odoo-docker/system/database.service

[Unit]
Description=PostgreSQL 9.4 service container
Requires=docker.service network-online.target
After=docker.service network-online.target

[Service]
Restart=always
ExecStart=/usr/bin/docker start -a database
ExecStop=/usr/bin/docker stop -t 2 database

[Install]
WantedBy=multi-user.target