原本以為使用 DEBIAN_FRONTEND=noninteractive 參數就可以：
sudo DEBIAN_FRONTEND=noninteractive apt upgrade
後來發現還有個套件叫做 needrestart，預設會在 apt upgrade 完成後詢問哪一些服務要重新啟動：
which services should be restarted先檢查一下是否有安裝 needrestart，有的話可以看到 /etc/needrestart 目錄。
再去修改設定檔 needrestart.conf：
# Restart mode: (l)ist only, (i)nteractive or (a)utomatically.
#
# ATTENTION: If needrestart is configured to run in interactive mode but is run
# non-interactive (i.e. unattended-upgrades) it will fallback to list only mode.
#
$nrconf{restart} = 'a';
參考資料：