[pve-devel] [RFC SDN DHCP] Add and Remove DHCP mappings on vNIC add/remove

[Stefan Lendl <s.lendl@proxmox.com>]

Date: Fri, 27 Oct 2023 13:00:49 +0200
From 96fee0866727a1188b1debd805c625c598816b98 Mon Sep 17 00:00:00 2001
This patch series defines IPs, once allocated by the IPAM as persistant
until the vNIC is removed from the VM or the VM is destroyed.

The dnsmasq ethers file is a pure product of the IPAM database and does
not have it's own state, therefore removing the potential issue of wrong
sync state between IPAM and dnsmasq.
Updating the ethers file is only done on the effected node.

Technically, starting the VM still adds the DHCP mapping. This is needed
at the moment because during migration, this triggers generating the
ethers file on the target node.  If the IPAM already contains the
mapping, it returns the existing IP (upsert)

Alternative approach would be to trigger an update of the ethers file on
all nodes on IPAM update.

Stopping a guest does not effect IPAM/DHCP.

Destroying a guest removes the associated IPs from the IPAM.

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