Cloud- init doesn't configure network interfaces in Ubuntu 16.04

[krath]

I'm running vmbuilder 0.12.4 on an Ubuntu 16.04 server to create an Ubuntu 16.04 cloud image.
cloud-init 0.77 is being added to run the cloud image in OpenStack.

Upon starting the VM in OpenStack,
cloud-init fails because the network interface can't be established.
That seems to be related to discrepancy between
/etc/network/interfaces
and
/etc/network/interfaces.d/50-cloud-init.cfg

--> in /etc/network/interfaces, the primary network interface is eth0, whereby in cloud-init it is ens32

auto eth0
iface eth0 inet dhcp

--> changing eth0 to ens32 correctly establishes the network interface

[Scott Moser (smoser)]

Please remove your /etc/network/interfaces definition of 'eth0', and instead have something like below.
Essentially ENI needs to have 'source /etc/network/interfaces/*.cfg' for cloud-init to work correctly. The static 'eth0.cfg' is no longer functional since.

$ cat /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# Source interfaces
# Please check /etc/network/interfaces.d before changing this file
# as interfaces may have been defined in /etc/network/interfaces.d
# See LP: #1262951
source /etc/network/interfaces.d/*.cfg

[krath (thorsten-krause)]

Hey,

that solves the problem, thanks

[kalopaidi (kalopaidi7)]

I am using packer to create templates for cloudstack.
CloudStack 4.2.1
cloud-init 0.77
packer 0.10.0

On a 16.04 instance I followed what is described on post #1 and it works for me also.

When create a new template that deletes the definitions at /etc/network/interfaces, for the instances from that template cloud-init fails because the network interface doesn't come up.

Any ideas?

[James Falcon (falcojr)]

Tracked in Github Issues as https://github.com/canonical/cloud-init/issues/2663