Script to launch QEMU in user mode

web01.sh

#!/usr/bin/env bash
#
# See: https://drewdevault.com/2018/09/10/Getting-started-with-qemu.html
# See: https://wiki.archlinux.org/index.php/QEMU
#
# Host preparation (as root):
#
# ip link add br0 type bridge
# ip addr add 172.20.0.1/16 dev br0
# ip link set br0 up
# ip tuntap add dev tap0 mode tap user aorth
# ip link set tap0 up promisc on
# brctl addif br0 tap0
#

NAME=web01
ISO=/home/aorth/Downloads/ubuntu-18.04.1-live-server-amd64.iso
HD1=/home/aorth/src/web01.qcow2
# See: https://blogs.igalia.com/berto/2015/12/17/improving-disk-io-performance-in-qemu-2-5-with-the-qcow2-l2-cache/
HD1_L2CACHE_SIZE=2621440
MEM=4096
TAP_DEVICE=tap0
SPICE_PORT=5930

function install() {

    qemu-system-x86_64 \
        -daemonize \
        -enable-kvm \
        -cpu host \
        -m ${MEM} \
        -nic user,model=virtio \
        -nic tap,ifname=${TAP_DEVICE},script=no,downscript=no,model=virtio \
        -drive file=${HD1},l2-cache-size=${HD1_L2CACHE_SIZE},media=disk,if=virtio \
        -cdrom ${ISO} \
        -boot order=d \
        -vga qxl \
        -spice port=${SPICE_PORT},disable-ticketing

}

function run() {

    qemu-system-x86_64 \
        -daemonize \
        -enable-kvm \
        -cpu host \
        -m ${MEM} \
        -nic user,model=virtio \
        -nic tap,ifname=${TAP_DEVICE},script=no,downscript=no,model=virtio \
        -drive file=${HD1},l2-cache-size=${HD1_L2CACHE_SIZE},media=disk,if=virtio \
        -boot order=c \
        -vga qxl \
        -spice port=${SPICE_PORT},disable-ticketing
}

# install if -i is passed, otherwise just run
if [[ $# -eq 1 && $1 == "-i" ]]; then
    echo -n "Installing ${NAME}..."

    install
else
    echo -n "Running ${NAME}..."

    run
fi

echo " connect via SPICE:"
echo
echo -e "\tspicy -h 127.0.0.1 -p ${SPICE_PORT}"

exit 0