Mention unattended-upgrades configuration.

[richardkmichael]

The notation to add the Phusion APT repository to an unattended-upgrades configuration is not particularly obvious, so mention it in the installation documentation as an optional step.

Helpful discussion in Ubuntu forums: http://askubuntu.com/questions/64318/how-can-i-enable-silent-automatic-updates-for-google-chrome

[OnixGH]

Merged with fixes in: 4b53d3e

[tsparber]

Hi,

The unattended-upgrades packages provides two ways to specify the allowed origin and archive.

Using in Ubuntu 12.04:

# grep "Origin\|Suite" /var/lib/apt/lists/oss-binaries.phusionpassenger.com*
/var/lib/apt/lists/oss-binaries.phusionpassenger.com_apt_passenger_dists_trusty_Release:Origin: https://packagecloud.io/phusion/passenger
/var/lib/apt/lists/oss-binaries.phusionpassenger.com_apt_passenger_dists_trusty_Release:Suite: trusty

As the passengers origin contains a colon, this causes a problem (s.split(':')), when parsing the /etc/apt/apt.conf.d/50unattended-upgrades file. For example when using sudo unattended-upgrades --dry-run --debug

My suggestion would be to provide the other method as an example (Adding a new block Origins-Pattern to the 50unattended-upgrades):

Unattended-Upgrade::Origins-Pattern {
        "o=https://packagecloud.io/phusion/passenger,a=trusty";
};

This works for on Ubuntu 12.04 using the Version 0.82.1ubuntu2 of the unattended-upgrades.

Related: http://serverfault.com/a/485907