roles/juju-setup/templates/daemon.j2

#!/bin/sh

SHELL="/bin/bash"

NIC=$( route|grep default|awk '{print $NF}' )

NAME="${1}"
OP="${2}"
SUBOP="${3}"
ARGS="${4}"

add_port_fwd_rule() {
    DPORT=$1
    VM=$2
    TOPORT=$3

    VMIP=$( getent ahosts $VM|head -1|awk '{print $1}' )
    iptables -t nat -C PREROUTING -p tcp -i $NIC --dport $DPORT -j DNAT --to-destination $VMIP:$TOPORT
    if [ "$?" -ne 0 ]
    then
        iptables -t nat -A PREROUTING -p tcp -i $NIC --dport $DPORT -j DNAT --to-destination $VMIP:$TOPORT
    fi
}

if [ "$OP" = "start" ] || [ "$OP" = "reload" ]
then
    iptables -t nat -F

{% for vm in head_vm_list -%}
{% if vm.forwarded_ports is defined -%}
{% for port in vm.forwarded_ports -%}
    add_port_fwd_rule {{ port.ext }} {{ vm.name }} {{ port.int }}
{% endfor -%}
{% endif -%}
{% endfor -%}

    # Also flush the filter table before rules re-added
    iptables -F
fi