kvm虚拟化
1. 虚拟化介绍
虚拟化是云计算的基础。简单的说，虚拟化使得在一台物理的服务器上可以跑多台虚拟机，虚拟机共享物理机的 CPU、内存、IO 硬件资源，但逻辑上虚拟机之间是相互隔离的。
物理机我们一般称为宿主机（Host），宿主机上面的虚拟机称为客户机（Guest）。
那么 Host 是如何将自己的硬件资源虚拟化，并提供给 Guest 使用的呢？
这个主要是通过一个叫做 Hypervisor 的程序实现的。
根据 Hypervisor 的实现方式和所处的位置，虚拟化又分为两种：
- 全虚拟化
- 半虚拟化
全虚拟化：
Hypervisor 直接安装在物理机上，多个虚拟机在 Hypervisor 上运行。Hypervisor 实现方式一般是一个特殊定制的 Linux 系统。Xen 和 VMWare 的 ESXi 都属于这个类型
半虚拟化：
物理机上首先安装常规的操作系统，比如 Redhat、Ubuntu 和 Windows。Hypervisor 作为 OS 上的一个程序模块运行，并对管理虚拟机进行管理。KVM、VirtualBox 和 VMWare Workstation 都属于这个类型
理论上讲：
全虚拟化一般对硬件虚拟化功能进行了特别优化，性能上比半虚拟化要高；
半虚拟化因为基于普通的操作系统，会比较灵活，比如支持虚拟机嵌套。嵌套意味着可以在KVM虚拟机中再运行KVM。
2. kvm介绍
kVM 全称是 Kernel-Based Virtual Machine。也就是说 KVM 是基于 Linux 内核实现的。
KVM有一个内核模块叫 kvm.ko，只用于管理虚拟 CPU 和内存。
那 IO 的虚拟化，比如存储和网络设备则是由 Linux 内核与Qemu来实现。
作为一个 Hypervisor，KVM 本身只关注虚拟机调度和内存管理这两个方面。IO 外设的任务交给 Linux 内核和 Qemu。
大家在网上看 KVM 相关文章的时候肯定经常会看到 Libvirt 这个东西。
Libvirt 就是 KVM 的管理工具。
其实，Libvirt 除了能管理 KVM 这种 Hypervisor，还能管理 Xen，VirtualBox 等。
Libvirt 包含 3 个东西：后台 daemon 程序 libvirtd、API 库和命令行工具 virsh
- libvirtd是服务程序，接收和处理 API 请求；
- API 库使得其他人可以开发基于 Libvirt 的高级工具，比如 virt-manager，这是个图形化的 KVM 管理工具；
- virsh 是我们经常要用的 KVM 命令行工具
3. kvm部署
环境说明：
| 系统类型 | IP |
|---|---|
| RHEL7 | 192.168.47.128 |
3.1 kvm安装
部署前请确保你的CPU虚拟化功能已开启。分为两种情况：
- 虚拟机要关机设置CPU虚拟化
- 物理机要在BIOS里开启CPU虚拟化
//关闭防火墙与SELINUX
[root@peng~]# systemctl stop firewalld
[root@peng ~]# systemctl disable firewalld
Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
[root@peng ~]# setenforce 0
[root@peng ~]# sed -ri 's/^(SELINUX=).*/\1disabled/g' /etc/selinux/config
[root@peng ~]# reboot
//配置网络源
[root@peng ~]# curl -o /etc/yum.repos.d/CentOS7-Base-163.repo http://mirrors.163.com/.help/CentOS7-Base-163.repo
[root@peng ~]# sed -i 's/\$releasever/7/g' /etc/yum.repos.d/CentOS7-Base-163.repo
[root@peng ~]# sed -i 's/^enabled=.*/enabled=1/g' /etc/yum.repos.d/CentOS7-Base-163.repo
[root@peng ~]# yum -y install epel-release vim wget net-tools unzip zip gcc gcc-c++
安装过程略.....
//验证CPU是否支持KVM；如果结果中有vmx（Intel）或svm(AMD)字样，就说明CPU的支持的
[root@peng ~]# egrep -o 'vmx|svm' /proc/cpuinfo
vmx
vmx
//kvm安装
[root@peng ~]# yum -y install qemu-kvm qemu-kvm-tools qemu-img virt-manager libvirt libvirt-python libvirt-client virt-install virt-viewer bridge-utils libguestfs-tools
安装过程略......
//因为虚拟机中网络，我们一般都是和公司的其他服务器是同一个网段，所以我们需要把KVM服务器的网卡配置成桥接模式。这样的话KVM的虚拟机就可以通过该桥接网卡和公司内部其他服务器处于同一网段
//此处我的网卡是ens32，所以用br0来桥接ens32网卡
[root@peng ~]# cd /etc/sysconfig/network-scripts/
[root@peng network-scripts]# cp ifcfg-ens33 ifcfg-br0
[root@peng network-scripts]# vim br0
[root@peng network-scripts]# vim ifcfg-br0
[root@peng network-scripts]# cat ifcfg-br0
TYPE=Bridge
DEVICE=br0
NM_CONTROLLED=no
BOOTPROTO=static
NAME=br0
ONBOOT=yes
IPADDR=192.168.47.128
NETMASK=255.255.255.0
GATEWAY=192.168.47.2
DNS1=114.114.114.114
DNS2=8.8.8.8
[root@peng network-scripts]# vim ifcfg-ens32
[root@peng network-scripts]# cat ifcfg-ens32
TYPE=Ethernet
BOOTPROTO=static
NAME=ens32
DEVICE=ens32
ONBOOT=yes
BRIDGE=br0
NM_CONTROLLED=no
//重启网络
[root@peng network-scripts]# systemctl restart network
[root@peng network-scripts]# ip a
1: lo: mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens32: mtu 1500 qdisc pfifo_fast master br0 state UP group default qlen 1000
link/ether 00:0c:29:34:c4:ed brd ff:ff:ff:ff:ff:ff
inet6 fe80::20c:29ff:fe34:c4ed/64 scope link
valid_lft forever preferred_lft forever
3: br0: mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 00:0c:29:34:c4:ed brd ff:ff:ff:ff:ff:ff
inet 192.168.47.128/24 brd 192.168.47.255 scope global br0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe34:c4ed/64 scope link
valid_lft forever preferred_lft forever
//启动服务
[root@peng network-scripts]# systemctl start libvirtd
[root@peng network-scripts]# systemctl enable libvirtd
//验证安装结果
[root@peng network-scripts]# lsmod|grep kvm
kvm_intel 174841 0
kvm 578518 1 kvm_intel
irqbypass 13503 1 kvm
//测试并验证安装结果
[root@peng network-scripts]# virsh -c qemu:///system list
Id 名称 状态
----------------------------------------------------
[root@peng ~]# virsh --version
4.5.0
[root@peng ~]# virt-install --version
1.5.0
[root@peng ~]# ln -s /usr/libexec/qemu-kvm /usr/bin/qemu-kvm
[root@peng ~]# ll /usr/bin/qemu-kvm
lrwxrwxrwx 1 root root 21 3月 11 18:29 /usr/bin/qemu-kvm -> /usr/libexec/qemu-kvm
//查看网桥信息
[root@peng ~]# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.000c2934c4ed no ens32
virbr0 8000.525400a09fba yes virbr0-nic
3.2 kvm web管理界面安装
kvm 的 web 管理界面是由 webvirtmgr 程序提供的。
//安装依赖包
[root@peng ~]# yum -y install git python-pip libvirt-python libxml2-python python-websockify supervisor nginx python-devel
//升级pip
[root@peng ~]# pip install --upgrade pip
Retrying (Retry(total=4, connect=None, read=None, redirect=None)) after connection broken by 'ReadTimeoutError("HTTPSConnectionPool(host='pypi.python.org', port=443): Read timed out. (read timeout=15)",)': /simple/pip/
Collecting pip
Downloading https://files.pythonhosted.org/packages/d8/f3/413bab4ff08e1fc4828dfc59996d721917df8e8583ea85385d51125dceff/pip-19.0.3-py2.py3-none-any.whl (1.4MB)
100% |████████████████████████████████| 1.4MB 714kB/s
Installing collected packages: pip
Found existing installation: pip 8.1.2
Uninstalling pip-8.1.2:
Successfully uninstalled pip-8.1.2
Successfully installed pip-19.0.3
//从github上下载webvirtmgr代码
[root@peng ~]# cd /usr/local/src/
[root@peng src]# git clone git://github.com/retspen/webvirtmgr.git
正克隆到 'webvirtmgr'...
remote: Enumerating objects: 5614, done.
remote: Total 5614 (delta 0), reused 0 (delta 0), pack-reused 5614
接收对象中: 100% (5614/5614), 2.98 MiB | 1.23 MiB/s, done.
处理 delta 中: 100% (3602/3602), done.
//安装webvirtmgr
[root@peng src]# ls
webvirtmgr
[root@peng src]# cd webvirtmgr/
[root@peng webvirtmgr]# pip install -r requirements.txt
DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 won't be maintained after that date. A future version of pip will drop support for Python 2.7.
Collecting django==1.5.5 (from -r requirements.txt (line 1))
Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ReadTimeoutError("HTTPSConnectionPool(host='pypi.org', port=443): Read timed out. (read timeout=15)",)': /simple/django/
Downloading https://files.pythonhosted.org/packages/38/49/93511c5d3367b6b21fc2995a0e53399721afc15e4cd6eb57be879ae13ad4/Django-1.5.5.tar.gz (8.1MB)
100% |████████████████████████████████| 8.1MB 429kB/s
Collecting gunicorn==19.5.0 (from -r requirements.txt (line 2))
Downloading https://files.pythonhosted.org/packages/f9/4e/f4076a1a57fc1e75edc0828db365cfa9005f9f6b4a51b489ae39a91eb4be/gunicorn-19.5.0-py2.py3-none-any.whl (113kB)
100% |████████████████████████████████| 122kB 4.5MB/s
Collecting lockfile>=0.9 (from -r requirements.txt (line 5))
Downloading https://files.pythonhosted.org/packages/c8/22/9460e311f340cb62d26a38c419b1381b8593b0bb6b5d1f056938b086d362/lockfile-0.12.2-py2.py3-none-any.whl
Installing collected packages: django, gunicorn, lockfile
Running setup.py install for django ... done
Successfully installed django-1.5.5 gunicorn-19.5.0 lockfile-0.12.2
//检查sqlite3是否安装
[root@peng webvirtmgr]# python
Python 2.7.5 (default, Oct 30 2018, 23:45:53)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-36)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import sqlite3
>>> exit()
//初始化帐号信息
[root@peng webvirtmgr]# python manage.py syncdb
WARNING:root:No local_settings file found.
Creating tables ...
Creating table auth_permission
Creating table auth_group_permissions
Creating table auth_group
Creating table auth_user_groups
Creating table auth_user_user_permissions
Creating table auth_user
Creating table django_content_type
Creating table django_session
Creating table django_site
Creating table servers_compute
Creating table instance_instance
Creating table create_flavor
You just installed Django's auth system, which means you don't have any superusers defined.
Would you like to create one now? (yes/no): yes //问你是否创建超级管理员帐号
Username (leave blank to use 'root'): //指定超级管理员帐号用户名，默认留空为root
Email address: [email protected] //设置超级管理员邮箱
Password: //设置超级管理员密码
Password (again): //再次输入超级管理员密码
Superuser created successfully.
Installing custom SQL ...
Installing indexes ...
Installed 6 object(s) from 1 fixture(s)
//拷贝web网页至指定目录
[root@peng webvirtmgr]# mkdir /var/www
[root@peng webvirtmgr]# cp -r /usr/local/src/webvirtmgr /var/www/
[root@peng webvirtmgr]# chown -R nginx.nginx /var/www/webvirtmgr/
//生成密钥
[root@peng ~]# ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
Created directory '/root/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:vy0JhHU1/EePX3OG4vzXCQqhzWAScxHSDSc3bkU62zk root@peng
The key's randomart image is:
+---[RSA 2048]----+
| ..==+.=o |
| o.o*.= .. .|
| +o * . +.|
| ..oo.+ o +.*|
| o.S..E . ++|
| ..= +. .|
| .o.... o|
| o+ ..o|
| ... . |
+----[SHA256]-----+
//由于这里webvirtmgr和kvm服务部署在同一台机器，所以这里本地信任。如果kvm部署在其他机器，那么这个是它的ip
[root@peng ~]# ssh-copy-id 192.168.47.128
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.47.128 (192.168.47.128)' can't be established.
ECDSA key fingerprint is SHA256:L65bqtH6w45rHO/HvXOlb/4MoS4Z6+pZNOrIPfuhTjQ.
ECDSA key fingerprint is MD5:9d:86:9c:fc:50:ee:d2:34:39:b3:ff:b0:d9:42:fc:b6.
Are you sure you want to continue connecting (yes/no)? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
[email protected]'s password:
Number of key(s) added: 1
Now try logging into the machine, with: "ssh '192.168.47.128'"
and check to make sure that only the key(s) you wanted were added.
//配置端口转发
[root@peng ~]# ssh 192.168.47.128 -L localhost:8000:localhost:8000 -L localhost:6080:localhost:60
Last login: Mon Mar 11 17:20:35 2019 from 192.168.47.1
[root@peng ~]# ss -antl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 127.0.0.1:6080 *:*
LISTEN 0 128 127.0.0.1:8000 *:*
LISTEN 0 128 *:111 *:*
LISTEN 0 5 192.168.122.1:53 *:*
LISTEN 0 128 *:22 *:*
LISTEN 0 100 127.0.0.1:25 *:*
LISTEN 0 128 ::1:6080 :::*
LISTEN 0 128 ::1:8000 :::*
LISTEN 0 128 :::111 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
//配置nginx
[root@peng ~]# vim /etc/nginx/nginx.conf //删掉下面80后面的内容
...
server {
listen 80;
...
[root@peng ~]# vim /etc/nginx/conf.d/webvirtmgr.conf
server {
listen 80 default_server;
server_name $hostname;
#access_log /var/log/nginx/webvirtmgr_access_log;
location /static/ {
root /var/www/webvirtmgr/webvirtmgr;
expires max;
}
location / {
proxy_pass http://127.0.0.1:8000;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-for $proxy_add_x_forwarded_for;
proxy_set_header Host $host:$server_port;
proxy_set_header X-Forwarded-Proto $remote_addr;
proxy_connect_timeout 600;
proxy_read_timeout 600;
proxy_send_timeout 600;
client_max_body_size 1024M;
}
}
//确保bind绑定的是本机的8000端口
[root@peng ~]# vim /var/www/webvirtmgr/conf/gunicorn.conf.py
...
bind = '0.0.0.0:8000' //确保此处绑定的是本机的8000端口，这个在nginx配置中定义了，被代理的端口
backlog = 2048
...
//重启nginx
[root@peng ~]# systemctl restart nginx
[root@peng ~]# ss -antl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 127.0.0.1:6080 *:*
LISTEN 0 128 127.0.0.1:8000 *:*
LISTEN 0 128 *:111 *:*
LISTEN 0 128 *:80 *:*
LISTEN 0 5 192.168.122.1:53 *:*
LISTEN 0 128 *:22 *:*
LISTEN 0 100 127.0.0.1:25 *:*
LISTEN 0 128 ::1:6080 :::*
LISTEN 0 128 ::1:8000 :::*
LISTEN 0 128 :::111 :::*
LISTEN 0 128 :::80 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
//设置supervisor
[root@peng ~]# vim /etc/supervisord.conf //在最下面添加下面内容
...
[program:webvirtmgr]
command=/usr/bin/python2 /var/www/webvirtmgr/manage.py run_gunicorn -c /var/www/webvirtmgr/conf/gunicorn.conf.py
directory=/var/www/webvirtmgr
autostart=true
autorestart=true
logfile=/var/log/supervisor/webvirtmgr.log
log_stderr=true
user=nginx
[program:webvirtmgr-console]
command=/usr/bin/python2 /var/www/webvirtmgr/console/webvirtmgr-console
directory=/var/www/webvirtmgr
autostart=true
autorestart=true
stdout_logfile=/var/log/supervisor/webvirtmgr-console.log
redirect_stderr=true
user=nginx
//启动supervisor并设置开机自启
[root@peng ~]# systemctl start supervisord
[root@peng ~]# systemctl enable supervisord
[root@peng ~]# systemctl status supervisord
[root@peng ~]# ss -antl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 127.0.0.1:6080 *:*
LISTEN 0 128 127.0.0.1:8000 *:*
LISTEN 0 128 *:111 *:*
LISTEN 0 128 *:80 *:*
LISTEN 0 5 192.168.122.1:53 *:*
LISTEN 0 128 *:22 *:*
LISTEN 0 100 127.0.0.1:25 *:*
LISTEN 0 128 ::1:6080 :::*
LISTEN 0 128 ::1:8000 :::*
LISTEN 0 128 :::111 :::*
LISTEN 0 128 :::80 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
//配置nginx用户
[root@peng ~]# cd /home/
[root@peng home]# mkdir nginx
[root@peng home]# chown -R nginx.nginx nginx/
[root@peng home]# chmod -R 700 nginx/
[root@peng home]# su - nginx -s /bin/bash
-bash-4.2$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/var/lib/nginx/.ssh/id_rsa):
Created directory '/var/lib/nginx/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /var/lib/nginx/.ssh/id_rsa.
Your public key has been saved in /var/lib/nginx/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:1tO6H4QKgQ9vlcl1MTgkUQBYG12HdQ1OwqzMLc8fRlg nginx@peng
The key's randomart image is:
+---[RSA 2048]----+
| o+o+*=*B.+o |
| .. +.=+oo*E .|
| o o =o + o. |
| + o .=oo . |
| = S ++o. |
| . o . +o o |
| . . .o . |
| . .. |
| ... |
+----[SHA256]-----+
-bash-4.2$ touch ~/.ssh/config && echo -e "StrictHostKeyChecking=no\nUserKnownHostsFile=/dev/null" >> ~/.ssh/config
-bash-4.2$ chmod 0600 ~/.ssh/config
-bash-4.2$ ssh-copy-id [email protected]
/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/var/lib/nginx/.ssh/id_rsa.pub"
/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
Warning: Permanently added '192.168.47.128' (ECDSA) to the list of known hosts.
[email protected]'s password:
Number of key(s) added: 1
Now try logging into the machine, with: "ssh '[email protected]'"
and check to make sure that only the key(s) you wanted were added.
-bash-4.2$ exit
登出
[root@peng home]# vim /etc/polkit-1/localauthority/50-local.d/50-libvirt-remote-access.pkla
[root@peng ~]# cat /etc/polkit-1/localauthority/50-local.d/50-libvirt-remote-access.pkla
[Remote libvirt SSH access]
Identity=unix-user:root
Action=org.libvirt.unix.manage
ResultAny=yes
ResultInactive=yes
ResultActive=yes
[root@peng home]# cd
[root@peng ~]# chown -R root.root /etc/polkit-1/localauthority/50-local.d/50-libvirt-remote-access.pkla
[root@peng ~]# systemctl restart nginx
[root@peng ~]# systemctl restart libvirtd
3.3 kvm web界面管理
通过ip地址在浏览器上访问kvm，例如我这里就是：http://192.168.47.128/login
3.3.1 kvm连接管理
创建SSH连接：
3.3.2 kvm存储管理
创建存储：
进入存储：
通过xftp软件上传ISO镜像文件至存储目录/var/lib/libvirt/images/
[root@peng ~]# nginx
[root@peng ~]# cd /var/lib/libvirt/images/
[root@peng images]# ls
rhel-server-7.4-x86_64-dvd.iso
在 web 界面查看ISO镜像是否存在
创建系统安装镜像
点击添加镜像：
添加成功如下图所示
3.3.3 kvm网络管理
添加桥接网络
3.3.4 实例管理
实例(虚拟机)创建
设置在 web 上访问虚拟机的密码
启动虚拟机
虚拟机安装步骤就是安装系统的步骤，此处就不再赘述