Azure: bouncing of network device/publishing of hostname fails on artful

Launch an instance on Azure (20171005.1) and I find in /var/log/cloud-init.log
the following:

2017-10-10 21:16:25,598 - DataSourceAzure.py[WARNING]: Failed publishing hostname: Unexpected error while running command.
Command: ['sh', '-xc', 'i=$interface; x=0; ifdown $i || x=$?; ifup $i || x=$?; exit $x']
Exit code: 127
Reason: -
Stdout: -
Stderr: -
2017-10-10 21:16:25,598 - util.py[WARNING]: handling set_hostname failed
2017-10-10 21:16:25,598 - util.py[DEBUG]: handling set_hostname failed
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/cloudinit/sources/DataSourceAzure.py", line 286, in bounce_network_with_azure_hostname
    prev_hostname=previous_hostname)
  File "/usr/lib/python3/dist-packages/cloudinit/sources/DataSourceAzure.py", line 637, in perform_hostname_bounce
    'env': env})
  File "/usr/lib/python3/dist-packages/cloudinit/util.py", line 2238, in log_time
    ret = func(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/cloudinit/util.py", line 1847, in subp
    cmd=args)
cloudinit.util.ProcessExecutionError: Unexpected error while running command.
Command: ['sh', '-xc', 'i=$interface; x=0; ifdown $i || x=$?; ifup $i || x=$?; exit $x']
Exit code: 127
Reason: -
Stdout: -
Stderr: -

The command output is not captured, so we see in /var/log/cloud-init-output.log:

+ i=eth0
+ x=0
+ ifdown eth0
sh: 1: ifdown: not found
+ x=127
+ ifup eth0
sh: 1: ifup: not found
+ x=127
+ exit 127

This is not surprising, there is no 'ifup' or 'ifdown', so the attempt to
"bounce" the network device in order to re-publish the hostname that
has been set will fail.

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: cloud-init 17.1-17-g45d361cb-0ubuntu1
ProcVersionSignature: Ubuntu 4.13.0-12.13-generic 4.13.3
Uname: Linux 4.13.0-12-generic x86_64
ApportVersion: 2.20.7-0ubuntu2
Architecture: amd64
CloudName: Azure
Date: Tue Oct 10 21:45:09 2017
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=C.UTF-8
 SHELL=/bin/bash
SourcePackage: cloud-init
UpgradeStatus: No upgrade log present (probably fresh install)
user_data.txt:

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