cmd/root.go
// Copyright © 2019 Vyacheslav Akhmetov <iam@itaddict.ru>
package cmd
import (
"fmt"
"github.com/akme/get-closer/loaders"
"github.com/akme/get-closer/protocols"
"net"
"os"
"time"
homedir "github.com/mitchellh/go-homedir"
"github.com/spf13/cobra"
"github.com/spf13/viper"
"gopkg.in/cheggaaa/pb.v1"
"math"
"sort"
)
var (
cfgFile string
hostsFile string
timeout uint // time.Duration( 10 * time.Second)
concurrency uint
limit uint
dnsResolver string
dnsWarmUp bool
progressBar bool
count int
verbose bool
sslEnable bool
tcpPort int
delay int
)
// rootCmd represents the base command when called without any subcommands
var rootCmd = &cobra.Command{
Use: "get-closer",
Short: "Find out closest hosts in terms of network latency.",
Long: `Find out closest hosts in terms of network latency.`,
// Uncomment the following line if your bare application
// has an action associated with it:
// Run: func(cmd *cobra.Command, args []string) { },
}
// Execute adds all child commands to the root command and sets flags appropriately.
// This is called by main.main(). It only needs to happen once to the rootCmd.
func Execute() {
if err := rootCmd.Execute(); err != nil {
fmt.Println(err)
os.Exit(1)
}
}
func init() {
cobra.OnInitialize(initConfig)
// Here you will define your flags and configuration settings.
// Cobra supports persistent flags, which, if defined here,
// will be global for your application.
rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default: ~/.get-closer.yaml)")
rootCmd.PersistentFlags().StringVarP(&hostsFile, "from-file", "f", "", "path to file with hosts to check")
rootCmd.MarkPersistentFlagRequired("from-file")
rootCmd.PersistentFlags().UintVarP(&timeout, "timeout", "t", 60, "timeout for request")
rootCmd.PersistentFlags().UintVarP(&concurrency, "concurrency", "c", 1, "concurrency")
rootCmd.PersistentFlags().UintVarP(&limit, "limit", "l", 0, "number of hosts to return")
rootCmd.PersistentFlags().StringVarP(&dnsResolver, "dns-resolver", "r", "", "use custom DNS resolver")
rootCmd.PersistentFlags().BoolVarP(&dnsWarmUp, "dns-warm-up", "w", true, "warm up DNS cache before request")
rootCmd.PersistentFlags().IntVarP(&count, "count", "", 1, "number of tests per host")
rootCmd.PersistentFlags().BoolVarP(&progressBar, "progress-bar", "b", true, "show progress bar")
rootCmd.PersistentFlags().BoolVarP(&verbose, "verbose", "v", false, "enable verbose mode")
rootCmd.PersistentFlags().IntVarP(&delay, "delay", "d", 3, "set delay between checks")
// Cobra also supports local flags, which will only run
// when this action is called directly.
}
// initConfig reads in config file and ENV variables if set.
func initConfig() {
if cfgFile != "" {
// Use config file from the flag.
viper.SetConfigFile(cfgFile)
} else {
// Find home directory.
home, err := homedir.Dir()
if err != nil {
fmt.Println(err)
os.Exit(1)
}
// Search config in home directory with name ".get-closer" (without extension).
viper.AddConfigPath(home)
viper.SetConfigName(".get-closer")
}
viper.AutomaticEnv() // read in environment variables that match
// If a config file is found, read it in.
if err := viper.ReadInConfig(); err == nil {
fmt.Println("Using config file:", viper.ConfigFileUsed())
}
viper.BindPFlag("from-file", rootCmd.PersistentFlags().Lookup("from-file"))
viper.BindPFlag("timeout", rootCmd.PersistentFlags().Lookup("timeout"))
viper.BindPFlag("concurrency", rootCmd.Flags().Lookup("concurrency"))
viper.BindPFlag("limit", rootCmd.PersistentFlags().Lookup("limit"))
viper.BindPFlag("dns-server", rootCmd.PersistentFlags().Lookup("dns-server"))
viper.BindPFlag("dns-warm-up", rootCmd.PersistentFlags().Lookup("dns-warm-up"))
}
//durationSlice represents collection of measurements
type durationSlice []time.Duration
//Measurement struct for storing results
type Measurement struct {
Host string
Duration durationSlice
}
//Measurements list
type Measurements []Measurement
func (m Measurements) Len() int { return len(m) }
func (m Measurements) Less(i, j int) bool { return m[i].Duration.Avg() > m[j].Duration.Avg() }
func (m Measurements) Swap(i, j int) { m[i], m[j] = m[j], m[i] }
func startMeasurements(ccmd *cobra.Command, args []string) {
hostsList, err := loaders.LoadHosts(hostsFile)
if err != nil {
fmt.Println(err)
}
var MeasurementsList Measurements
for _, v := range hostsList {
MeasurementsList = append(MeasurementsList, Measurement{Host: v})
}
listSize := len(MeasurementsList)
bar := pb.New(listSize)
if progressBar {
bar = pb.StartNew(listSize).Prefix("Checking hosts")
bar.ShowTimeLeft = false
}
if len(dnsResolver) != 0 {
protocols.UseCustomDNS([]string{dnsResolver})
}
for k, v := range MeasurementsList {
if verbose {
fmt.Printf("Measuring [%d/%d] %s\n", k+1, listSize, v.Host)
}
if progressBar {
bar.Increment()
}
var duration time.Duration
if err != nil {
fmt.Println("url.Parse:", err)
}
if dnsWarmUp {
if verbose {
fmt.Printf("\tWarming up DNS for %s\n", v.Host)
}
before := time.Now()
addrs, err := net.LookupHost(v.Host)
diff := time.Since(before)
if err != nil {
fmt.Println(err)
continue
}
if verbose {
fmt.Printf("\tResolving %s to %s took %s\n", v.Host, addrs, diff)
}
}
for i := 0; i < count; i++ {
switch ccmd.Name() {
case "http":
duration = protocols.HTTPPing(v.Host, sslEnable)
case "dns":
duration = protocols.DNSPing(v.Host)
case "icmp":
duration = protocols.ICMPPing(v.Host)
case "tcp":
duration = protocols.TCPPing(v.Host, tcpPort)
default:
}
if err != nil {
fmt.Println(err)
}
if verbose {
fmt.Printf("\t%s measurement for %s took %s\n", ccmd.Name(), v.Host, duration)
}
MeasurementsList[k].Duration = append(MeasurementsList[k].Duration, duration)
time.Sleep(time.Duration(delay) * time.Second)
}
}
if progressBar {
bar.FinishPrint("Closest hosts:")
}
if verbose {
fmt.Println("Closest hosts:")
}
if limit == 0 {
limit = uint(listSize)
}
sortedList := sortByDuration(MeasurementsList)
for _, v := range sortedList[:limit] {
fmt.Printf("\t%s %s\n", v.Host, v.Duration)
}
}
func (p durationSlice) Len() int { return len(p) }
func (p durationSlice) Less(i, j int) bool { return int64(p[i]) < int64(p[j]) }
func (p durationSlice) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
func (p durationSlice) Min() time.Duration {
sort.Sort(p)
return p[0]
}
func (p durationSlice) Max() time.Duration {
sort.Sort(p)
return p[p.Len()-1]
}
func (p durationSlice) Avg() time.Duration {
var avg int64
for i := 0; i < p.Len(); i++ {
avg += int64(p[i])
}
if p.Len() == 0 {
return time.Duration(0)
}
return time.Duration(avg / int64(p.Len()))
}
func (p durationSlice) Std() time.Duration {
sqdifs := make(durationSlice, p.Len(), p.Len())
avg := p.Avg()
var avgsqdif int64
for i := 0; i < p.Len(); i++ {
sqdif := p[i] - avg
sqdifs[i] = sqdif * sqdif
avgsqdif += int64(sqdifs[i])
}
avgsqdif /= int64(sqdifs.Len())
return time.Duration(math.Sqrt(float64(avgsqdif)))
}
func sortByDuration(measurements Measurements) Measurements {
pl := make(Measurements, len(measurements))
i := 0
for _, v := range measurements {
pl[i] = Measurement{v.Host, durationSlice{v.Duration.Avg()}}
i++
}
sort.Sort(sort.Reverse(pl))
return pl
}