Data migration task

lib/tasks/devise_two_factor_migration.rake

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+namespace :devise_two_factor do
+  desc 'Copy devise_two_factor OTP secret from old format to new format'
+  task migrate_encryption_format: [:environment] do
+    # Find user records 1_000 at a time
+    User.find_each do |user|
+      # Get the new value on already-updated users, or fall back to legacy value on not yet migrated
+      otp_secret = user.otp_secret
+
+      puts "Processing #{user.email}"
+
+      # This is a no-op for migrated, and will update format for not migrated
+      user.update!(otp_secret: otp_secret)
+    end
+  end
+end