Export network stats via runsc events.

The stats have been collected via cAdvisor which is being deprecated.

This change dosen't migrate the metric.

PiperOrigin-RevId: 625835710

runsc/boot/events.go

@@ -23,6 +23,20 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/usage"
 )
 
+// NetworkInterface is the network statistics of the particular network interface
+type NetworkInterface struct {
+	// Name is the name of the network interface.
+	Name      string
+	RxBytes   uint64
+	RxPackets uint64
+	RxErrors  uint64
+	RxDropped uint64
+	TxBytes   uint64
+	TxPackets uint64
+	TxErrors  uint64
+	TxDropped uint64
+}
+
 // EventOut is the return type of the Event command.
 type EventOut struct {
 	Event Event `json:"event"`
@@ -42,9 +56,10 @@ type Event struct {
 // Stats is the runc specific stats structure for stability when encoding and
 // decoding stats.
 type Stats struct {
-	CPU    CPU    `json:"cpu"`
-	Memory Memory `json:"memory"`
-	Pids   Pids   `json:"pids"`
+	CPU               CPU                 `json:"cpu"`
+	Memory            Memory              `json:"memory"`
+	Pids              Pids                `json:"pids"`
+	NetworkInterfaces []*NetworkInterface `json:"network_interfaces"`
 }
 
 // Pids contains stats on processes.
@@ -127,6 +142,12 @@ func (cm *containerManager) Event(cid *string, out *EventOut) error {
 	}
 	out.Event.Data.Pids.Current = uint64(pids)
 
+	networkStats, err := cm.l.networkStats()
+	if err != nil {
+		return err
+	}
+	out.Event.Data.NetworkInterfaces = networkStats
+
 	numContainers := cm.l.containerCount()
 	if numContainers == 0 {
 		return fmt.Errorf("no container was found")

runsc/boot/loader.go

@@ -1718,3 +1718,26 @@ func (l *Loader) pidsCount(cid string) (int, error) {
 	}
 	return l.k.TaskSet().Root.NumTasksPerContainer(cid), nil
 }
+
+func (l *Loader) networkStats() ([]*NetworkInterface, error) {
+	var stats []*NetworkInterface
+	stack := l.k.RootNetworkNamespace().Stack()
+	for _, i := range stack.Interfaces() {
+		var stat inet.StatDev
+		if err := stack.Statistics(&stat, i.Name); err != nil {
+			return nil, err
+		}
+		stats = append(stats, &NetworkInterface{
+			Name:      i.Name,
+			RxBytes:   stat[0],
+			RxPackets: stat[1],
+			RxErrors:  stat[2],
+			RxDropped: stat[3],
+			TxBytes:   stat[8],
+			TxPackets: stat[9],
+			TxErrors:  stat[10],
+			TxDropped: stat[11],
+		})
+	}
+	return stats, nil
+}