create ip namespace and connect it to an ovs port

create_fake_vm.sh

#!/bin/bash

[ $EUID -eq 0 ] || { echo 'must be root' >&2; exit 1; }

set -o errexit
# set -x

create_fake_vm() {
    iface_id=$1
    name=$2
    mac=$3
    ip=$4
    mask=$5
    gw=$6
    ipv6_addr=$7
    ipv6_gw=$8
    ip netns add $name
    ovs-vsctl  -- add-port br-int $name  -- set interface $name type=internal  -- set Interface $name external_ids:iface-id=$iface_id
    ip link set $name netns $name
    ip netns exec $name ip link set lo up
    [ -n "$mac" ] && ip netns exec $name ip link set $name address $mac
    if [ "$ip" == "dhcp" ]; then
      ip netns exec $name ip link set $name up
      #ip netns exec $name dhclient -sf /bin/fullstack-dhclient-script --no-pid -1 -v --timeout 10 $name
      ip netns exec $name dhclient -sf /bin/fullstack-dhclient-script --no-pid -nw $name
    else
      ip netns exec $name ip addr add $ip/$mask dev $name
      [ -n "$ipv6_addr" ] && ip netns exec $name ip addr add $ipv6_addr dev $name ||:
      ip netns exec $name ip link set $name up
      ip netns exec $name ip route add default via $gw dev $name
      [ -n "$ipv6_gw" ] && ip netns exec $name ip -6 route add default via $ipv6_gw dev $name ||:
    fi
}

create_fake_vm $@