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:
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
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
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