Adds a new bool option dnsmasq_enable_addr6_list, when
enabled configuration for dnsmasq will be created with a
single dhcp-host entry specifying a list of ip addresses
allocated for a port.
Previously the dnsmasq dhcp-agent driver would write a
separate dhcp-host entry for each fixed-ip of a port in
the dnsmasq hosts file. The result of the previous
behaviour is that dnsmasq will only use one of the config
entries, i.e the first one matching the mac identifier.
The trade-off is that only a single dns_assignment will
be used for IPv6 addresses within the same subnet. (But
in practice, this was always the case since only the
first config entry would be used by dnsmasq.)
Why is this neccecary:
This is done to enable ironic provisioning over IPv6
using DHCPv6-stateful. For background info, please
read dnsmasq-discuss thread:
http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2020q1/thread.html#13671
Closes-Bug: #1861032
Change-Id: I833840e7daed2efa7efaece27cfd1ba28e0feb90
592c2f8d91