Comment 40 for bug 1636912

Hi. This issue affected us on Xenial; we explicitly enable systemd-networkd on our images (when creating our AMI), and after a recent AMI rebuild we were no longer able to start our AMIs. When I looked at the system console we saw things that looked like:

[ 52.866176] cloud-init[721]: Cloud-init v. 0.7.8 running 'init' at Wed, 30 Nov 2016 03:13:22 +0000. Up 51.74 seconds.
[ 52.873058] cloud-init[721]: ci-info: +++++++++++++++++++++++++++Net device info++++++++++++++++++++++++++++
[ 52.879734] cloud-init[721]: ci-info: +--------+-------+-----------+-----------+-------+-------------------+
[ 52.886030] cloud-init[721]: ci-info: | Device | Up | Address | Mask | Scope | Hw-Address |
[ 52.892162] cloud-init[721]: ci-info: +--------+-------+-----------+-----------+-------+-------------------+
[ 52.897909] cloud-init[721]: ci-info: | lo | True | 127.0.0.1 | 255.0.0.0 | . | . |
[ 52.904408] cloud-init[721]: ci-info: | lo | True | ::1/128 | . | host | . |
[ 52.910315] cloud-init[721]: ci-info: | ens3 | False | . | . | . | 0a:c6:90:b1:76:26 |
[ 52.916070] cloud-init[721]: ci-info: +--------+-------+-----------+-----------+-------+-------------------+
[ 52.921096] cloud-init[721]: 2016-11-30 03:13:23,567 - url_helper.py[WARNING]: Calling 'http://169.254.169.254/2009-04-04/meta-data/instance-id' failed [0/120s]: request error [HTTPConnectionPool(host='169.254.169.254', port=80): Max retries exceeded with url: /2009-04-04/meta-data/instance-id (Caused by NewConnectionError('<requests.packages.urllib3.connection.HTTPConnection object at 0x7f4feee32cf8>: Failed to establish a new connection: [Errno 101] Network is unreachable',))]

I eventually noticed that (in comparison to the system log for an older working AMI) the "Starting Network Service" line was missing and found this bug. (Text above included mostly in case anybody else sees the same issue and searches for the error.)

I tested with xenial-proposed and 229-4ubuntu13, and it fixed the issue. I'd love to see this fix in stable xenial soon!