hostonly-ifup

#!/bin/bash
# Author: www.byte-edu.com
# Description: To Create a Host-Only network model for the virtual machine instances.

BridgeName=v-switch0
HostVirtIP=172.16.10.254/24
VirtNic=$1

# 安装 btctl 工具
InstallBrctl(){
  which brctl > /dev/null 2>&1
  if [ $? -eq 0 ];then
    echo "brctl has been installed."
  else
    yum install bridge-utils -y > /dev/null 2>&1
    [ $? -eq 0 ] && echo "brctl was successfully installed" || (echo "brctl installation failed" && exit 1)
  fi
}

# 创建虚拟桥
CreateSwitch(){
  ip link show ${BridgeName} > /dev/null 2>&1
  if [ $? -eq 0 ];then
    echo "The Bridge:[${BridgeName}] is exist."
  else
    brctl addbr ${BridgeName} && echo "The Bridge:[${BridgeName}] was created successfully." || (echo "The Bridge:[${BridgeName}] was created failed." && exit 1)
    ip link set ${BridgeName} up
  fi
}


# 添加虚拟机实例网卡到虚拟桥
AttachVirNic(){
  if [ "${VirtNic}" ];then
    ip link set ${VirtNic} up
    sleep 0.5s
    brctl addif ${BridgeName} ${VirtNic}
    [ $? -eq 0 ]&& echo "Attach Tap nic to ${BridgeName} succeeded." || (echo "Attach Tap nic to ${BridgeName} failed." && exit 1)
  else
    echo "The tap nic is not exist"
    exit 1
  fi
}

# 添加宿主机虚拟网卡地址到虚拟桥
AttachVirHostNic(){
  BridgeIP=$(ip addr show ${BridgeName} | grep -w 'inet' |awk {'print $2'})
  if [ "${BridgeIP}" == "${HostVirtIP}" ];then
    echo "The Bridge:[$BridgeName] has IP. It's Host-Only network"
  elif [ !${BridgeIP} ];then
    ifconfig ${BridgeName} ${HostVirtIP} up && echo "To Create Host-Only network succeeded." || (echo "To Create Host-Only network failed." && exit 1)
  else
    echo "The bridge already has an IP:[${BridgeIP}], but it does not match the address you specified [${HostVirtIP}]."
    exit 1
  fi
}

# 配置主函数
MAIN(){
  InstallBrctl
  CreateSwitch
  AttachVirNic
  AttachVirHostNic
} 

MAIN