--restart option doesn't work on Ubuntu 16.04

[galcha]

The docker image doesn't load on system startup on Ubuntu 16.04 LTS with the command you provided :
$ docker run -d --name docker-hostmanager --restart=always -v /var/run/docker.sock:/var/run/docker.sock -v /etc/hosts:/hosts iamluc/docker-hostmanager

It worked flawlessly on Debian 8, though.
At the moment, I have to launch docker start docker-hostmanager manually.

[iamluc]

Unfortunately it is an ubuntu or docker bug and there is nothing we could do to fix that.

Maybe it is related to systemd and docker daemon started by socket activation