experiment2.bash

# Since we are simulating image layers through "backend" and "frontend" directories so mounting is
# being performed as read-only mode.

foo@bar:~$ mount -o ro backend-dev backend
mount -o ro frontend-dev frontend

# "fullstack" directory is simulating the container layer so it should be writable.
mount fullstack-dev fullstack

# Create workdir
mkdir -f fullstack/upper fullstack/workdir

# perform union mount using overlayfs.
mount -t overlay -o \
lowerdir=frontend:backend,\
upperdir=fullstack/upper,\
workdir=fullstack/workdir \
none union

ls union
git  java  javascript  lost+found