How do I reload network configuration with cloud-init?

It seems the trick to getting the yaml to generate from the cfg is...

cloud-init clean -r

Next problem is how to get that cfg set from the seed.iso or nocloud-net meta-data

the r flag is the same as any reboot shutdown -r now

If you run cloud-init init (without rebooting) there is not visible change to /etc/netplan/50-cloud-init.yaml

So still not clear on how to trigger that without the reboot? I've tried cloud-init init and then systemctl restart cloud-init

I have also tried cloud-init -d modules --mode config and cloud-init -d modules --mode final

Okay wait I think I found it...

systemctl restart cloud-init-local.service

it seems to rebuild the netplan yaml from the cloud cfg after you cloud-init clean running cloud-init init does not do it. [Ubuntu 19.04 cloud-init 19]

[too many moving parts in this design]

Note: I have found an improvement which brings further clarity both these commands achieve the desired result.

cloud-init clean --logs
cloud-init init --local