這篇主要整理作法步驟，此圖講解非常清楚

1. Raspberry pi 安裝 Nginx及擴充module
2. Raspberry pi nginx 增加模組 nginx-module-vts
3. Raspberry pi 安裝 Nginx_vts_exporter
4. Raspberry pi 安裝 Prometheus
5. Raspberry pi 安裝 Grafana

Reference

https://medium.com/@shevtsovav/ready-for-scraping-nginx-metrics-nginx-vts-exporter-prometheus-grafana-26c14816ae7c

https://grafana.com/blog/2019/08/22/homelab-security-with-ossec-loki-prometheus-and-grafana-on-a-raspberry-pi/

再往下新增Prometheus功能

# 下載 prometheus
$ wget https://github.com/prometheus/prometheus/releases/download/v2.14.0/prometheus-2.14.0.linux-armv7.tar.gz

# 解壓縮
$ tar -zxvf prometheus-2.14.0.linux-armv7.tar.gz

# 修改 prometheus.yml targets要改成Nginx-vts-exporter輸出網址
$ nano prometheus-2.14.0.linux-armv7/prometheus.yml

# static_configs:
#   - targets: ['localhost:9913']

# 新增系統服務
$ sudo nano /etc/systemd/system/prometheus.service
# 新增以下內容
[Unit]
Description=Prometheus Metrics
After=network.target

[Service]
Type=simple
User=pi
ExecStart=/home/pi/prometheus-2.14.0.linux-armv7/prometheus --storage.tsdb.retention.time=30d
WorkingDirectory=/home/pi/prometheus-2.14.0.linux-armv7/
Restart=always
RestartSec=10

[Install]
WantedBy=multi-user.target
 
#完成後，儲存離開
 
# 系統重新讀取服務
$ sudo systemctl daemon-reload
 
# 設定開機自動執行
$ sudo systemctl enable prometheus
 
# 啟動prometheus
$ sudo systemctl start prometheus
 
# 查詢執行狀況
$ sudo systemctl status prometheus

完成後即可以到http://localhost:9090，觀看prometheus運行狀況

http://localhost:9090/targets

Reference

https://grafana.com/blog/2019/08/22/homelab-security-with-ossec-loki-prometheus-and-grafana-on-a-raspberry-pi/

https://medium.com/@shevtsovav/ready-for-scraping-nginx-metrics-nginx-vts-exporter-prometheus-grafana-26c14816ae7c