May 2019

Create a systemd drop-in directory for the docker service

$ sudo mkdir -p /etc/systemd/system/docker.service.d

Solution 1: losetup

With newer version of losetup, you can easy map parition in image file to /dev/loop*.

sudo losetup --show -Pf <imagefile>
# /dev/loop0

sudo partprobe /dev/loop0

The output will show which loop device has been mapped to image file. Now you can mount partition of it.
Example:

sudo mount /dev/loop0p1 /mnt