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:
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 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
部署前请确保你的CPU虚拟化功能已开启。分为两种情况:
//关闭防火墙与SELINUX
[root@localhost ~]# systemctl stop firewalld
[root@localhost ~]# 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@localhost ~]# setenforce 0
[root@localhost ~]# sed -ri 's/^(SELINUX=).*/\1disabled/g' /etc/selinux/config
[root@localhost ~]# reboot
//配置网络源
[root@localhost yum.repos.d]# curl -o /etc/yum.repos.d/CentOS7-Base-163.repo http://mirrors.163.com/.help/CentOS7-Base-163.repo
[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
[root@localhost ~]# yum -y install epel-release vim wget net-tools unzip zip gcc gcc-c++
//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 yum.repos.d]# egrep -o 'vmx|svm' /proc/cpuinfo
vmx
vmx
vmx
vmx
//kvm安装
[root@localhost yum.repos.d]# 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
//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 yum.repos.d]# cd /etc/sysconfig/network-scripts/
[root@localhost network-scripts]# cp ifcfg-ens33 ifcfg-br0
[root@localhost network-scripts]# cat ifcfg-br0
TYPE=Bridge
BOOTPROTO=static
NAME=br0
DEVICE=br0
ONBOOT=yes
NM_CONTROLLED=no
IPADDR=192.168.137.200
NETMAK=255.255.255.0
GATEWAY=192.168.137.1
DNS1=8.8.8.8
[root@localhost network-scripts]# cat ifcfg-ens33
TYPE=Ethernet
BOOTPROTO=static
NAME=ens33
DEVICE=ens33
ONBOOT=yes
BRIDGE=br0
NM_CONTROLLED=no
//重启网络
[root@localhost ~]# systemctl restart network
[root@localhost ~]# ip a
1: lo: 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: mtu 1500 qdisc pfifo_fast master br0 state UP qlen 1000
link/ether 00:0c:29:eb:50:f0 brd ff:ff:ff:ff:ff:ff
inet6 fe80::20c:29ff:feeb:50f0/64 scope link
valid_lft forever preferred_lft forever
4: br0: mtu 1500 qdisc noqueue state UP qlen 1000
link/ether 00:0c:29:eb:50:f0 brd ff:ff:ff:ff:ff:ff
inet 192.168.137.200/24 brd 192.168.137.255 scope global br0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:feeb:50f0/64 scope link
valid_lft forever preferred_lft forever
//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 ~]# ln -s /usr/libexec/qemu-kvm /usr/bin/qemu-kvm
[root@localhost ~]# ll /usr/bin/qemu-kvm
lrwxrwxrwx. 1 root root 21 3月 11 18:54 /usr/bin/qemu-kvm -> /usr/libexec/qemu-kvm
//查看网桥信息
[root@localhost ~]# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.000c29eb50f0 no ens33
virbr0 8000.525400840c6e yes virbr0-nic
kvm 的 web 管理界面是由 webvirtmgr 程序提供的
//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
//安装webvirtmgr
[root@localhost src]# cd webvirtmgr/
[root@localhost webvirtmgr]# pip install -r requirements.txt
//检查sqlite3是否安装
[root@localhost 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@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: //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:lkP4fX4wUdRCGw2Z9aye/gKyC+eh4LcQivZg9E86Yi4 [email protected]
The key's randomart image is:
+---[RSA 2048]----+
| o*B.|
| . .+++|
| . . . ..o|
| o o . . |
| . . S . + . |
| . o . o ..o.+ . |
| = o + . oo..+ |
|Eooo.= o.=.. o. |
| +..o.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@localhost ~]# ssh-copy-id 192.168.137.200
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.137.200 (192.168.137.200)' can't be established.
ECDSA key fingerprint is SHA256:SQixfZHiyRdLQriKljJZ0foZsWgdf8Pl897NJVGPiH8.
ECDSA key fingerprint is MD5:15:35:92:3d:96:66:77:dc:e7:0a:62:af:ae:b7:30:54.
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 '192.168.137.200'"
and check to make sure that only the key(s) you wanted were added.
//配置端口转发
[root@localhost ~]# ssh 192.168.137.200 -L localhost:8000:localhost:8000 -L localhost:6080:localhost:60
Last login: Mon Mar 11 18:36:47 2019 from 192.168.137.239
//配置nginx
[root@localhost ~]# vim /etc/nginx/nginx.conf
[root@localhost ~]# cat /etc/nginx/nginx.conf
# For more information on configuration, see:
# * Official English Documentation: http://nginx.org/en/docs/
# * Official Russian Documentation: http://nginx.org/ru/docs/
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;
# Load dynamic modules. See /usr/share/nginx/README.dynamic.
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;
# Load modular configuration files from the /etc/nginx/conf.d directory.
# See http://nginx.org/en/docs/ngx_core_module.html#include
# for more information.
include /etc/nginx/conf.d/*.conf;
server {
listen 80 ;
listen [::]:80 default_server;
server_name _;
root /usr/share/nginx/html;
# Load configuration files for the default server block.
include /etc/nginx/default.d/*.conf;
location / {
}
error_page 404 /404.html;
location = /40x.html {
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
}
}
# Settings for a TLS enabled server.
#
# server {
# listen 443 ssl http2 default_server;
# listen [::]:443 ssl http2 default_server;
# server_name _;
# root /usr/share/nginx/html;
#
# ssl_certificate "/etc/pki/nginx/server.crt";
# ssl_certificate_key "/etc/pki/nginx/private/server.key";
# ssl_session_cache shared:SSL:1m;
# ssl_session_timeout 10m;
# ssl_ciphers HIGH:!aNULL:!MD5;
# ssl_prefer_server_ciphers on;
#
# # Load configuration files for the default server block.
# include /etc/nginx/default.d/*.conf;
#
# location / {
# }
#
# error_page 404 /404.html;
# location = /40x.html {
# }
#
# error_page 500 502 503 504 /50x.html;
# location = /50x.html {
# }
# }
}
[root@localhost ~]# vim /etc/nginx/conf.d/webvirtmgr.conf
[root@localhost ~]# cat /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 $remote_addr;
proxy_connect_timeout 600;
proxy_read_timeout 600;
proxy_send_timeout 600;
client_max_body_size 1024M;
}
}
//确保bind绑定的是本机的8000端口
[root@localhost ~]# vim /var/www/webvirtmgr/conf/gunicorn.conf.py
.....此处省略N行
bind = '0.0.0.0:8000' //确保此处绑定的是本机的8000端口,这个在nginx配置中定义了,被代理的端口
backlog = 2048
.....此处省略N行
//重启nginx
[root@localhost ~]# systemctl restart nginx
[root@localhost ~]# ss -antl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 *:111 *:*
LISTEN 0 128 *:80 *:*
LISTEN 0 5 192.168.122.1:53 *:*
LISTEN 0 128 *:22 *:*
LISTEN 0 100 127.0.0.1:25 *:*
LISTEN 0 128 127.0.0.1:6080 *:*
LISTEN 0 128 127.0.0.1:8000 *:*
LISTEN 0 128 :::111 :::*
LISTEN 0 128 :::80 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
LISTEN 0 128 ::1:6080 :::*
LISTEN 0 128 ::1:8000 :::*
//设置supervisor
[root@localhost ~]# vim /etc/supervisord.conf
.....此处省略上面的内容,在文件最后加上以下内容
[program:webvirtmgr]
command=/usr/bin/python2 /var/www/webvirtmgr/manage.py run_gunicorn -c /var/www/webvirtmgr/conf/gunicorn.conf.py
directory=/var/www/webvirtmgr
autostart=true
autorestart=true
logfile=/var/log/supervisor/webvirtmgr.log
log_stderr=true
user=nginx
[program:webvirtmgr-console]
command=/usr/bin/python2 /var/www/webvirtmgr/console/webvirtmgr-console
directory=/var/www/webvirtmgr
autostart=true
autorestart=true
stdout_logfile=/var/log/supervisor/webvirtmgr-console.log
redirect_stderr=true
user=nginx
//启动supervisor并设置开机自启
[root@localhost ~]# systemctl start supervisord
[root@localhost ~]# systemctl enable supervisord
//配置nginx用户
[root@localhost ~]# cd /home/
[root@localhost home]# mkdir nginx
[root@localhost home]# chown -R nginx.nginx nginx/
[root@localhost home]# chmod -R 700 nginx/
[root@localhost home]# su - nginx -s /bin/bash
-bash-4.2$ 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:x7kPcKMisXzj7XvdRXYevDJOCk0RDE0o0dYl2GC5drE [email protected]
The key's randomart image is:
+---[RSA 2048]----+
| .o+%+o. |
| ..* B. |
| o . + . |
| + E o+|
| . S X ++|
| . 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 '192.168.137.200' (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@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 home]# chown -R root.root /etc/polkit-1/localauthority/50-local.d/50-libvirt-remote-access.pkla
[root@localhost home]# systemctl restart nginx
[root@localhost home]# systemctl restart libvirtd
//登入不了,就执行以下命令
[root@localhost .ssh]# echo "" >known_hosts
//清空此文件内容
创建存储:
进入存储:
通过远程连接软件上传ISO镜像文件至存储目录/var/lib/libvirt/images/
//前提是吧镜像下载到root下面
[root@localhost ~]# cd /var/lib/libvirt/images/
[root@localhost images]# ls
[root@localhost images]# mv /root/rhel-server-7.4-x86_64-dvd.iso .
[root@localhost 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
添加成功如下图所示