Function getNetworkInterfaceStats

libcontainer/network_linux.go:45–78

Returns the network statistics for the network interfaces represented by the NetworkRuntimeInfo.

(interfaceName string)

// Returns the network statistics for the network interfaces represented by the NetworkRuntimeInfo.
func getNetworkInterfaceStats(interfaceName string) (*types.NetworkInterface, error) {
	out := &types.NetworkInterface{Name: interfaceName}
	// This can happen if the network runtime information is missing - possible if the
	// container was created by an old version of libcontainer.
	if interfaceName == "" {
		return out, nil
	}
	type netStatsPair struct {
		// Where to write the output.
		Out *uint64
		// The network stats file to read.
		File string
	}
	// Ingress for host veth is from the container. Hence tx_bytes stat on the host veth is actually number of bytes received by the container.
	netStats := []netStatsPair{
		{Out: &out.RxBytes, File: "tx_bytes"},
		{Out: &out.RxPackets, File: "tx_packets"},
		{Out: &out.RxErrors, File: "tx_errors"},
		{Out: &out.RxDropped, File: "tx_dropped"},

		{Out: &out.TxBytes, File: "rx_bytes"},
		{Out: &out.TxPackets, File: "rx_packets"},
		{Out: &out.TxErrors, File: "rx_errors"},
		{Out: &out.TxDropped, File: "rx_dropped"},
	}
	for _, netStat := range netStats {
		data, err := readSysfsNetworkStats(interfaceName, netStat.File)
		if err != nil {
			return nil, err
		}
		*(netStat.Out) = data
	}
	return out, nil
}

// Reads the specified statistics available under /sys/class/net/<EthInterface>/statistics
func readSysfsNetworkStats(ethInterface, statsFile string) (uint64, error) {