In a clear environment after install lxc and lxc-bridge, when starting the dnsmasq.lxcbr0 you got an error because the dnsmasq's init script calls the firewall function that needs iptables.
* Creating bridge lxcbr0
/lib/rc/sh/openrc-run.sh: line 47: iptables: not found
/lib/rc/sh/openrc-run.sh: line 48: iptables: not found
/lib/rc/sh/openrc-run.sh: line 49: iptables: not found
/lib/rc/sh/openrc-run.sh: line 50: iptables: not found
/lib/rc/sh/openrc-run.sh: line 51: iptables: not found
/lib/rc/sh/openrc-run.sh: line 52: iptables: not found
/lib/rc/sh/openrc-run.sh: line 53: iptables: not found
/lib/rc/sh/openrc-run.sh: line 54: iptables: not found
* Starting dnsmasq.lxcbr0 ...Im just assuming that we want it