feat: implement cross-platform metric collector with gopsutil, rename module to nexusrmm.local/agent

Agent/internal/collector/collector.go

@@ -0,0 +1,100 @@
+package collector
+
+import (
+	"time"
+
+	"github.com/shirou/gopsutil/v3/cpu"
+	"github.com/shirou/gopsutil/v3/disk"
+	"github.com/shirou/gopsutil/v3/host"
+	"github.com/shirou/gopsutil/v3/mem"
+	psnet "github.com/shirou/gopsutil/v3/net"
+)
+
+type Metrics struct {
+	CPUPercent      float64
+	MemoryPercent   float64
+	MemoryTotal     uint64
+	MemoryAvailable uint64
+	Disks           []DiskInfo
+	Networks        []NetInfo
+	UptimeSeconds   float64
+}
+
+type DiskInfo struct {
+	MountPoint string
+	Total      uint64
+	Free       uint64
+	Filesystem string
+}
+
+type NetInfo struct {
+	Name      string
+	IPAddress string
+	MAC       string
+	BytesSent uint64
+	BytesRecv uint64
+}
+
+func Collect() (*Metrics, error) {
+	cpuPercent, err := cpu.Percent(time.Second, false)
+	if err != nil {
+		return nil, err
+	}
+
+	memInfo, err := mem.VirtualMemory()
+	if err != nil {
+		return nil, err
+	}
+
+	uptime, _ := host.Uptime()
+
+	m := &Metrics{
+		CPUPercent:      cpuPercent[0],
+		MemoryPercent:   memInfo.UsedPercent,
+		MemoryTotal:     memInfo.Total,
+		MemoryAvailable: memInfo.Available,
+		UptimeSeconds:   float64(uptime),
+	}
+
+	// Disks
+	partitions, _ := disk.Partitions(false)
+	for _, p := range partitions {
+		usage, err := disk.Usage(p.Mountpoint)
+		if err != nil {
+			continue
+		}
+		m.Disks = append(m.Disks, DiskInfo{
+			MountPoint: p.Mountpoint,
+			Total:      usage.Total,
+			Free:       usage.Free,
+			Filesystem: p.Fstype,
+		})
+	}
+
+	// Network
+	interfaces, _ := psnet.Interfaces()
+	counters, _ := psnet.IOCounters(true)
+	counterMap := make(map[string]psnet.IOCountersStat)
+	for _, c := range counters {
+		counterMap[c.Name] = c
+	}
+	for _, iface := range interfaces {
+		if len(iface.Addrs) == 0 {
+			continue
+		}
+		ni := NetInfo{
+			Name: iface.Name,
+			MAC:  iface.HardwareAddr,
+		}
+		if len(iface.Addrs) > 0 {
+			ni.IPAddress = iface.Addrs[0].Addr
+		}
+		if c, ok := counterMap[iface.Name]; ok {
+			ni.BytesSent = c.BytesSent
+			ni.BytesRecv = c.BytesRecv
+		}
+		m.Networks = append(m.Networks, ni)
+	}
+
+	return m, nil
+}