KVM虚拟化
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。
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
KVM安装
关闭防火墙selinux
[root@localhost ~]# systemctl disable --now firewalld
Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
[root@localhost ~]# vim /etc/selinux/config
[root@localhost ~]# reboot
[root@localhost ~]# getenforce 0
Disabled
配置网络源
[root@localhost ~]# cd /etc/yum.repos.d/
[root@localhost yum.repos.d]# curl -o /etc/yum.repos.d/CentOS7-Base-163.repo http://mirrors.163.com/.help/CentOS7-Base-163.repo
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 1572 100 1572 0 0 2019 0 --:--:-- --:--:-- --:--:-- 2017
[root@localhost yum.repos.d]# sed -i 's/\$releasever/7/g' /etc/yum.repos.d/CentOS7-Base-163.repo
[root@localhost yum.repos.d]# sed -i 's/^enabled=.*/enabled=1/g' /etc/yum.repos.d/CentOS7-Base-163.repo
[root@localhost yum.repos.d]# yum -y install epel-release vim wget net-tools unzip zip gcc gcc-c++
验证CPU是否支持KVM
[root@localhost ~]# egrep -o 'vmx|svm' /proc/cpuinfo
vmx
vmx
vmx
vmx
kvm安装
[root@localhost ~]# yum -y install qemu-kvm qemu-kvm-common qemu-img virt-manager libvirt python3-libvirt libvirt-client virt-install virt-viewer bridge-utils libguestfs-tools
[root@localhost ~]# cd /etc/sysconfig/network-scripts
[root@localhost network-scripts]# ls
ifcfg-ens33 ifdown-isdn ifup ifup-plip ifup-tunnel
ifcfg-lo ifdown-post ifup-aliases ifup-plusb ifup-wireless
ifdown ifdown-ppp ifup-bnep ifup-post init.ipv6-global
ifdown-bnep ifdown-routes ifup-eth ifup-ppp network-functions
ifdown-eth ifdown-sit ifup-ib ifup-routes network-functions-ipv6
ifdown-ib ifdown-Team ifup-ippp ifup-sit
ifdown-ippp ifdown-TeamPort ifup-ipv6 ifup-Team
ifdown-ipv6 ifdown-tunnel ifup-isdn ifup-TeamPort
[root@localhost network-scripts]# cp ifcfg-ens33 ifcfg-br0
[root@localhost network-scripts]# cat ifcfg-br0
TYPE="Bridge"
BOOTPROTO="static"
DEVICE="br0"
NAME="br0"
ONBOOT="yes"
IPADDR=192.168.145.149
GATEWAY=192.168.145.2
NETMASK=255.255.255.0
DNS1=192.168.145.2
DNS2=114.114.114.114
[root@localhost network-scripts]# cat ifcfg-ens33
TYPE="Ethernet"
BOOTPROTO="static"
DEVICE="ens33"
NAME="ens33"
ONBOOT="yes"
BRIDGE="br0"
重启网络
[root@localhost ~]# systemctl restart network
[root@localhost ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> 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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br0 state UP group default qlen 1000
link/ether 00:0c:29:20:9e:66 brd ff:ff:ff:ff:ff:ff
3: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 00:0c:29:20:9e:66 brd ff:ff:ff:ff:ff:ff
inet 192.168.145.149/24 brd 192.168.145.255 scope global noprefixroute br0
valid_lft forever preferred_lft forever
inet6 fe80::387d:daff:fe6b:c9c1/64 scope link
valid_lft forever preferred_lft forever
启动服务并设置开机自启
[root@localhost ~]# systemctl start libvirtd
[root@localhost ~]# systemctl enable libvirtd
[root@localhost ~]# systemctl status libvirtd
● libvirtd.service - Virtualization daemon
Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled; vendor preset: enabled)
Active: active (running) since 三 2021-10-20 12:16:29 EDT; 9s ago
Docs: man:libvirtd(8)
https://libvirt.org
Main PID: 20714 (libvirtd)
CGroup: /system.slice/libvirtd.service
├─20714 /usr/sbin/libvirtd
├─20825 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default....
└─20826 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default....
10月 20 12:16:29 localhost.localdomain dnsmasq[20825]: started, version 2.76 cach...
10月 20 12:16:29 localhost.localdomain dnsmasq[20825]: compile time options: IPv6...
10月 20 12:16:29 localhost.localdomain dnsmasq-dhcp[20825]: DHCP, IP range 192.16...
10月 20 12:16:29 localhost.localdomain dnsmasq-dhcp[20825]: DHCP, sockets bound e...
10月 20 12:16:29 localhost.localdomain dnsmasq[20825]: reading /etc/resolv.conf
10月 20 12:16:29 localhost.localdomain dnsmasq[20825]: using nameserver 192.168.1...
10月 20 12:16:29 localhost.localdomain dnsmasq[20825]: using nameserver 114.114.1...
10月 20 12:16:29 localhost.localdomain dnsmasq[20825]: read /etc/hosts - 2 addresses
10月 20 12:16:29 localhost.localdomain dnsmasq[20825]: read /var/lib/libvirt/dnsm...
10月 20 12:16:29 localhost.localdomain dnsmasq-dhcp[20825]: read /var/lib/libvirt...
Hint: Some lines were ellipsized, use -l to show in full
验证
[root@localhost ~]# lsmod|grep kvm
kvm_intel 174841 0
kvm 578518 1 kvm_intel
irqbypass 13503 1 kvm
测试验证安装结果
[root@localhost ~]# virsh -c qemu:///system list
Id 名称 状态
----------------------------------------------------
[root@localhost ~]# virsh --version
4.5.0
[root@localhost ~]# virt-install --version
1.5.0
[root@localhost ~]# ln -s /usr/libexec/qemu-kvm /usr/bin/qemu-kvm
[root@localhost ~]# ll /usr/bin/qemu-kvm
lrwxrwxrwx 1 root root 21 10月 20 12:18 /usr/bin/qemu-kvm -> /usr/libexec/qemu-kvm
[root@localhost ~]# lsmod |grep kvm
kvm_intel 174841 0
kvm 578518 1 kvm_intel
irqbypass 13503 1 kvm
查看网桥
[root@localhost ~]# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.000c29209e66 no ens33
virbr0 8000.525400b57dfe yes virbr0-nic
KVM web界面安装
安装依赖包
[root@localhost ~]# yum -y install git python-pip libvirt-python libxml2-python python-we
安装webvirtmgr
拉取
[root@localhost ~]# cd /usr/local/src/
[root@localhost 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), 2.97 MiB | 87.00 KiB/s, done.
处理 delta 中: 100% (3606/3606), done.
安装
[root@localhost src]# cd webvirtmgr/
[root@localhost webvirtmgr]# pip2 install -r requirements.txt
Collecting django==1.5.5 (from -r requirements.txt (line 1))
Downloading https://files.pythonhosted.org/packages/38/49/93511c5d3367b6b21fc2995a0e53399721afc15e4cd6eb57be879ae13ad4/Django-1.5.5.tar.gz (8.1MB)
100% |████████████████████████████████| 8.1MB 114kB/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 3.8MB/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
Found existing installation: Django 1.11.27
Uninstalling Django-1.11.27:
Successfully uninstalled Django-1.11.27
Running setup.py install for django ... done
Successfully installed django-1.5.5 gunicorn-19.5.0 lockfile-0.12.2
You are using pip version 8.1.2, however version 21.3 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
检查sqlite3是否安装
[root@localhost ~]# python
Python 2.7.5 (default, Nov 16 2020, 22:23:17)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-44)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> exit
Use exit() or Ctrl-D (i.e. EOF) to exit
>>> exit()
[root@localhost ~]# cd /usr/local/src/webvirtmgr/
[root@localhost 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
Username (leave blank to use 'root'): root
Email address: 1642453107@qq.com
Password:
Password (again):
Superuser created successfully.
Installing custom SQL ...
Installing indexes ...
Installed 6 object(s) from 1 fixture(s)
创建用户
[root@localhost ~]# useradd nginx
[root@localhost webvirtmgr]# cp -r /usr/local/src/webvirtmgr /var/www/
[root@localhost webvirtmgr]# chown -R nginx.nginx /var/www/webvirtmgr/
[root@localhost ~]# 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:IoSeB6UcXBTiYTlUOCjORkc/HZ+luwS8t5jXadtfoyE root@localhost.localdomain
The key's randomart image is:
+---[RSA 2048]----+
| +BB*. . . |
|o=*O. o o + |
|= Bo.o + + |
| = + . o . |
|. o o ..S+ |
| . . .= + . |
| o + E . ..|
| . . + o o|
| . o.. |
+----[SHA256]-----+
[root@localhost ~]# ssh-copy-id 192.168.145.149
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.145.149 (192.168.145.149)' can't be established.
ECDSA key fingerprint is SHA256:M0xtpozXpCsgJ3Fwqlvqqx7bmIF8wXeYP6MbJxx6ftQ.
ECDSA key fingerprint is MD5:32:fd:62:4d:03:16:2a:38:22:ce:86:ed:68:45:ee:2c.
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
root@192.168.145.149's password:
Number of key(s) added: 1
Now try logging into the machine, with: "ssh '192.168.145.149'"
and check to make sure that only the key(s) you wanted were added.
配置端口转发
[root@localhost ~]# ssh 192.168.145.149 -L localhost:8000:localhost:8000 -L localhost:6080:localhost:60
Last login: Wed Oct 20 11:59:26 2021 from 192.168.145.1
[root@localhost ~]# ss -antl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 5 127.0.0.1:25151 *:*
LISTEN 0 128 127.0.0.1:6080 *:*
LISTEN 0 128 127.0.0.1:8000 *:*
LISTEN 0 5 *:873 *:*
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 5 :::873 :::*
LISTEN 0 128 :::80 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
LISTEN 0 128 :::443 :::*
安装nginx
[root@localhost ~]# yum -y install nginx
[root@localhost nginx]# vim nginx.conf
server {
listen 80;
server_name localhost;
# Load configuration files for the default server block.
include /etc/nginx/default.d/*.conf;
error_page 404 /404.html;
location = /404.html {
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
}
}
[root@localhost nginx]# cd conf.d/
[root@localhost conf.d]# cat 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;
}
}
[root@localhost ~]# vim /var/www/webvirtmgr/conf/gunicorn.conf.py
bind = '0.0.0.0:8000'
backlog = 2048
重启nginx
[root@localhost ~]# systemctl restart nginx
[root@localhost ~]# ss -anlt
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 *: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 :::22 :::*
LISTEN 0 100 ::1:25
设置supervisor
[root@localhost ~]# yum -y install supervisor
[root@localhost ~]# vim /etc/supervisord.conf
[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@localhost ~]# systemctl start supervisord
[root@localhost ~]# systemctl enable supervisord
Created symlink from /etc/systemd/system/multi-user.target.wants/supervisord.service to /usr/lib/systemd/system/supervisord.service.
[root@localhost ~]# systemctl status supervisord
● supervisord.service - Process Monitoring and Control Daemon
Loaded: loaded (/usr/lib/systemd/system/supervisord.service; enabled; vendor preset: disabled)
Active: active (running) since 三 2021-10-20 14:07:13 EDT; 27s ago
Main PID: 9379 (supervisord)
CGroup: /system.slice/supervisord.service
├─9379 /usr/bin/python /usr/bin/supervisord -c /etc/supervisord.conf
├─9407 /usr/bin/python2 /var/www/webvirtmgr/manage.py run_gunicorn -c /...
├─9413 /usr/bin/python2 /var/www/webvirtmgr/manage.py run_gunicorn -c /...
├─9414 /usr/bin/python2 /var/www/webvirtmgr/manage.py run_gunicorn -c /...
├─9415 /usr/bin/python2 /var/www/webvirtmgr/manage.py run_gunicorn -c /...
├─9416 /usr/bin/python2 /var/www/webvirtmgr/manage.py run_gunicorn -c /...
├─9417 /usr/bin/python2 /var/www/webvirtmgr/manage.py run_gunicorn -c /...
├─9418 /usr/bin/python2 /var/www/webvirtmgr/manage.py run_gunicorn -c /...
├─9433 /usr/bin/python2 /var/www/webvirtmgr/manage.py run_gunicorn -c /...
├─9434 /usr/bin/python2 /var/www/webvirtmgr/manage.py run_gunicorn -c /...
└─9435 /usr/bin/python2 /var/www/webvirtmgr/manage.py run_gunicorn -c /...
10月 20 14:07:13 localhost.localdomain systemd[1]: Starting Process Monitoring a....
10月 20 14:07:13 localhost.localdomain systemd[1]: Started Process Monitoring an....
Hint: Some lines were ellipsized, use -l to show in full.
[root@localhost ~]# 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 *: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 :::22 :::*
LISTEN 0 100 ::1:25 :::*
配置nginx用户
[root@localhost ~]# su - nginx -s /bin/bash
[nginx@localhost ~]$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/nginx/.ssh/id_rsa):
Created directory '/home/nginx/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/nginx/.ssh/id_rsa.
Your public key has been saved in /home/nginx/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:XxALcN/JGzD4p0gGtt8wBtcSePxK0Ug+kdeDaPZAm1k nginx@localhost.localdomain
The key's randomart image is:
+---[RSA 2048]----+
| .*BOEo |
| =o#O=Bo. |
| . O*O+ =. |
| . B.+..o |
| *S* oo |
| +.o. |
| . |
| |
| |
+----[SHA256]-----+
[nginx@localhost ~]$ touch ~/.ssh/config && echo -e "StrictHostKeyChecking=no\nUserKnownHostsFile=/dev/null" >> ~/.ssh/config
[nginx@localhost ~]$ chmod 0600 ~/.ssh/config
[nginx@localhost ~]$ ssh-copy-id root@192.168.145.149
/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/home/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 '192.168.145.149' (ECDSA) to the list of known hosts.
root@192.168.145.149's password:
Number of key(s) added: 1
Now try logging into the machine, with: "ssh 'root@192.168.145.149'"
and check to make sure that only the key(s) you wanted were added.
[nginx@localhost ~]$ exit
logout
[root@localhost ~]# vim /etc/polkit-1/localauthority/50-local.d/50-libvirt-remote-access.pkla
[root@localhost ~]# 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@localhost ~]# systemctl restart nginx
[root@localhost ~]# systemctl restart libvirtd
[root@localhost ~]# cd /var/lib/libvirt/images/ [root@localhost images]# ls [root@localhost images]# ls CentOS-8.4.2105-x86_64-dvd1.iso