pm2 startup upstart
sudo env PATH=$PATH:/usr/bin /usr/lib/node_modules/pm2/bin/pm2 startup upstart -u vagrant --hp /home/vagrant
/etc/systemd/system/node_api
[Unit]
Description=API
After=network.target
[Service]
User=username
Environment=HOST=localhost
WorkingDirectory=/app
ExecStart=/usr/bin/node index.js
[Install]
WantedBy=multi-user.target