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Libvirt

Tips​

  • libvirt/libvirt
    • 绑定: c#, go, java, ocaml. perl, python, php, ruby
    • API 分为: common, domain, domain snapshot, error, event, host, interface, network, node device, network filter, secret, storage, stream
  • libvirt
    • LXC – Linux Container - 容器
    • OpenVZ – lightweight Linux container system
    • Kernel-based Virtual Machine/QEMU (KVM) – open source hypervisor for Linux and SmartOS
    • Xen – Bare-Metal hypervisor
    • User-mode Linux (UML) paravirtualized kernel
    • VirtualBox – hypervisor by Oracle (formerly Sun) for Windows, Linux, Mac OS X, and Solaris
    • VMware ESX and GSX – hypervisors for Intel hardware
    • VMware Workstation and Player – hypervisors for Windows and Linux
    • Hyper-V – hypervisor for Windows by Microsoft
    • PowerVM – hypervisor by IBM for AIX, Linux and IBM i
    • Parallels Workstation – hypervisor for Mac by Parallels IP Holdings GmbH
    • Bhyve – hypervisor for FreeBSD 10+.
  • QEMUSwitchToLibvirt
  • UbuntuKVMWalkthrough
  • libvirt cloud-init with static networking
  • 概念 - API
    • domain
      • Guest Host
    • network
    • storage pool
    • storage volume
  • 问题
  • libvirt-client
# macOS
# 安装 vbox
brew install libvirt

# alpine
apk add virt-install

# 检测宿主机支持情况
virt-host-validate

# 启动服务进程
libvirtd -v

# 客户端连接
# https://libvirt.org/uri.html
# https://libvirt.org/remote.html
virsh -c vbox:///session
# 日志控制
LIBVIRT_LOG_FILTERS=1:vbox virsh -c vbox:///session
# export LIBVIRT_DEFAULT_URI="qemu+ssh://root@192.168.1.100/system"
virsh -c 'qemu+ssh://root@192.168.1.2/system'

# 问题排查
# user 会使用 /usr/local/var/run/libvirt/libvirt-sock
LIBVIRT_LOG_FILTERS=1:* virsh -c 'qemu+ssh://admin@192.168.1.2/system' list
# 修改使用的 socket
virsh -c 'qemu+ssh://admin@192.168.1.2/system?socket=/var/run/libvirt/libvirt-sock' list

# user 会使用 /usr/local/var/run/libvirt/libvirt-sock
virsh -c 'unix+ssh://admin@192.168.1.2/run/libvirt/libvirt-sock' list
# 如果是非 root，先验证能访问
virsh -c unix:///run/libvirt/libvirt-sock list
# 可以转发 unix socket
ssh -R /run/libvirt/libvirt-sock:127.0.0.1:16509 admin@192.168.1.2 -Nv

export VIRSH_DEFAULT_CONNECT_URI=qemu:///system
virsh list --all

# 虚拟机列表
virsh list

# https://wiki.libvirt.org/page/SSHSetup
echo 'unix_sock_group = "libvirt"' >> /etc/libvirt/libvirtd.conf
echo 'unix_sock_rw_perms = "0770"' >> /etc/libvirt/libvirtd.conf
usermod -G libvirt -a $USER
rc-service libvirtd restart

virsh -c qemu+ssh://username@hostname/system

驱动​

https://pkgs.alpinelinux.org/contents?file=&path=%2Fusr%2Flib%2Flibvirt%2Fconnection-driver&name=&branch=edge&arch=x86_64

invalid argument: Failed to parse user 'qemu'​

XML​

virt-xml-validate /path/to/XML/file

virt-install​

virt-install --virt-type kvm --name xp \
  --location http://httpredir.debian.org/debian/dists/squeeze/main/installer-amd64/ \
  --extra-args "console=ttyS0" -v --os-variant debiansqueeze \
  --disk size=4 --memory 512
-n xp --vcpus 2 --import winxp

virt-install
--connect qemu:///system
--virt-type qemu
--name demo
--ram 500
--graphics vnc
--disk path=/root/alp.qcow2
--cdrom /root/alpine-standard-3.8.0-x86_64.iso
--os-variant=generic
--dry-run --print-xml

https://wiki.debian.org/KVM

Usage:
  libvirtd [options]

Options:
  -h | --help            Display program help:
  -v | --verbose         Verbose messages.
  -d | --daemon          Run as a daemon & write PID file.
  -l | --listen          Listen for TCP/IP connections.
  -t | --timeout <secs>  Exit after timeout period.
  -f | --config <file>   Configuration file.
  -V | --version         Display version information.
  -p | --pid-file <file> Change name of PID file.

libvirt management daemon:

  Default paths:

    Configuration file (unless overridden by -f):
      $XDG_CONFIG_HOME/libvirt/libvirtd.conf

    Sockets:
      $XDG_RUNTIME_DIR/libvirt/libvirt-sock

    TLS:
      CA certificate:     $HOME/.pki/libvirt/cacert.pem
      Server certificate: $HOME/.pki/libvirt/servercert.pem
      Server private key: $HOME/.pki/libvirt/serverkey.pem

    PID file:
      $XDG_RUNTIME_DIR/libvirt/libvirtd.pid

virsh -c qemu+ssh://root@127.0.0.1:2222/system?socket=/var/run/libvirt/libvirt-sock list --all

http://rabexc.org/posts/how-to-get-started-with-libvirt-on

https://libvirt.org/formatdomain.html

listen_tls = 0
listen_tcp=1
auth_tcp="none"


unix_sock_dir = "/usr/local/var/run/libvirt"
unix_sock_ro_perms = "0777"
unix_sock_rw_perms = "0770"

auth_unix_ro = "none"
auth_unix_rw = "none"