Spin an Ubuntu VM from a cloud image

spin-vm.sh

#!/bin/bash

# quick and dirty script to spin a ubuntu VM based on a cloud image

NAME=''
DISK_SIZE=''
RAM='1024'
CPU='1'
LOCATION='TBD' 
QEMU_IMG='/usr/bin/qemu-img'
VIRT_INSTALL='/usr/bin/virt-install'
BACKING_IMAGE='TBD' # path to the original ubuntu cloud image
SEED='TBD' # path to the seed cd image created with cloud-localds

usage() {
  echo "$1" >&2
  echo "usage: $0 NAME DISK_SIZE [RAM] [CPU] [LOCATION]" >&2
  exit 1
}

if [[ $# -lt 2 || $# -gt 5 ]]; then
  usage "Bad number of arguments!"
fi

NAME="$1"
DISK_SIZE="$2"

if [[ $# -gt 2 ]]; then
  RAM="$3"
fi

if [[ $# -gt 3 ]]; then
  CPU="$4"
fi

if [[ $# -gt 4 ]]; then
  LOCATION="$5"
fi

if [[ ! -x "$QEMU_IMG" ]]; then
  usage "$QEMU_IMG not found!"
fi

if [[ ! -x "$VIRT_INSTALL" ]]; then
  usage "$VIRT_INSTALL not found!"
fi

if [[ ! -f "$BACKING_IMAGE" ]]; then
  usage "$BACKING_IMAGE not found!"
fi

if [[ ! -f "$SEED" ]]; then
  usage "$SEED not found!"
fi

DISK="${LOCATION}/${NAME}.qcow2"
sudo $QEMU_IMG create -f qcow2 -b "$BACKING_IMAGE" "$DISK" "$DISK_SIZE"

if [[ $? -ne 0 ]]; then
  echo "Failed to create $DISK" >&2
  rm -f "$DISK" 2>/dev/null
  exit 1
fi

sudo chown libvirt-qemu:kvm "$DISK"

$VIRT_INSTALL --connect "qemu:///system" \
  -n "$NAME" \
  -r "$RAM" \
  --os-type "linux" \
  --os-variant "ubuntu16.04" \
  --disk "$DISK,bus=virtio" \
  --network network="default" \
  --graphics none \
  --cdrom "$SEED"

if [[ $? -ne 0 ]]; then
  rm -f "$DISK" 2>/dev/null
  exit 1
fi