Experience container in libvirt

libvirt Is a general virtualization framework , Support xen,kvm,lxc A variety of virtualization technologies , This article is a note .

Set up LXC As the default （ The default is qemu）

export LIBVIRT_DEFAULT_URI=lxc:///

virsh -c lxc:/// Omission

Network settings

NAT

NAT yes libvirt Default by oneself , be called default, Through the following Command view

virsh net-list

Suppose the host has two network cards ,eth0 For the intranet ,eth1 For the Internet , We can bridge out two interfaces for the container ：

#cat lan.xml

<network>

  <name>lan</name>

  <forward mode="bridge" />

      <interface dev="eth0" />

 </network>

#cat wan.xml

<network>

  <name>wan</name>

    <forward mode="bridge" />

      <interface dev="eth1" />

  </network>

Import configuration

virsh net-define lan.xm

virsh net-define wan.xml

Open network card

virsh net-start lan

virsh net-autostart lan

virsh net-start wan

virsh net-autostart wan

Application container

The application container shares various resources of the host , Include kernel , Various software packages , Various libraries , It only has an independent running space , Like a sandbox environment .

Create a file called web Application container for

cat web.xml

<domain type="lxc">

  <name>web</name>

      <memory>102400</memory>

      <os>

        <type>exec</type>

        <init>/bin/sh</init>

    </os>

    <device>

        <console type="pty" />

    </device>

 </domain>

Import virsh

virsh define web.xml

Boot up

virsh autostart web

Into the container

virsh console web

Edit container configuration

virsh edit web

Delete container

virsh undefine web

Operating system container

Operating system container except Linux kernel , It includes a complete set of operating environment , It's like a chroot Environmental Science .

Operating system container creation is a little more complicated

1、 Create the root directory

mkdir -p /lxc/CentOS7

2、 Download and unzip the image   http://images.linuxcontainers.org/images/centos/7/amd64/default/20140807_02:37/rootfs.tar.xz

cd /lxc/centos7

wget  xxx

xz -d rootfs.tar.xz

tar xvf rootfs.tar

3、 establish xml Templates

cat centos7.xml

<domain type="lxc">

 <name>centos7</name>

 <memory unit="KiB">1048576</memory>

 <currentMemory unit="KiB">1048576</currentMemory>

 <resource>

  <partition>/machine</partition>

 </resource>

 <os>

 <clock offset='utc' />

 <on_poweroff>destory</on_poweroff>

 <on_reboot>restart</on_reboot>

 <on_crash>restart<on_crash>

</devices>

 <emulator>/usr/lib/libvirt/libvirt_lxc</emulator>

 <filesystem type='mount' accessmode='passthrough'>

  <source dir='/lxc/centos7'/>

  <target dir='/'/>

  </filesystem>

  <interface type='network'>

  <mac address='00:16:3e:52:87:f1'/>

    <source network='lan'/>

  </interface>

  <console type='pty'>

    <target type='lxc' port='0'/>

    </console>

  </devices>

  </domain>

Import container

virsh define centos7.xml

Start the container

virsh start centos7

virsh autostart centos7

Into the container

virsh console centos7

Stop and start

virsh autostart --disable centos7

sign out lxc console

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