In order to start your minions during boot-time you have two options.
If your minions are running on a system that supports systemd, you could use the provided systemd unit file for Gru.
Or you could use supervisord for process control.
Get the systemd unit file from the contrib/systemd directory and install it on your system.
Check Unit File Load Path document for the location where you should install your unit file.
Once you've got the unit in place, execute these commands which will enable and start your minion.
$ sudo systemctl daemon-reload
$ sudo systemctl enable gru-minion
$ sudo systemctl start gru-minion
Get the supervisord config file from contrib/supervisord
directory and place in under your supervisord include
directory.
Once you've got the file in place, reload the supervisord configuration, enable and start the service.
$ sudo supervisorctl reread
$ sudo supervisorctl reload
$ sudo supervisorctl start gru-minion