This fixes a traceback when attempting to bounce the network after
hostname resets.
In artful and bionic ifupdown package is no longer installed in default
cloud images. As such, Azure can't use those tools to bounce the network
informing DDNS about hostname changes. This doesn't affect DDNS updates
though because systemd-networkd is now watching hostname deltas and with
default behavior to SendHostname=True over dhcp for all hostname updates
which publishes DDNS for us.
ds-identify: failure in NoCloud due to unset variable usage.
The previous OVF datasource change added a debug message that referenced
an un-used variable. The failure path would be triggered if an image was
booted with a iso9660 filesystem attached to a device that was not a
cdrom.
A unit test is added for the specific failure found.
Additional safety to avoid 'cidata' labels is also added to the OVF
checker.
ec2: Use instance-identity doc for region and instance-id
The instance identity document is a better source for region information,
partly because region isn't actually in meta-data at all, only
availability-zone, which happens to be named similarly.
Reviewed-by: Ethan Faust <email address hidden>
Reviewed-by: Cyle Riggs <email address hidden>
Reviewed-by: Tom Kirchner <email address hidden>
Reviewed-by: Matt Nierzwicki <email address hidden>
[<email address hidden>: rebase onto 0.7.9]
[<email address hidden>: changes per merge proposal discussions]
