Use targetcli in containers.
docker build -t targetcli -f Dockerfile .
./start-container.sh
docker exec -ti targetclid bash
# Create LUN disk with fileio
targetcli backstores/fileio create disk1 /disks/disk.img 1G
targetcli loopback/ create 50014051998a423d
targetcli loopback/naa.50014051998a423d/luns create /backstores/fileio/disk1