Creating a Monitoring Agent in Go


Building a monitoring agent involves collecting metrics from a system and sending them to a monitoring server or displaying them on a dashboard.

Step-by-Step Guide

Define Metrics Structure:

Create a structure to store metrics.

type Metric struct {
    Name  string
    Value float64
}

Collect Metrics:

Implement functions to collect various system metrics (CPU usage, memory usage, etc.).

import (
    "github.com/shirou/gopsutil/cpu"
    "github.com/shirou/gopsutil/mem"
)

func collectCPUMetrics() Metric {
    usage, _ := cpu.Percent(0, false)
    return Metric{Name: "cpu_usage", Value: usage[0]}
}

func collectMemoryMetrics() Metric {
    v, _ := mem.VirtualMemory()
    return Metric{Name: "memory_usage", Value: v.UsedPercent}
}

Send Metrics:

Implement a function to send metrics to a monitoring server (e.g., Prometheus, InfluxDB).

import (
    "bytes"
    "encoding/json"
    "net/http"
)

func sendMetrics(metrics []Metric, url string) error {
    jsonData, err := json.Marshal(metrics)
    if err != nil {
        return err
    }

    resp, err := http.Post(url, "application/json", bytes.NewBuffer(jsonData))
    if err != nil {
        return err
    }
    defer resp.Body.Close()

    return nil
}

Main Function:

Collect and send metrics in the main function.

func main() {
    metrics := []Metric{
        collectCPUMetrics(),
        collectMemoryMetrics(),
    }

    err := sendMetrics(metrics, "http://monitoring-server/metrics")
    if err != nil {
        log.Fatal(err)
    }

    log.Println("Metrics sent successfully")
}