Comment 11 for bug 1674946

Also verified it with xenial and a config-drive that had "type": "dvs" in openstack/latest/network_data.json using the proposed package:

root@x1-fixed:~# apt-cache policy cloud-init
cloud-init:
  Installed: 0.7.9-90-g61eb03fe-0ubuntu1~16.04.1
  Candidate: 0.7.9-90-g61eb03fe-0ubuntu1~16.04.1
  Version table:
 *** 0.7.9-90-g61eb03fe-0ubuntu1~16.04.1 500
        500 http://archive.ubuntu.com/ubuntu xenial-proposed/main amd64 Packages

$ lxc file pull x1-fixed/run/cloud-init/result.json
{
 "v1": {
  "datasource": "DataSourceNoCloud [seed=/var/lib/cloud/seed/nocloud-net][dsmode=net]",
  "errors": []
 }
}

To make sure my config-drive was being used, I injected a failure by setting an unknown link type of "dvs-andreas-was-here-again":
$ lxc file pull x1-fixed/run/cloud-init/result.json -
{
 "v1": {
  "datasource": null,
  "errors": [
   "Unknown network_data link type: dvs-andreas-was-here-again",
   "Unknown network_data link type: dvs-andreas-was-here-again"
  ]
 }
}

and

$ lxc exec x1-fixed -- grep dvs-andreas-was-here-again /var/log/cloud-init.log
ValueError: Unknown network_data link type: dvs-andreas-was-here-again