VMTools

This project contains some simple bash-based VM management tools for a libvirt hypervisor. It is opinionated regarding the infrastructure.

Assumptions

• Hypervisor is controlled by libvirt
• Host disks are stored in a storage pool
• Cloud images are stored in a storage pool (might be the same as the disk pool)
• VMs can be configured using cloud-init

Features

• list all available images (vm images)
• start a new VM using a cloud image and configure it according to a template (vm create)
• destroy a VM and optionally its associated storages (vm destroy)
• update image disks according to image specification (vm updateimage)

What you need

• a hypervisor with libvirtd
• libvirt's virsh on the machine running the scripts (might be a remote host or the hypervisor itself)
• QEMU installed if you want to upload qcow images

Installation

Installation is done by running make install:

# install to /usr/local
sudo make install

# install to "$HOME/vmtools" (don't forget to add $HOME/vmtools/bin to your path)
make prefix="$HOME/vmtools" install

Configuration

VMTools can be configured by editing ~/.vmtools/config.

Configuration options and default values

# storage pool for disks
POOL=default

# storage pool for images
IMAGEPOOL=images

# default memory size for new vms
MEMSIZE=512M

# default size for disk0 for resizing (disks are not resized by default, example: 20G)
DISKSIZE[0]=

# default number of virtual cpus
VCPUS=1

# default image (example: ubuntu-14.04)
IMAGE=

# remove storage when destroying a vm (y or n)
REMOVESTORAGE=n

# attach to console after vm creation
ATTACH=n

# dns domain of vms. if you specify this, vmdestroy will also delete the hostkey from ~/.ssh/known_hosts
DOMAIN=

# ssh public key for login (multiple keys can be added by using SSHKEY[0]="..." SSHKEY[1]="..." and so on) 
SSHKEY=

Usage

Management of the hypervisor is done using virsh from libvirt. This means the scripts can be run on the hypervisor itself or on a remote host. LIBVIRT_DEFAULT_URI must be set accordingly.

List available images (vm images)

All available images can be listed by running

vm images

Update images (vm updateimage)

# (re)download disks for ubuntu-16.04 image
vm updateimage ubuntu-16.04

Starting a VM (vm create)

A new Ubuntu 16.04 vm with 2 GB memory can be started by invoking:

vm create myvm --image=ubuntu-16.04 --memory=2G

You can specify a different memory size (--memory=), resize the disks during provisioning (--disk0-size=) or change the number of virtual cpus (--vcpus=). To see all arguments, invoke vmcreate --help.

Memory and disk size can be specified using raw values or with a unit:

• 1b = 1 byte
• 1k = 1.000 bytes
• 1m = 1.000.000 bytes
• 1g = 1.000.000.000 bytes
• 1K = 1.024 bytes
• 1M = 1.048.576 bytes (1.024 ^ 2)
• 1G = 1.073.741.824 bytes (1.024 ^ 3)

Destroying a VM (vm destroy)

A running vm can be destroyed using:

vm destroy myvm

For a full list of features see vm destroy --help

Notes

• Tested on Ubuntu 16.04.2 LTS host