Add IP-based rules (#14963)

app/models/ip_block.rb

@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+# == Schema Information
+#
+# Table name: ip_blocks
+#
+#  id         :bigint(8)        not null, primary key
+#  created_at :datetime         not null
+#  updated_at :datetime         not null
+#  expires_at :datetime
+#  ip         :inet             default(#<IPAddr: IPv4:0.0.0.0/255.255.255.255>), not null
+#  severity   :integer          default(NULL), not null
+#  comment    :text             default(""), not null
+#
+
+class IpBlock < ApplicationRecord
+  CACHE_KEY = 'blocked_ips'
+
+  include Expireable
+
+  enum severity: {
+    sign_up_requires_approval: 5000,
+    no_access: 9999,
+  }
+
+  validates :ip, :severity, presence: true
+
+  after_commit :reset_cache
+
+  class << self
+    def blocked?(remote_ip)
+      blocked_ips_map = Rails.cache.fetch(CACHE_KEY) { FastIpMap.new(IpBlock.where(severity: :no_access).pluck(:ip)) }
+      blocked_ips_map.include?(remote_ip)
+    end
+  end
+
+  private
+
+  def reset_cache
+    Rails.cache.delete(CACHE_KEY)
+  end
+end