Declarative configuration

[JohnAZoidberg]

targetcli has saveconfig to save the current configuration as a JSON file and to later import it, restoring the targets.
This is super useful to configure the targets on reboot.

The JSON config, however, has to be initially created by manually running the targetcli commands.
This has a few drawbacks:

• The commands have to be run on the production system. They don't only generate the config but actually configure targets in the kernel
• The commands fail when the target is already there
• Unlike targetcli clearconfig; targetcli restoreconfig, individual commands don't start from a clean slate
• Activating the configuration for the first time is different than later times (individual commands vs restoreconfig)

What I am looking for, is to describe my desired target configuration and then switch to it - keeping the already configured targets, removing not-anymore configured targets and adding new targets.