虚拟化介绍
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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。
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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）。
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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：
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全虚拟化
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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
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kVM 全称是 Kernel-Based Virtual Machine。也就是说 KVM 是基于 Linux 内核实现的。
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KVM有一个内核模块叫 kvm.ko，只用于管理虚拟 CPU 和内存。
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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。
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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。
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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。
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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。
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Libvirt 包含 3 个东西：后台 daemon 程序 libvirtd、API 库和命令行工具 virsh
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libvirtd是服务程序，接收和处理 API 请求；
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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；
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virsh 是我们经常要用的 KVM 命令行工具
kvm部署
- 环境说明
| 系统类型 | ip地址 |
|---|---|
| RHEL7 | 192.168.170.13 |
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kvm安装
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部署前请确保你的CPU虚拟化功能已开启。分为两种情况：
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虚拟机要关机设置CPU虚拟化
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物理机要在BIOS里开启CPU虚拟化
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关闭防火墙与SELINUX
[root@kvm ~]# systemctl stop firewalld
[root@kvm ~]# 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@kvm ~]# setenforce 0
[root@kvm ~]# sed -ri 's/^(SELINUX=).*/\1disabled/g' /etc/selinux/config
[root@localhost ~]# reboot
- 配置网络源
[root@localhost ~]# 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 17810 0 --:--:-- --:--:-- --:--:-- 17662
[root@localhost ~]# sed -i 's/\$releasever/7/g' /etc/yum.repos.d/CentOS7-Base-163.repo
[root@localhost ~]# sed -i 's/^enabled=.*/enabled=1/g' /etc/yum.repos.d/CentOS7-Base-163.repo
- 安装依赖包、工具
[root@kvm ~]# 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@localhost ~]# egrep -o 'vmx|svm' /proc/cpuinfo
vmx
[root@localhost ~]#
- kvm安装
[root@localhost ~]#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
……
安装过程省略
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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ens33，所以用br0来桥接ens33网卡
[root@localhost network-scripts]# cp ifcfg-ens33 ifcfg-br0
[root@localhost network-scripts]# ls
ifcfg-br0 ifdown-ippp ifdown-Team ifup-ib ifup-ppp init.ipv6-global
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
[root@localhost network-scripts]#
[root@localhost network-scripts]# vim ifcfg-br0
[root@localhost network-scripts]# cat ifcfg-br0
[root@localhost ~]# cat /etc/sysconfig/network-scripts/ifcfg-br0
TYPE=Bridge
DEVICE=br0
NM_CONTROLLED=no
BOOTPROTO=static
NAME=br0
ONBOOT=yes
IPADDR=192.168.170.13
NETMASK=255.255.255.0
GATEWAY=192.168.170.2
DNS1=114.114.114.114
DNS2=8.8.8.8
[root@localhost ~]#
[root@localhost network-scripts]#
[root@localhost ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens33
TYPE=Ethernet
BOOTPROTO=static
NAME=ens33
DEVICE=ens33
ONBOOT=yes
BRIDGE=br0
NM_CONTROLLED=no
- 重启网络
[root@localhost ~]#
[root@localhost ~]# /etc/init.d/network restart
Restarting network (via systemctl): [ ok ]
[root@localhost ~]#
- 启动服务
[root@localhost ~]# systemctl start libvirtd
[root@localhost ~]# systemctl enable libvirtd
- 验证安装结果
[root@localhost ~]# lsmod|grep kvm
kvm_intel 170086 0
kvm 566340 1 kvm_intel
irqbypass 13503 1 kvm
- 测试并验证安装结果
[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 ~]#
[root@localhost ~]# ln -s /usr/libexec/qemu-kvm /usr/bin/qemu-kvm
[root@localhost ~]# ll /usr/bin/qemu-kvm
lrwxrwxrwx 1 root root 21 8月 31 12:09 /usr/bin/qemu-kvm -> /usr/libexec/qemu-kvm
- 查看网卡信息
[root@localhost ~]# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.000c292184e7 no ens33
virbr0 8000.525400585a5f yes virbr0-nic
[root@localhost ~]#
- 使用xmanaer管理，掉出界面 kvm
web管理界面安装
- 安装依赖包
[root@localhost ~]# yum -y install git python-pip libvirt-python libxml2-python python-websockify supervisor nginx python-devel
- 升级pip
[root@localhost ~]#pip install --upgrade pip
- 从github上下载webvirtmgr代码
[root@localhost ~]#cd /usr/local/src/
[root@localhost src]#git clone git://github.com/retspen/webvirtmgr.git
Cloning into 'webvirtmgr'...
remote: Enumerating objects: 5730, done.
remote: Total 5730 (delta 0), reused 0 (delta 0), pack-reused 5730
Receiving objects: 100% (5730/5730), 3.01 MiB | 39.00 KiB/s, done.
Resolving deltas: 100% (3688/3688), done.
- 安装webvirtmgr
[root@localhost src]#cd webvirtmgr/
[root@localhost webvirtmgr]# pip 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)
57% |██████████████████▌ | 4.7MB 38kB/s eta 0:01:28
.....此处省略安装步骤
- 检查sqlite3是否安装
[root@localhost webvirtmgr]# python
Python 2.7.5 (default, May 3 2017, 07:55:04)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-14)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import sqlite3
>>> exit()
- 初始化帐号信息
[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 //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@localhost webvirtmgr]# mkdir /var/www
[root@localhost webvirtmgr]#cp -r /usr/local/src/webvirtmgr /var/www/
[root@localhost webvirtmgr]#chown -R nginx.nginx /var/www/webvirtmgr/
- 生成密钥
[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:CQoZtso2M5Uo39lKvjZboncqakQ69iJt5wnjiJKZNhw root@kvm
The key's randomart image is:
+---[RSA 2048]----+
| o |
| ..+. |
|..+o . |
|o+.o + . . |
|+*. = . S |
|+E+o . |
|+*= + . |
|BO+===. |
|Oo=**= |
+----[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ip
[root@localhost ~]#ssh-copy-id 192.168.170.13
- 配置端口转发
[root@localhost ~]#ssh 192.168.100.13 -L localhost:8000:localhost:8000 -L localhost:6080:localhost:60
[root@localhost~]# 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
[root@localhost ~]#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 {
}
}
}
[root@kvm ~]# 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 $remote_addr;
proxy_connect_timeout 600;
proxy_read_timeout 600;
proxy_send_timeout 600;
client_max_body_size 1024M;
}
}
- 确保bind绑定的是本机的8000端口
[root@localhost ~]# vim /var/www/webvirtmgr/conf/gunicorn.conf.py
.....此处省略N行
bind = '0.0.0.0:8000' //确保此处绑定的是本机的8000端口，这个在nginx配置中定义了，被代理的端口
backlog = 2048
.....此处省略N行
- 重启nginx
[root@localhost ~]#systemctl restart nginx
[root@localhost ~]#ss -antl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 *:111 *:*
LISTEN 0 128 *:80 *:*
LISTEN 0 5 192.168.122.1:53 *:*
LISTEN 0 128 *:22 *:*
LISTEN 0 100 127.0.0.1:25 *:*
LISTEN 0 128 127.0.0.1:6080 *:*
LISTEN 0 128 127.0.0.1:8000 *:*
LISTEN 0 128 :::111 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
LISTEN 0 128 ::1:6080 :::*
LISTEN 0 128 ::1:8000 :::*
- 设置supervisor
[root@localhost ~]#vim /etc/supervisord.conf
.....此处省略上面的内容，在文件最后加上以下内容
[program:webvirtmgr]
command=/usr/bin/python2 /var/www/webvirtmgr/manage.py run_gunicorn -c /var/www/webvirtmgr/conf/gunicorn.conf.py
directory=/var/www/webvirtmgr
autostart=true
autorestart=true
logfile=/var/log/supervisor/webvirtmgr.log
log_stderr=true
user=nginx
[program:webvirtmgr-console]
command=/usr/bin/python2 /var/www/webvirtmgr/console/webvirtmgr-console
directory=/var/www/webvirtmgr
autostart=true
autorestart=true
stdout_logfile=/var/log/supervisor/webvirtmgr-console.log
redirect_stderr=true
user=nginx
- 启动supervisor并设置开机自启
[root@localhost ~]#systemctl start supervisord
[root@localhost ~]#systemctl enable supervisord
[root@localhost ~]#systemctl status supervisord
```
- 配置nginx用户
```
[root@localhost ~]# su - nginx -s /bin/bash
-bash-4.2$ 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: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]
/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 '192.168.160.109' (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
logout
[root@localhost ~]# 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
[root@localhost ~]# chown -R root.root /etc/polkit-1/localauthority/50-local.d/50-libvirt-remote-access.pkla
[root@localhost ~]# systemctl restart nginx
[root@localhost ~]# systemctl restart libvirtd
```
## 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://192.168.170.13
