Create image file, format it and then mount it

mk_mnt_img.sh

#!/bin/bash

# Untested shell script to create and mount an image file. Pretty much a copy/paste
# from this site:
#
# http://ubuntuhak.blogspot.com/2012/10/how-to-create-format-and-mount-img-files.html

img_file="/tmp/bucket.img"
img_size_in_mb="1024"
mount_point="/tmp/bucket"

# Create 1 GB "bucket"
sudo dd if=/dev/zero of=${img_file} bs=1M count=${img_size_in_mb}

# Format new image file
sudo mkfs ext4 -m0 -F ${img_file}

sudo mkdir -p ${mount_point}
sudo mount -o loop,rw,sync ${img_file} ${mount_point}

Thanks!