# apt install unattended-upgrades
in /etc/apt/apt.conf.d/50unattended-upgrades
“Ubuntu:bionic-updates”;”Ubuntu:bionic-updates”;
Unattended-Upgrade::Remove-Unused-Kernel-Packages “true”;
Unattended-Upgrade::Automatic-Reboot “true”;
Unattended-Upgrade::Automatic-Reboot-Time “03:00”;
in /etc/apt/apt.conf.d/20auto-upgrades
APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Download-Upgradeable-Packages "1";
APT::Periodic::AutocleanInterval "7";
APT::Periodic::Unattended-Upgrade "1";
You can test running:
# unattended-upgrades –dry-run –debug