    end
+
+    def rule_for(domain)
+      return if domain.blank?
+
+      uri = Addressable::URI.new.tap { |u| u.host = domain.gsub(/[\/]/, '') }
+
+      find_by(domain: uri.normalized_host)
+    end
+  end
+end

app/models/instance.rb

@@ -7,8 +7,9 @@ class Instance
 
   def initialize(resource)
     @domain         = resource.domain
-    @accounts_count = resource.is_a?(DomainBlock) ? nil : resource.accounts_count
+    @accounts_count = resource.respond_to?(:accounts_count) ? resource.accounts_count : nil
     @domain_block   = resource.is_a?(DomainBlock) ? resource : DomainBlock.rule_for(domain)
+    @domain_allow   = resource.is_a?(DomainAllow) ? resource : DomainAllow.rule_for(domain)
   end
 
   def countable?

app/models/instance_filter.rb

@@ -12,6 +12,10 @@ class InstanceFilter
       scope = DomainBlock
       scope = scope.matches_domain(params[:by_domain]) if params[:by_domain].present?
       scope.order(id: :desc)
+    elsif params[:allowed].present?
+      scope = DomainAllow
+      scope = scope.matches_domain(params[:by_domain]) if params[:by_domain].present?
+      scope.order(id: :desc)
     else
       scope = Account.remote
       scope = scope.matches_domain(params[:by_domain]) if params[:by_domain].present?