git clone https://github.com/docker-32bit/ubuntu.git
At the end, you will see docker ubuntu image in docker images command
Example
root@ubuntu:~# docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
32bit/ubuntu 16.04 f0d5da5c8c89 About an hour ago 319.7 MB
32bit/ubuntu 14.04 6de534a1b6e3 21 months ago 290.7 MB
docker run -dt --name <name> <ubuntuimage:>
Example
root@ubuntu:~# docker run -dt --name ubuntu32 32bit/ubuntu:16.04 bash
82565735aec437ee465b8a4b423b87b520749e97e406e52cda21631d7faf6232
root@ubuntu:~# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
82565735aec4 32bit/ubuntu:16.04 "bash" 3 seconds ago Up 2 seconds ubuntu32
3af893a959a9 32bit/ubuntu:16.04 "bash" 41 minutes ago Up 41 minutes u32
https://github.com/docker/docker/issues/7924
https://github.com/docker-32bit/ubuntu