Add script to setup external bridge

This script can be used to setup an external bridge
and add physical NIC to it so that one can expose
OSv IP on LAN.

This script would normally be executed before
scripts/run.py or scripts/firecracker.py which would
then receive name of the bridge (ie virbr1) as a -b
parameter.

Signed-off-by: Waldemar Kozaczuk <[email protected]>

scripts/setup-external-bridge.sh

@@ -0,0 +1,27 @@
+#!/bin/bash
+
+# This script setup a bridge that binds physical NIC
+# to it and allows exposing OSv guest IP on external network
+
+if [[ $(whoami) != "root" ]]; then
+  echo "This script needs to be run as root!"
+  exit -1
+fi
+
+NIC_NAME=$1
+if [[ "$NIC_NAME" == "" ]]; then
+  echo "Usage: ./scripts/setup-external-bridge.sh <NIC_NAME> <BRIDGE_NAME> (optional)"
+  exit -1
+fi
+
+BRIDGE_NAME=$2
+if [[ "$BRIDGE_NAME" == "" ]]; then
+  BRIDGE_NAME="virbr1"
+fi
+
+ip addr flush dev $NIC_NAME          # Clear IP address on physical ethernet device
+brctl addbr $BRIDGE_NAME             # Create bridge
+brctl addif $BRIDGE_NAME $NIC_NAME   # Add physical ethernet device to bridge
+sysctl -q -w net.ipv6.conf.$BRIDGE_NAME.disable_ipv6=1
+dhclient -v $BRIDGE_NAME             # Grab IP addres from DHCP server
+echo "Setup bridge: $BRIDGE_NAME"