Shemum/shemum

#!/usr/bin/env sh
#
# Author: Adrian Erik Hoemann
# Date: 9.18.2024

# TODO: Implement operating system installer variable list.

# Debug mode
# Default: true
DEBUG=true

# Debug mode check 
if [$DEBUG -eq true]
  set +x
fi

# Arguments
OPTION=$1
OS_NAME=$2

# Defining paths
ROOT_PATH="$HOME/Machines"
ISO_PATH="$ROOT_PATH/$OS_NAME/$OS_NAME.iso"
IMG_PATH="$ROOT_PATH/$OS_NAME/$OS_NAME.img"

# Sources default values
. ".env"

# Sources virtual machine specific values
. "$ROOT_PATH/$OS_NAME/.env"

# Functions

# Defines install image source
def_os_source() {
  case $OS_NAME in
    "openbsd")
      INSTALL_IMG="https://cdn.openbsd.org/pub/OpenBSD/7.5/i386/cd75.iso"
    ;;
    "debian")
      INSTALL_IMG=""
    ;;
    *)
      err_func "INSTALL_IMG for $OS_NAME not found"
    ;;
  esac
}

check_func() {
  if [ -z $OS_NAME ]
    err_func "Operating system is empty"
  fi
  if [ -z $INSTALL_IMG ]
    info_func "$INSTALL_IMG is not set"
  fi

}

err_func() {
  printf "$@" >&2
  exit 1
}

warn_func() {
  printf "$@" >&2
}

info_func() {
  printf "$@" >&1
}

# Virtual machine removal
remove_func() {
  rm -r $ROOT_PATH/$OS_NAME 
}

# Virtual machine start without a console
start_func() {
  qemu-system-x86_64 -boot c                            \
                       -display none                    \
                       -drive file=$IMG_PATH,format=raw \
                       -m $RAM -smp $CPU
}

# Virtual machine start with a console
console_func() {
  qemu-system-x86_64 -boot c                    \
                       -display curses            \
                       -drive file=$IMG_PATH,format=raw \
                       -m $RAM -smp $CPU
}

# Virtual machine initialization with a console
init_func() {
  def_os_source
  mkdir -p "$ROOT_PATH/$OS_NAME"
  qemu-img create $IMG_PATH $DISK_SIZE
  if [ ! -f $ISO_PATH ] && [ ! -z $INSTALL_IMG ]; then
    info_func "Fetching $OSNAME installer at: $INSTALL_IMG"
    curl -o $ISO_PATH $INSTALL_IMG
  elif [ ! -z $INSTALL_IMG ]; then
    info_func "Current INSTALL_IMG for $OS_NAME: $ISO_PATH"
  else
    err_func "Install image path is missing"
  fi
  qemu-system-x86_64 -boot d                          \
                    -display curses                   \
                    -drive file=$ISO_PATH,media=cdrom \
                    -drive file=$IMG_PATH,format=raw  \
                    -m $RAM -smp $CPU
}

# Display usage
usage_func() {
  printf "Usage: shemum [init] <virtual machine name> <disk size>"
  printf " init        initialize a virtual machine"
  printf " start       start a QEMU virtual machine without console output"
  printf " console     start a QEMU virtual machine with console output"
  printf " remove      remove virtual machine directory and all it's contents"
}

# Options
case $OPTION in
  "init")
    init_func
  ;;
  "console")
    console_func
  ;;
  "start")
    start_func
  ;;
  "remove")
    remove_func
  ;;
  *)
    usage_func
esac