Manage Puma with systemd on Ubuntu 16.04 and rvm

puma.service

[Unit]
Description=Puma Rails Server
After=network.target

[Service]
Type=simple
User=deploy
WorkingDirectory=/var/apps/upshift/current
ExecStart=/usr/local/rvm/bin/rbenv default do bundle exec pumactl -S /var/apps/upshift/shared/tmp/pids/puma.state -F /var/apps/upshift/shared/puma.rb start
ExecStop=/usr/local/rvm/bin/rbenv default do bundle exec pumactl -S /var/apps/upshift/shared/tmp/pids/puma.state -F /var/apps/upshift/shared/puma.rb stop
TimeoutSec=15
Restart=always

[Install]
WantedBy=multi-user.target

To get the values for ExecStart or ExecStop, run cap production puma:start or cap production puma:stop and copy the command that is printed to your console. For example, in this case it's the last line below:

$ cap production puma:start
00:00 puma:start
      01 /usr/local/rvm/bin/rvm default do bundle exec pumactl -S /var/apps/upshift/shared/tmp/pids/puma.state -F /var/apps/upshift/shared/puma.rb start`

Replace User, WorkingDirectory, ExecStart, and ExecStop above with values of your setup.