apt unattended-upgrades support

This bug was originally filed in Launchpad as [LP: #1394205](https://bugs.launchpad.net/cloud-init/+bug/1394205)

Launchpad details

affected_projects = []

assignee = None

assignee_name = None

date_closed = None

date_created = 2014-11-19T13:57:22.571212+00:00

date_fix_committed = None

date_fix_released = None

id = 1394205

importance = wishlist

is_complete = False

lp_url = https://bugs.launchpad.net/cloud-init/+bug/1394205

milestone = None

owner = nobuto

owner_name = Nobuto Murata

private = False

status = confirmed

submitter = nobuto

submitter_name = Nobuto Murata

tags = ['cpe-onsite', 'module']

duplicates = []

_Launchpad user **Nobuto Murata(nobuto)** wrote on 2014-11-19T13:57:22.571212+00:00_

At this moment, I usually enable unattended-upgrades in Ubuntu by:
====
#cloud-config
debconf_selections: |
unattended-upgrades unattended-upgrades/enable_auto_updates boolean true
runcmd:
- [ dpkg-reconfigure, -fnoninteractive, unattended-upgrades ]
====

It would be nice if cloud-init supports this operation by one config value for example:
====
#cloud-config
apt_unattended_upgrade: true
====