Code review comment for ~bitfehler/cloud-init:bitfehler/load_seed

Looking at the first bug:

https://bugs.launchpad.net/cloud-init/+bug/1809180

I understand it to:
  1) boot NoCloud (fallback networking is utilized)
  2) at cloud-init init stage, NoCloud-Net is loaded, which now supports reading URLs
     including network-config files from URL.
  3) during init stage the .network_config property on NoCloudNet is provided via loading the seed and reading the URLs
  4) cloud-init init stage will render an updated network-config to the system.

This leaves a system with a fallback network config up (including dhclient) but the on-disk network-config is from the URL. On subsequent boots, it will utilize the network-config from the seed URL.

This appears to resolve the request; though it's not completely clear without more feedback from the submitter w.r.t the use-case "boot an image in a new environment without running cloud-init a second time".

A more complete fix would be to modify NoCloud to use EphemeralDHCP to bring up networking if a seed prefix included URLs (as Scott suggests in (b)).

The second bug suggests exactly (b).

I don't think it would be too much more effort to pull in the EphemeralDHCP bits.