cloud-init init fails on 18.04 in the networking part

[Roman Plessl]

I use the following cloud-init configuration works perfectly for Ubuntu 14.04, Ubuntu 16.04, Debian 8, Debian 9 and Centos 7 but not with the new Ubuntu 18.04

--- 8< 8< 8< ---
#cloud-config

datasource:
  Ec2:
    strict_id: false

hostname: my_cloudserver_name
phone_home:
  url: http://169.254.169.254/2009-04-04/done
  post: [ instance_id ]
  tries: 10

users:
  - default

ssh_authorized_keys:
  - "ssh-rsa AAA ....=="
--- 8< 8< 8< ---

The installation process hangs here and will fail:

2018-02-01 13:37:47,126 - DataSourceEc2.py[WARNING]: Did not find a fallback interface on EC2.
2018-02-01 13:37:47,126 - util.py[WARNING]: failed stage init
failed run of stage init
------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/cloudinit/cmd/main.py", line 650, in status_wrapper
    ret = functor(name, args)
  File "/usr/lib/python3/dist-packages/cloudinit/cmd/main.py", line 357, in main_init
    init.apply_network_config(bring_up=bool(mode != sources.DSMODE_LOCAL))
  File "/usr/lib/python3/dist-packages/cloudinit/stages.py", line 635, in apply_network_config
    netcfg, src = self._find_networking_config()
  File "/usr/lib/python3/dist-packages/cloudinit/stages.py", line 622, in _find_networking_config
    if self.datasource and hasattr(self.datasource, 'network_config'):
  File "/usr/lib/python3/dist-packages/cloudinit/sources/DataSourceEc2.py", line 338, in network_config
    macs_to_nics = {net.get_interface_mac(iface): iface}
  File "/usr/lib/python3/dist-packages/cloudinit/net/__init__.py", line 506, in get_interface_mac
    if os.path.isdir(sys_dev_path(ifname, "bonding_slave")):
  File "/usr/lib/python3/dist-packages/cloudinit/net/__init__.py", line 38, in sys_dev_path
    return get_sys_class_path() + devname + "/" + path
TypeError: must be str, not NoneType
------------------------------------------------------------

after adding:

--- 8< 8< 8< ---
packages:
  - ifupdown
--- 8< 8< 8< ---

the cloud-init works as wished.

---
...
ci-info: +-------+---------------+---------------+-----------------+-----------+-------+
2018-02-01 14:19:41,576 - DataSourceEc2.py[WARNING]: Metadata 'network' key not valid: None.
2018-02-01 14:19:41,777 - cc_resizefs.py[WARNING]: Device '/dev/vda1' did not exist. cannot resize: dev=/dev/vda1 mnt_point=/ path=/
Generating public/private rsa key pair.
...
---

It seems there is a dependency in cloud-init to the pre-netplan networking system in 18.04.

[Roman Plessl (roman-plessl)]

root@cloud-nine-141:/var/lib/cloud# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu Bionic Beaver (development branch)
Release: 18.04
Codename: bionic

[Roman Plessl (roman-plessl)]

root@cloud-nine-141:/var/lib/cloud# apt-cache policy cloud-init
cloud-init:
  Installed: 17.2-13-g6299e8d0-0ubuntu1
  Candidate: 17.2-13-g6299e8d0-0ubuntu1
  Version table:
 *** 17.2-13-g6299e8d0-0ubuntu1 500
        500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages
        100 /var/lib/dpkg/status

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[James Falcon (falcojr)]

If this is still reproduceable on supported versions of Ubuntu, please re-open a new issue and attach logs.