add per-interface and cumulative network traffic charts (#926)

Co-authored-by: Sven van Ginkel <svenvanginkel@icloud.com>

agent/network.go

@@ -1,13 +1,83 @@
 package agent
 
 import (
+	"fmt"
 	"log/slog"
 	"strings"
 	"time"
 
+	"github.com/henrygd/beszel/internal/entities/system"
 	psutilNet "github.com/shirou/gopsutil/v4/net"
 )
 
+func (a *Agent) updateNetworkStats(systemStats *system.Stats) {
+	// network stats
+	if len(a.netInterfaces) == 0 {
+		// if no network interfaces, initialize again
+		// this is a fix if agent started before network is online (#466)
+		// maybe refactor this in the future to not cache interface names at all so we
+		// don't miss an interface that's been added after agent started in any circumstance
+		a.initializeNetIoStats()
+	}
+
+	if systemStats.NetworkInterfaces == nil {
+		systemStats.NetworkInterfaces = make(map[string][4]uint64, 0)
+	}
+
+	if netIO, err := psutilNet.IOCounters(true); err == nil {
+		msElapsed := uint64(time.Since(a.netIoStats.Time).Milliseconds())
+		a.netIoStats.Time = time.Now()
+		totalBytesSent := uint64(0)
+		totalBytesRecv := uint64(0)
+		netInterfaceDeltaTracker.Cycle()
+		// sum all bytes sent and received
+		for _, v := range netIO {
+			// skip if not in valid network interfaces list
+			if _, exists := a.netInterfaces[v.Name]; !exists {
+				continue
+			}
+			totalBytesSent += v.BytesSent
+			totalBytesRecv += v.BytesRecv
+
+			// track deltas for each network interface
+			netInterfaceDeltaTracker.Set(fmt.Sprintf("%sdown", v.Name), v.BytesRecv)
+			netInterfaceDeltaTracker.Set(fmt.Sprintf("%sup", v.Name), v.BytesSent)
+			upDelta := netInterfaceDeltaTracker.Delta(fmt.Sprintf("%sup", v.Name)) * 1000 / msElapsed
+			downDelta := netInterfaceDeltaTracker.Delta(fmt.Sprintf("%sdown", v.Name)) * 1000 / msElapsed
+			// add interface to systemStats
+			systemStats.NetworkInterfaces[v.Name] = [4]uint64{upDelta, downDelta, v.BytesSent, v.BytesRecv}
+		}
+
+		// add to systemStats
+		var bytesSentPerSecond, bytesRecvPerSecond uint64
+		if msElapsed > 0 {
+			bytesSentPerSecond = (totalBytesSent - a.netIoStats.BytesSent) * 1000 / msElapsed
+			bytesRecvPerSecond = (totalBytesRecv - a.netIoStats.BytesRecv) * 1000 / msElapsed
+		}
+		networkSentPs := bytesToMegabytes(float64(bytesSentPerSecond))
+		networkRecvPs := bytesToMegabytes(float64(bytesRecvPerSecond))
+		// add check for issue (#150) where sent is a massive number
+		if networkSentPs > 10_000 || networkRecvPs > 10_000 {
+			slog.Warn("Invalid net stats. Resetting.", "sent", networkSentPs, "recv", networkRecvPs)
+			for _, v := range netIO {
+				if _, exists := a.netInterfaces[v.Name]; !exists {
+					continue
+				}
+				slog.Info(v.Name, "recv", v.BytesRecv, "sent", v.BytesSent)
+			}
+			// reset network I/O stats
+			a.initializeNetIoStats()
+		} else {
+			systemStats.NetworkSent = networkSentPs
+			systemStats.NetworkRecv = networkRecvPs
+			systemStats.Bandwidth[0], systemStats.Bandwidth[1] = bytesSentPerSecond, bytesRecvPerSecond
+			// update netIoStats
+			a.netIoStats.BytesSent = totalBytesSent
+			a.netIoStats.BytesRecv = totalBytesRecv
+		}
+	}
+}
+
 func (a *Agent) initializeNetIoStats() {
 	// reset valid network interfaces
 	a.netInterfaces = make(map[string]struct{}, 0)