需求：

1、计算当前6379 、3306 服务的连接数
2、可prometheus 语法查询

下面代码可直接使用：
注：
1、windows 与linux的区分 第38行代码
localAddr := fields[1] //windows为fields[1] ， linux为fields[3]
2、如需求 增加/修改/删除 端口，可参考第70 71行即可

 70         NewPrometheusGauge(3306)71         NewPrometheusGauge(6379)

代码

package mainimport ("fmt""log""net/http""os/exec""strings""time""github.com/prometheus/client_golang/prometheus""github.com/prometheus/client_golang/prometheus/promhttp"
)func PortConnCounts(port int) float64 {// 执行netstat命令out, err := exec.Command("netstat", "-an").Output()if err != nil {fmt.Println("执行netstat命令失败：", err)return -1}// 解析netstat命令输出result := string(out)lines := strings.Split(result, "\n")// fmt.Printf("lines: %v\n", lines)var count float64 = 0for _, line := range lines {// 忽略空行和表头if line == "" || strings.Contains(line, "Active Internet connections") || strings.Contains(line, "Proto") {continue}fields := strings.Fields(line)if len(fields) >= 4 {// 获取本地地址和端口localAddr := fields[3] //windows为fields[1]  linux为fields[3]addrParts := strings.Split(localAddr, ":")if len(addrParts) >= 2 {localPort := addrParts[len(addrParts)-1]if localPort == fmt.Sprint(port) {count++}}}}log.Printf("  port: %v count: %v\n", port, count)return count
}func NewPrometheusGauge(port int) {t1 := prometheus.NewGauge(prometheus.GaugeOpts{Name: fmt.Sprint("portconnscount", port),Help: fmt.Sprint("portconnscount", port, "每10秒执行一次，端口链接数，误差1个左右， 误差在于:::ipv6的显示"),})// 注册指标prometheus.MustRegister(t1)// 每秒钟增加指标值go func() {for {t1.Set(PortConnCounts(port))time.Sleep(time.Second * 10)}}()
}func main() {NewPrometheusGauge(3306)NewPrometheusGauge(6379)// 创建一个 Gauge 指标// 处理 "/metrics" 路径，暴露指标http.Handle("/metrics", promhttp.Handler())log.Fatal(http.ListenAndServe(":9101", nil))
}

生成 二进制文件

//get 一下包
go get github.com/prometheus/client_golang/prometheus
go get github.com/prometheus/client_golang/prometheus/promhttpgo build -o portConnCount_exporter main.go

执行

nohup ./portConnCount_exporter &[root@www netstat.go]# tail -f nohup.out 
2023/08/09 15:56:39   port: 6379 count: 2272
2023/08/09 15:56:39   port: 3306 count: 100
2023/08/09 15:56:49   port: 3306 count: 100
2023/08/09 15:56:49   port: 6379 count: 2272
2023/08/09 15:56:59   port: 6379 count: 2272
2023/08/09 15:56:59   port: 3306 count: 100
2023/08/09 15:57:09   port: 6379 count: 2272
2023/08/09 15:57:09   port: 3306 count: 100
2023/08/09 15:57:20   port: 6379 count: 2272

网页访问
http://ip:9101/metrics

prometheus语法查询

Grafana

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