qemush/bin/qemush

192 lines
4.3 KiB
Bash
Executable file

#!/usr/bin/env bash
# version=0.6.0
# Function to re-exec the script as another user via sudo (only if needed)
exec_as() {
local user
user="$1"
shift
if [ "$(whoami)" != "$user" ]; then
exec sudo -E -H -u "$user" -- "$0" "$@"
fi
}
# Exec the script as qemu
exec_as qemu "$@"
# Environment
PATH="${HOME}/launchers:${HOME}/bin:${PATH}"
EDITOR="${EDITOR:-nvim}"
export QEMUSH_NAME
# Aliases
ls='ls --color=auto'
# Set a restrictive umask to make sure qemu user files are private
umask 027
# Function to print a colored error
perror() {
>&2 printf '\033[1;31mKO:\033[0m \033[1m%s\033[0m\n' "$*"
}
# Function to show the usage
public_help() {
local name
name=$(basename "$0")
exec cat << EOF
${name}: usage:
${name} running - (default behaviour) list running VMs
${name} start <VM name> - start a VM
${name} attach <VM name> - attach to the VM monitor socket
${name} ls - list available VMs
${name} edit <VM name> - edit VM launching script
${name} rm <VM name> - delete launch script
${name} diskls - list available disk images
${name} diskadd <disk name> <size> - create a disk image
${name} diskrm <disk name> - delete disk image
${name} shell - start a shell as user qemu
${name} help - show this help
${name} add <path to script> [<VM name>] - add a launching script
${name} do <command> - run shell input as user qemu
EOF
}
# Function to throw an invalid usage error (skill issue)
error_usage() {
perror "Invalid usage"
>&2 public_help
return 1
}
# Function to start a virtual machine
public_start() {
QEMUSH_NAME="$1"
set -- "$@" \
-name "$QEMUSH_NAME" \
-monitor "unix:$(pathof socket),server,nowait" \
-daemonize
if ! "$@"; then
perror "error launching virtual machine \"${QEMUSH_NAME}\""
return 2
fi
}
# Attach to a running virtual machine output, the latest opened if no
# argument is provided
public_attach() {
QEMUSH_NAME="$1"
shift
exec socat -,rawer,escape=15 "UNIX-CONNECT:$(pathof socket)"
}
# List running virtual machines
public_running() {
cd || return
echo "Running machines:"
set -- $ls -t sockets/monitors "$@"
exec "$@"
}
# List available virtual machines entrypoints
public_ls() {
cd || return
echo "Available machines:"
set -- $ls launchers "$@"
exec "$@"
}
# Create a copy-on-write disk for a virtual machine
public_diskadd() {
QEMUSH_NAME="$1"
shift
exec qemu-img create -f qcow2 "$(pathof disk)" "$1"
}
# Delete a disk
public_diskrm() {
for disk in "$@"; do
QEMUSH_NAME="$disk"
rm -vi -- "$(pathof disk)"
done
}
# List available disks
public_diskls() {
cd || return
echo "Available disks:"
set -- $ls disks "$@"
exec "$@"
}
# Edit a virtual machine entrypoint with a text editor
public_edit() {
cd || return
local file="launchers/${1}"
"$EDITOR" "$file"
[ -f "$file" ] && exec chmod u+x "$file"
}
# Delete a virtual machine entrypoint
public_rm() {
cd ~/launchers || return
exec rm -vi -- "$@"
}
# Invoke bash as qemu user in its home directory
public_shell() {
cd || return
set -- bash -i "$@"
exec "$@"
}
# Output the content of an entrypoint, with coloration if on a virtual
# terminal
public_cat() {
cd ~/launchers || return
cat -- "$@"
}
# Copy a file in entrypoints folder
public_add() {
trap return EXIT
set -e
local name
if [ -n "$2" ]; then
name="$2"
else
name=$(basename "$1")
fi
name="${HOME}/launchers/${name}"
cp -vi -- "$1" "$name"
chmod 740 "$name"
set +e
trap - EXIT
}
# Run shell commands as qemu
public_do() {
exec sh -c "$*"
}
# Retrieve user requested function
function="$1"
shift
# Defauts to `active` if no function is supplied; else checks for a public
# function named after the argument; else fails
if [ -z "$function" ]; then
public_running
elif declare -F | cut -d \ -f 3- | grep '^public_' | sed 's/^public_//' | grep -q "^${function}$"; then
"public_${function}" "$@"
else
error_usage
fi