Add IP-based rules (#14963)

db/migrate/20201008202037_create_ip_blocks.rb

@@ -0,0 +1,12 @@
+class CreateIpBlocks < ActiveRecord::Migration[5.2]
+  def change
+    create_table :ip_blocks do |t|
+      t.inet :ip, null: false, default: '0.0.0.0'
+      t.integer :severity, null: false, default: 0
+      t.datetime :expires_at
+      t.text :comment, null: false, default: ''
+
+      t.timestamps
+    end
+  end
+end