使用 libvirt 快速创建 CentOS Stream 8 虚拟机

目标：快速创建一个 CentOS Stream 8 虚拟机，用于开发和测试。

1. 获取 CentOS Stream 8 虚拟机磁盘镜像（qcow2）

   URL="https://cloud.centos.org/centos/8-stream/x86_64/images/$(curl -SsLf https://cloud.centos.org/centos/8-stream/x86_64/images/ | grep -Po '(?<=href=")CentOS-Stream-GenericCloud-8[^"]+.qcow2(?=")' | tail -1)"
   
   curl -Lo /var/lib/libvirt/images/centos-stream-8.qcow2 "${URL}"
   

2. 修改虚拟机 root 密码为 12345

   docker run -it --rm \
     -v /var/lib/libvirt/images:/data \
     -w /data \
     -u "$(id -u):$(id -g)" \
     --entrypoint /usr/bin/env \
     bkahlert/libguestfs \
     -- virt-customize -a centos-stream-8.qcow2 --root-password password:12345 --uninstall cloud-init
   

3. 修改虚拟机磁盘大小为 64G

   docker run -it --rm \
     -v /var/lib/libvirt/images:/data \
     -w /data \
     -u "$(id -u):$(id -g)" \
     --entrypoint /usr/bin/env \
     bkahlert/libguestfs \
     -- qemu-img resize centos-stream-8.qcow2 64G
   

4. 创建虚拟机（4核8G，默认NAT网络）

   virt-install \
     --name centos-stream-8 \
     --os-type=Linux \
     --vcpus 4 \
     --memory 8192 \
     --disk /var/lib/libvirt/images/centos-stream-8.qcow2,bus=virtio --import \
     --network network=default,model=virtio \
     --graphics none \
     --noautoconsole
   

5. SSH 登入虚拟机

   # 获取虚拟机 IP
   virsh domifaddr centos-stream-8
   # Name       MAC address          Protocol     Address
   # -------------------------------------------------------------------------------
   # vnet0      52:54:00:6c:41:39    ipv4         192.168.122.46/24
   
   IP=$(virsh domifaddr centos-stream-8 | grep -Po '\d+\.\d+\.\d+\.\d+')
   ssh "root@${IP}"
   # 密码为前面设置的 12345
   

6. 【虚拟机内】拓展分区大小为磁盘大小

   # 拓展分区大小
   growpart /dev/vda 1
   xfs_growfs /
   
   # 确认分区大小
   df -Th
   

7. 【虚拟机内】设置静态 IP 地址 & DNS

   sed -Ei -e '/^BOOTPROTO=.*$/d' -e '/^PERSISTENT_DHCLIENT=.*$/d' /etc/sysconfig/network-scripts/ifcfg-eth0
   
   cat >>/etc/sysconfig/network-scripts/ifcfg-eth0 <<EOF
   $(ip route | sed -En \
     -e 's|^[^/]+/([^ ]+) dev eth0 .* src ([^ ]+) .*$|PREFIX="\1"\nIPADDR="\2"|p' \
     -e 's|^default via ([^ ]+) dev eth0 .*$|GATEWAY="\1"|p')
   DNS1="223.5.5.5"
   DNS2="223.6.6.6"
   EOF
   
   # 确认配置无误
   cat /etc/sysconfig/network-scripts/ifcfg-eth0
   
   # 可选：设置 hostname 为 IP 地址
   hostnamectl set-hostname "$(hostname -I | sed 's|\.|-|g')"
   

8. 转发虚拟机 SSH 服务端口到本地端口 22XXX

   # IP=$(virsh domifaddr centos-stream-8 | grep -Po '\d+\.\d+\.\d+\.\d+')
   LOCAL_PORT=22$(grep -Po '\d+$' <<< "${IP}" | xargs printf '%03d')
   
   docker run -d --name="ssh-${LOCAL_PORT}" --restart=always --net=host alpine/socat \
       tcp-listen:"${LOCAL_PORT}",fork,reuseaddr tcp4-connect:"${IP}":22