Simple init script to manage KVM virtual machines.
kvm-simple-init can perform the following actions on a KVM machine :
-
Start
-
Stop by sending a system power down event to the guest system
-
Kill by stopping immediatly the QEMU emulator (automatic fallback on this action if the VM does not respond to stop action)
-
Restart
kvm-simple-init focuses on simplicity, and is fully implemented in just a few hundred lines of shell script.
It is intended for people who do not want to run libvirt just for running a few VM, or people who prefer to manage flat configuration files using their prefered configuration management system.
kvm-simple-init does not provide complicated configuration file format or parameters. Only two informations are needed :
-
QEMU monitor port for the machine (used to know if the VM is running, or to send specific commands)
-
Full KVM command line needed to start the machine (gives full configuration freedom)
kvm-simple-init can be used directly as system init script for starting all KVM
machines on a host machine. Just drop it in /etc/init.d, and enable it with
the tools provided by your UNIX distribution (update-rc.d on Debian,
chkconfig on Red Hat, ...).
kvm-simple-init was inspired by the init script of FreeBSD jails.
You need to have the following tools :
- Posix shell (
/bin/sh) - Netcat (available via the
nccommand) timeoutcommand (part of coreutils in Debian)- Of course a working QEMU/KVM setup, available via the
kvmcommand
Then, drop kvm-simple-init somewhere into your PATH (/usr/local/sbin could
be a good place), or into /etc/init.d if intended to be used as system init
script.
Currently, this tool has only been tested on Debian 6.0 and 7.0.
Here is the command synopsis, also found when running kvm-simple-init with no arguments :
kvm-simple-init [start|stop|restart] [VM]
The directory /etc/kvm-simple-init/ contains the VMs configuration files.
The specified action (start, stop or restart) is executed :
- If VM argument is specified, using the matching file in the directory
- If not, using all files in the directory
VM configuration files should contain at least two shell variables :
MONITOR_PORT: Unique port number which need to be also specified in the-monitorKVM parameter (using theKVM_OPTSvariable below)KVM_OPTS: KVM arguments necessary to launch the VM
Warning : if the virtual machine does not respond to stop action (because the operating system does not manage it, or is in a bad state), the machine will be violently interrupted.
Create /etc/kvm-simple-init/test1 :
# Should be unique among all VMs
MONITOR_PORT=5805
# Not mandatory, but useful to keep it in a distinct variable
VNC_DISPLAY=5
# KVM parameters
KVM_OPTS="\
-cpu host -m 1024 -smp 1 \
-drive index=0,media=disk,file=/srv/kvm/test1.raw,if=virtio \
-vnc 127.0.0.1:$VNC_DISPLAY -monitor tcp:127.0.0.1:$MONITOR_PORT,server,nowait \
-daemonize \
"
Then, manage the VM with :
/etc/init.d/kvm-simple-init start test1
/etc/init.d/kvm-simple-init stop test1
/etc/init.d/kvm-simple-init restart test1
To manage all the VMs (usually when booting or stopping the system) :
/etc/init.d/kvm-simple-init start
/etc/init.d/kvm-simple-init stop
/etc/init.d/kvm-simple-init restart
- 2013-05-30 : Package for Debian
- 2013-05-30 : Add man page
- 2013-05-30 : Add status command (also for LSB compliance)
- 2013-06-03 : Add parameter AUTOSTART to VM config
Copyright 2013 Thomas Martin thomas@oopss.org
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.