go-netflow

go-netflow

go-netflow, capture process in/out traffic, similar to c Nethogs.

使用 golang 实现进程级流量监控

refer

refer logic design link

• https://zhuanlan.zhihu.com/p/49981590

refer nethogs source link

• https://github.com/raboof/nethogs

dep

yum install libpcap
yum install libpcap-devel

cli usage

netflow cli run:

go run cmd/main.go

stdout:

…

sdk simple usage:

package main

import (
	"encoding/json"
	"fmt"
	"time"

	"github.com/rfyiamcool/go-netflow"
)

func main() {
	nf, err := netflow.New(
		netflow.WithCaptureTimeout(5 * time.Second),
	)
	if err != nil {
		panic(err)
	}

	err = nf.Start()
	if err != nil {
		panic(err)
	}
	defer nf.Stop()

	<-nf.Done()

	var (
		limit     = 5
		recentSec = 5
	)

	rank, err := nf.GetProcessRank(limit, recentSec)
	if err != nil {
		panic(err)
	}

	bs, err := json.MarshalIndent(rank, "", "    ")
	if err != nil {
		panic(err)
	}

	fmt.Println(string(bs))
}

how to use sdk of go-netflow:

set pcap filename

Don't save pcap file by default.

WithStorePcap option is used to save pcap file, use tcpdump -nnr {filename} command to read pcap file.

WithStorePcap(fpath string)

set custom pcap bpf filter.

WithPcapFilter(filter string)

set custom pcap bpf filter.

example:

• host xiaorui.cc and port 80
• src host 123.56.223.52 and (dst port 3389 or 22)

WithPcapFilter(filter string)

limit netflow cpu/mem resource.

WithLimitCgroup(cpu float64, mem int)

set time to capturing packet.

WithCaptureTimeout(dur time.Duration)

set time to rescan process and inode data.

WithSyncInterval(dur time.Duration)

set the number of worker to consume pcap queue.

WithWorkerNum(num int)

set custom context.

WithCtx(ctx context.Context)

set custom devices to capture.

WithBindDevices(devs []string)

set pcap queue size. if the queue is full, new packet is thrown away.

WithQueueSize(size int)

types

netflow.Interface

type Interface interface {
	Start() error
	Stop()
	Done() <-chan struct{}
	LoadCounter() int64
	GetProcessRank(int, int) ([]*Process, error)
}

netflow.Process

type Process struct {
	Name         string
	Pid          string
	Exe          string
	State        string
	Inodes       []string
	TrafficStats *trafficStatsEntry
	Ring         []*trafficEntry
}

netflow.trafficStatsEntry

type trafficStatsEntry struct {
	In         int64 `json:"in"`
	Out        int64 `json:"out"`
	InRate     int64 `json:"in_rate"`
	OutRate    int64 `json:"out_rate"`
	InputEWMA  int64 `json:"input_ewma" valid:"-"`
	OutputEWMA int64 `json:"output_ewma" valid:"-"`
}

netflow.trafficEntry

type trafficEntry struct {
	Timestamp int64 `json:"timestamp"`
	In        int64 `json:"in"`
	Out       int64 `json:"out"`
}