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
3.1kvm安装
[[email protected] ~]# systemctl stop firewalld
[[email protected] ~]# systemctl disable firewalld
[[email protected] ~]# setenforce 0
[[email protected] ~]# sed -ri 's/^(SELINUX=).*/\1disabled/g' /etc/selinux/config
[[email protected] ~]# reboot
[[email protected] ~]# yum -y install epel-release vim wget net-tools unzip zip gcc gcc-c++
[[email protected] ~]# egrep -o 'vmx|svm' /proc/cpuinfo
vmx
vmx
[[email protected] ~]# 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
[email protected] network-scripts]# ls
ifcfg-ens33 ifdown-ipv6 ifdown-TeamPort ifup-ippp ifup-routes network-functions
ifcfg-lo ifdown-isdn ifdown-tunnel ifup-ipv6 ifup-sit network-functions-ipv6
ifdown ifdown-post ifup ifup-isdn ifup-Team
ifdown-bnep ifdown-ppp ifup-aliases ifup-plip ifup-TeamPort
ifdown-eth ifdown-routes ifup-bnep ifup-plusb ifup-tunnel
ifdown-ib ifdown-sit ifup-eth ifup-post ifup-wireless
ifdown-ippp ifdown-Team ifup-ib ifup-ppp init.ipv6-global
[[email protected] network-scripts]# cp ifcfg-ens33 ifcfg-br0
[[email protected] network-scripts]# vim ifcfg-br0
TYPE=Bridge
DEVICE=br0
NM_CONTROLLED=no
BOOTPROTO=static
NAME=br0
ONBOOT=yes
IPADDR=192.168.43.109
NETMASK=255.255.255.0
GATEWAY=192.168.43.184
DNS1=114.114.114.114
DNS2=8.8.8.8
[[email protected] ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens33
TYPE=Ethernet
BOOTPROTO=static
NAME=ens33
DEVICE=ens33
ONBOOT=yes
BRIDGE=br0
NM_CONTROLLED=no
[[email protected] ~]# systemctl restart network
[[email protected] ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
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 qlen 1000
link/ether 00:0c:29:ec:e1:b2 brd ff:ff:ff:ff:ff:ff
4: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP qlen 1000
link/ether 00:0c:29:ec:e1:b2 brd ff:ff:ff:ff:ff:ff
inet 192.168.43.109/24 brd 192.168.43.255 scope global br0
valid_lft forever preferred_lft forever
inet6 2409:894c:c36:7832:20c:29ff:feec:e1b2/64 scope global mngtmpaddr dynamic
valid_lft 3463sec preferred_lft 3463sec
inet6 fe80::20c:29ff:feec:e1b2/64 scope link
valid_lft forever preferred_lft forever
[[email protected] ~]# systemctl start libvirtd
[[email protected] ~]# systemctl enable libvirtd
[[email protected] ~]# lsmod|grep kvm
kvm_intel 170086 0
kvm 566340 1 kvm_intel
irqbypass 13503 1 kvm
[[email protected] ~]# virsh -c qemu:///system list
Id 名称 状态
----------------------------------------------------
[[email protected] ~]# virsh --version
4.5.0
[[email protected] ~]# virt-install --version
1.5.0
[[email protected] ~]# ln -s /usr/libexec/qemu-kvm /usr/bin/qemu-kvm
[[email protected] ~]# ll /usr/bin/qemu-kvm
lrwxrwxrwx 1 root root 21 3月 11 17:45 /usr/bin/qemu-kvm -> /usr/libexec/qemu-kvm
[[email protected] ~]# lsmod |grep kvm
kvm_intel 170086 0
kvm 566340 1 kvm_intel
irqbypass 13503 1 kvm
[[email protected] ~]# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.000c29ece1b2 no ens33
virbr0 8000.5254004841a0 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。
[[email protected] ~]# yum -y install git python-pip libvirt-python libxml2-python python-websockify supervisor nginx python-devel
//升级pip
[[email protected] ~]# pip install --upgrade pip
//从github上下载webvirtmgr代码
[[email protected] ~]# cd /usr/local/src/
[[email protected] src]# git clone git://github.com/retspen/webvirtmgr.git
//安装webvirtmgr
[[email protected] src]# cd webvirtmgr/
[[email protected] webvirtmgr]# pip install -r requirements.txt
//检查sqlite3是否安装
[[email protected] webvirtmgr]# python
>>> import sqlite3
>>> exit()
//初始化帐号信息
[[email protected] webvirtmgr]# python manage.py syncdb
//拷贝web网页至指定目录
[[email protected] webvirtmgr]# mkdir /var/www
[[email protected] webvirtmgr]# cp -r /usr/local/src/webvirtmgr /var/www/
[[email protected] webvirtmgr]# chown -R nginx.nginx /var/www/webvirtmgr/
//生成**
[[email protected] ~]# ssh-****** -t rsa
The key's randomart image is:
+---[RSA 2048]----+
| o |
| ..+. |
|..+o . |
|o+.o + . . |
|+*. = . S |
|+E+o . |
|+*= + . |
|BO+===. |
|Oo=**= |
+----[SHA256]-----+
[[email protected] ~]# ssh-copy-id 192.168.137.131
//配置端口转发
[[email protected] ~]# ssh 192.168.137.131 -L localhost:8000:localhost:8000 -L localhost:6080:localhost:60
[[email protected] ~]# ss -antl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
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 0 128 127.0.0.1:6080 *:*
LISTEN 0 128 127.0.0.1:8000 *:*
LISTEN 0 128 :::111 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
LISTEN 0 128 ::1:6080 :::*
LISTEN 0 128 ::1:8000 :::*
//配置nginx
[[email protected] ~]# vim /etc/nginx/nginx.conf
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;
include /usr/share/nginx/modules/*.conf;
events {
worker_connections 1024;
}
http {
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
access_log /var/log/nginx/access.log main;
sendfile on;
tcp_nopush on;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 2048;
include /etc/nginx/mime.types;
default_type application/octet-stream;
include /etc/nginx/conf.d/*.conf;
server {
listen 80;
server_name localhost;
include /etc/nginx/default.d/*.conf;
location / {
root html;
index index.html index.htm;
}
error_page 404 /404.html;
location = /40x.html {
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
}
}
}
[[email protected] ~]# 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
[[email protected] ~]# 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
[[email protected] ~]# systemctl restart nginx
[[email protected] ~]# ss -antl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
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 0 128 127.0.0.1:6080 *:*
LISTEN 0 128 127.0.0.1:8000 *:*
LISTEN 0 128 :::111 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
LISTEN 0 128 ::1:6080 :::*
LISTEN 0 128 ::1:8000 :::*
//设置supervisor
[[email protected] ~]# 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
[[email protected] ~]# systemctl start supervisord
[[email protected] ~]# systemctl enable supervisord
Created symlink from /etc/systemd/system/multi-user.target.wants/supervisord.service to /usr/lib/systemd/system/supervisord.service.
[[email protected] ~]# systemctl status supervisord
[[email protected] webvirtmgr]# ss -antl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
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 *:8000 *:*
LISTEN 0 100 *:6080 *:*
LISTEN 0 128 :::111 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
//配置nginx用户
[[email protected] ~]# cd /home/
[[email protected] home]# mkdir nginx
[[email protected] home]# chown -R nginx.nginx nginx/
[[email protected] home]# chmod -R 700 nginx/
[[email protected] home]# su - nginx -s /bin/bash
-bash-4.2$ ssh-****** -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:rdbmW/YIXxAJBzPsd9q9eKHPjWtSZ5EQC5li3tkczYI [email protected]
The key's randomart image is:
+---[RSA 2048]----+
| .=o=.+ |
| o.E.=.o |
| o.o *.+ .|
| o.o.+.o |
| S ...+ ..|
| o ..o.+|
| o + o.+oo|
| . o =.*o+.|
| o.oo*+.|
+----[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]
[email protected]'s password:
Number of key(s) added: 1
-bash-4.2$ exit
logout
[[email protected] ~]# vim /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
[[email protected] ~]# chown -R root.root /etc/polkit-1/localauthority/50-local.d/50-libvirt-remote-access.pkla
[[email protected] ~]# systemctl restart nginx
[[email protected] ~]# systemctl restart libvirtd