最重要的几行是：
"origin=Raspbian,codename=${distro_codename},label=Raspbian";
"origin=Raspberry Pi Foundation,codename=${distro_codename},label=Raspberry Pi Foundation";
这是整个文件（/etc/apt/apt.conf.d/50unattended-upgrades）：
// Unattended-Upgrade::Origins-Pattern controls which packages are
// upgraded.
//
// Lines below have the format format is "keyword=value,...". A
// package will be upgraded only if the values in its metadata match
// all the supplied keywords in a line. (In other words, omitted
// keywords are wild cards.) The keywords originate from the Release
// file, but several aliases are accepted. The accepted keywords are:
// a,archive,suite (eg, "stable")
// c,component (eg, "main", "contrib", "non-free")
// l,label (eg, "Rapsbian", "Raspbian")
// o,origin (eg, "Raspbian", "Unofficial Multimedia Packages")
// n,codename (eg, "jessie", "jessie-updates")
// site (eg, "http.debian.net")
// The available values on the system are printed by the command
// "apt-cache policy", and can be debugged by running
// "unattended-upgrades -d" and looking at the log file.
//
// Within lines unattended-upgrades allows 2 macros whose values are
// derived from /etc/debian_version:
// ${distro_id} Installed origin.
// ${distro_codename} Installed codename (eg, "jessie")
Unattended-Upgrade::Origins-Pattern {
// Codename based matching:
// This will follow the migration of a release through different
// archives (e.g. from testing to stable and later oldstable).
// "o=Raspbian,n=jessie";
// "o=Raspbian,n=jessie-updates";
// "o=Raspbian,n=jessie-proposed-updates";
// "o=Raspbian,n=jessie,l=Raspbian";
// Archive or Suite based matching:
// Note that this will silently match a different release after
// migration to the specified archive (e.g. testing becomes the
// new stable).
// "o=Raspbian,a=stable";
// "o=Raspbian,a=testing";
"origin=Raspbian,codename=${distro_codename},label=Raspbian";
// Additionally, for those running Raspbian on a Raspberry Pi,
// match packages from the Raspberry Pi Foundation as well.
"origin=Raspberry Pi Foundation,codename=${distro_codename},label=Raspberry Pi Foundation";
};
// List of packages to not update (regexp are supported)
Unattended-Upgrade::Package-Blacklist {
// "vim";
// "libc6";
// "libc6-dev";
// "libc6-i686";
};
// This option allows you to control if on a unclean dpkg exit
// unattended-upgrades will automatically run
// dpkg --force-confold --configure -a
// The default is true, to ensure updates keep getting installed
//Unattended-Upgrade::AutoFixInterruptedDpkg "false";
// Split the upgrade into the smallest possible chunks so that
// they can be interrupted with SIGTERM. This makes the upgrade
// a bit slower but it has the benefit that shutdown while a upgrade
// is running is possible (with a small delay)
//Unattended-Upgrade::MinimalSteps "false";
// Install all unattended-upgrades when the machine is shutting down
// instead of doing it in the background while the machine is running
// This will (obviously) make shutdown slower
//Unattended-Upgrade::InstallOnShutdown "true";
// Send email to this address for problems or packages upgrades
// If empty or unset then no email is sent, make sure that you
// have a working mail setup on your system. A package that provides
// 'mailx' must be installed. E.g. "user@example.com"
//Unattended-Upgrade::Mail "root";
// Set this value to "true" to get emails only on errors. Default
// is to always send a mail if Unattended-Upgrade::Mail is set
//Unattended-Upgrade::MailOnlyOnError "true";
// Do automatic removal of new unused dependencies after the upgrade
// (equivalent to apt-get autoremove)
//Unattended-Upgrade::Remove-Unused-Dependencies "false";
// Automatically reboot *WITHOUT CONFIRMATION* if
// the file /var/run/reboot-required is found after the upgrade
//Unattended-Upgrade::Automatic-Reboot "false";
// If automatic reboot is enabled and needed, reboot at the specific
// time instead of immediately
// Default: "now"
//Unattended-Upgrade::Automatic-Reboot-Time "02:00";
// Use apt bandwidth limit feature, this example limits the download
// speed to 70kb/sec
//Acquire::http::Dl-Limit "70";
上游源代码：https : //github.com/mvo5/unattended-upgrades/blob/master/data/50unattended-upgrades.Raspbian
sudo unattended-upgrade -d来自wiki.debian.org/UnattendedUpgrades