WSL: Automatically mount disk on WSL startup

mount-disk.service

[Unit]
Description = Mount disk
Before = local-fs-pre.target

[Service]
User = root
Type = oneshot
RemainAfterExit = yes
ExecStart = /usr/local/sbin/mount-disk.sh

[Install]
WantedBy=default.target

mount-disk.sh

#!/bin/bash
set -eo pipefail

if [[ "$EUID" -ne 0 ]]; then
    echo "Script should run as root"
    exit 1
fi

DISK='/dev/disk/by-id/<disk-id>'

# Needs a Windows Task for mounting the disk to WSL
# See: https://github.com/microsoft/WSL/issues/6073#issuecomment-1266405095
/mnt/c/Windows/system32/schtasks.exe /run /tn mount-wsl-disk

# schtasks returns immediately, the disk might not be mounted 
# before we want to run the mount command
while [[ ! -b "$DISK" ]]; do
    echo -n .
    sleep 1
done

mount "$DISK-part1" /backup