Services: Kea DHCPv4/v6: Remove depend constraint of ddns_reverse_zone (#10182)
Since ddns_forward_zone already depends on ddns_dns_server, and the config generator bails if either of these are empty we do not need to protect ddns_reverse_zone in any specific way right now.
It's a good idea to keep it this way, only populating a reverse zone is very uncommon, and ISC also tethered it to the forward zone being there.
(cherry picked from commit 4a1d6cf0851940f352f6d414240792c9f66be91a)
Services: Kea DHCPv4/v6: Use KeaCtrl python lib for kea_prefix_watcher to switch to polling the socket instead of streaming the csv lease files. The running configuration has structured output, and we stay in memory without needing to read and parse any files. The tradeoff is that we always have to process the full set of leases, yet by using lease6-get-page which is especially made for efficient bulk operations, this should be rather cheap. The main benefit is we always work with structured json data, can filter for ID_PD better, and reprocess the full truth on every poll interval to ensure the whole setup is self-healing
radvd: make a note for dev/debug and closes #10048
Ideally this should be refactored a bit to flush the configuration
regardless of enabled state, but the legacy code has no separate
template flush so it is tied to service (re)start and we are going
to leave it at a note.
(cherry picked from commit fd780bb1dc9e68ae10520491c5e1f5d0e967a256)
System: Gateways: Configuration: add nosync option
Excluding gateways from synchronization can be useful in cases
where a different default upstream gateway is used to keep
connectivity when failing over in a HA setup.
(cherry picked from commit 8f8a4c8c35de3a1212d5942385a041d0cf1a8273)
