buildroot/package/nginx/nginx.service

[Unit]
Description=A high performance web server and a reverse proxy server
After=syslog.target network.target

[Service]
Type=forking
PIDFile=/var/run/nginx.pid
ExecStartPre=/usr/bin/mkdir -p /var/log/nginx /var/tmp/nginx
ExecStartPre=/usr/sbin/nginx -t -q -g 'pid /var/run/nginx.pid; daemon on; master_process on;'
ExecStart=/usr/sbin/nginx -g 'pid /var/run/nginx.pid; daemon on; master_process on;'
ExecReload=/usr/sbin/nginx -g 'pid /var/run/nginx.pid; daemon on; master_process on;' -s reload
ExecStop=/usr/sbin/nginx -g 'pid /var/run/nginx.pid;' -s quit
PrivateDevices=yes

[Install]
WantedBy=multi-user.target