systemd管理进程的例子
vi /usr/lib/systemd/system/node_exporter.service
[Unit]
Description=node_exporter
[Service]
ExecStart=/usr/local/node_exporter/node_exporter
ExecReload=/bin/kill -HUP $MAINPID
KillMode=process
Restart=on-failure
[Install]
WantedBy=multi-user.target
systemctl daemon-reload
systemctl start node_exporter
systemctl enable node_exporter