How to configure automatic updates on your raspberry pi and make sure it reboots in the night (if required)

apt-get install unattended-upgrades apt-listchanges

sed -i 's/^\/\/      "o=Raspbian,n=jessie"/      "o=Raspbian,n=jessie"/g' /etc/apt/apt.conf.d/50unattended-upgrades
sed -i 's/^\/\/Unattended-Upgrade::Mail "root";/Unattended-Upgrade::Mail "root";/g' /etc/apt/apt.conf.d/50unattended-upgrades
sed -i 's/^\/\/Unattended-Upgrade::Automatic-Reboot "false";/Unattended-Upgrade::Automatic-Reboot "true";/g' /etc/apt/apt.conf.d/50unattended-upgrades
sed -i 's/^\/\/Unattended-Upgrade::Automatic-Reboot-Time "02:00";/Unattended-Upgrade::Automatic-Reboot-Time "02:00";/g' /etc/apt/apt.conf.d/50unattended-upgrades

tee /etc/apt/apt.conf.d/20auto-upgrades > /dev/null <<EOF
APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Unattended-Upgrade "1";
EOF

Check the next day the log /var/log/unattended-upgrades/unattended-upgrades.log to see if it worked 🙂

Source: here