The easiest of enabling unattended updates for your system is to edit the file 50unattended-upgrades inside /etc/atp/apt.conf.d/ with your favourite text editor and comment out the commented sections of the Allowed Origins block, ie
sudo gedit /etc/apt/apt.conf.d/50unattended-upgrades
Change
Unattended-Upgrade::Allowed-Origins {
"${distro_id} ${distro_codename}-security";
// "${distro_id} ${distro_codename}-updates";
// "${distro_id} ${distro_codename}-proposed";
// "${distro_id} ${distro_codename}-backports";
};
to
Unattended-Upgrade::Allowed-Origins {
"${distro_id} ${distro_codename}-security";
"${distro_id} ${distro_codename}-updates";
// "${distro_id} ${distro_codename}-proposed";
// "${distro_id} ${distro_codename}-backports";
};
For software that is not on the Ubuntu repos that you would like to update you need to add a origin and archive to the file. To find what those are for your PPAs open the folder /var/lib/apt/lists/, that is the storage area for state information for each package resource. What you are looking for is the files that end with Release in the name.
Open one with your text editor, ie for Google Chrome:
gedit /var/lib/apt/lists/dl.google.com_linux_chrome_deb_dists_stable_Release
Origin: Google, Inc.
Label: Google
Suite: stable
Codename: stable
Version: 1.0
Date: Thu, 17 Nov 2011 19:09:01 +0000
Architectures: i386 amd64
Components: main
Description: Google chrome-linux repository.
The origin is obvious (Origin: Google, Inc.) and the archive will be whatever is under the line Suite (Suite: stable).
If the Release files does not contain those lines then probably it will not be possible to use that source with unattended upgrades.
After you noted those 2 lines you need to edit the 50unattended-upgrades file and add the lines using this format "<origin>:<archive>"; of for this examples sake "Google\, Inc.:stable";.
Google Chrome's origin is kinda tricky because it has a space a end point and a comma in it but most Release files will be easy to read.
Do not forget to make a backup of your 50unattended-upgrades file before editing it, do that with sudo cp /etc/apt/apt.conf.d/50unattended-upgrades /etc/apt/apt.conf.d/50unattended-upgrades.bak.
To test the changes done on the file you can use sudo unattended-upgrades with the parameters --dry-run and --debug.
--dry-run will run an unattended upgrades cycle except it will not really install the upgrades, only check and verify that everything is ok.
--debug will enable verbose mode.
You can always check the logs for unattended-upgrades at /var/log/unattended-upgrades/unattended-upgrades.log.
You can change the configuration of the unattended upgrades by editing the file /etc/apt/apt.conf.d/10periodic, options for the configuration are in the /etc/cron.daily/apt script header. Read them to configure the frequency of the unattended upgrades.
