Automatic mounting of additional NBD volumes using systemd on Ubuntu

mount-nbd.sh

#!/bin/bash

if [ "$#" -ne 2 ] ; then
    echo 'Usage: mount-nbd.sh <device> <mount_point>'
    exit 1
fi
device=$1

fs_type=$(blkid -o value -s TYPE $device)
if [[ -z $fs_type ]] ; then
    echo "Formatting ${device}"
    mkfs -q -t ext4 $device
fi

fs_uuid=$(blkid -o value -s UUID $device)
if [[ -z $fs_uuid ]] ; then
    echo "Unable to find UUID"
    exit 1
fi
echo "Device ${device} UUID: ${fs_uuid}"

mnt_point=$2
if [[ -d $mnt_point ]] ; then
    if [  "$(ls -A $mnt_point)" ] ; then
        echo "Mount point is not empty!"
        exit 1
    fi
    echo "Warning: Mount point $mnt_point exists"
else
    mkdir -p $mnt_point
fi

if grep -q -e $device -e $mnt_point /etc/fstab ; then
    echo "/etc/fstab already contains mountpoint or device"
    exit 1
fi

service_name="$(sed s@^/@@g <<<$mnt_point)"
service_name="$(sed s@/@-@g <<<$service_name)"
service_name="${service_name}.mount"
service_path="/etc/systemd/system/${service_name}"
if [[ -f $service_path ]]; then
    echo "Service exists: ${service_path}"
    exit 1
fi

echo "Creating service: ${service_path}"

cat > $service_path <<EOL
[Unit]
Description=Mount NDB Volume at boot
After=network-online.target

[Mount]
What=UUID="$fs_uuid"
Where=$mnt_point
Type=ext4
Options=defaults

[Install]
WantedBy=multi-user.target
EOL

systemctl daemon-reload
echo "Starting service"
systemctl start $service_name
systemctl enable $service_name

Usage example:

root@server:~ ./mount-nbd.sh /dev/nbd1 /mnt/data
Formatting /dev/nbd1
Device /dev/nbd1 UUID: d42b7140-7f36-4674-a171-7e782f2dfa96
Creating service: /etc/systemd/system/mnt-data.mount
Starting service

root@server:~ df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/nbd0        46G  1.3G   43G   3% /
/dev/nbd1       138G   60M  131G   1% /mnt/data