telegraf/plugins/inputs/ping/ping.go

206 lines
5.6 KiB
Go

// +build !windows
package ping
import (
"errors"
"os/exec"
"runtime"
"strconv"
"strings"
"sync"
"time"
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/internal"
"github.com/influxdata/telegraf/plugins/inputs"
)
// HostPinger is a function that runs the "ping" function using a list of
// passed arguments. This can be easily switched with a mocked ping function
// for unit test purposes (see ping_test.go)
type HostPinger func(timeout float64, args ...string) (string, error)
type Ping struct {
// Interval at which to ping (ping -i <INTERVAL>)
PingInterval float64 `toml:"ping_interval"`
// Number of pings to send (ping -c <COUNT>)
Count int
// Ping timeout, in seconds. 0 means no timeout (ping -W <TIMEOUT>)
Timeout float64
// Interface to send ping from (ping -I <INTERFACE>)
Interface string
// URLs to ping
Urls []string
// host ping function
pingHost HostPinger
}
func (_ *Ping) Description() string {
return "Ping given url(s) and return statistics"
}
const sampleConfig = `
## NOTE: this plugin forks the ping command. You may need to set capabilities
## via setcap cap_net_raw+p /bin/ping
#
## urls to ping
urls = ["www.google.com"] # required
## number of pings to send per collection (ping -c <COUNT>)
count = 1 # required
## interval, in s, at which to ping. 0 == default (ping -i <PING_INTERVAL>)
ping_interval = 0.0
## per-ping timeout, in s. 0 == no timeout (ping -W <TIMEOUT>)
timeout = 1.0
## interface to send ping from (ping -I <INTERFACE>)
interface = ""
`
func (_ *Ping) SampleConfig() string {
return sampleConfig
}
func (p *Ping) Gather(acc telegraf.Accumulator) error {
var wg sync.WaitGroup
errorChannel := make(chan error, len(p.Urls)*2)
// Spin off a go routine for each url to ping
for _, url := range p.Urls {
wg.Add(1)
go func(u string) {
defer wg.Done()
args := p.args(u)
totalTimeout := float64(p.Count)*p.Timeout + float64(p.Count-1)*p.PingInterval
out, err := p.pingHost(totalTimeout, args...)
if err != nil {
// Combine go err + stderr output
errorChannel <- errors.New(
strings.TrimSpace(out) + ", " + err.Error())
}
tags := map[string]string{"url": u}
trans, rec, avg, err := processPingOutput(out)
if err != nil {
// fatal error
errorChannel <- err
return
}
// Calculate packet loss percentage
loss := float64(trans-rec) / float64(trans) * 100.0
fields := map[string]interface{}{
"packets_transmitted": trans,
"packets_received": rec,
"percent_packet_loss": loss,
}
if avg > 0 {
fields["average_response_ms"] = avg
}
acc.AddFields("ping", fields, tags)
}(url)
}
wg.Wait()
close(errorChannel)
// Get all errors and return them as one giant error
errorStrings := []string{}
for err := range errorChannel {
errorStrings = append(errorStrings, err.Error())
}
if len(errorStrings) == 0 {
return nil
}
return errors.New(strings.Join(errorStrings, "\n"))
}
func hostPinger(timeout float64, args ...string) (string, error) {
bin, err := exec.LookPath("ping")
if err != nil {
return "", err
}
c := exec.Command(bin, args...)
out, err := internal.CombinedOutputTimeout(c,
time.Second*time.Duration(timeout+1))
return string(out), err
}
// args returns the arguments for the 'ping' executable
func (p *Ping) args(url string) []string {
// Build the ping command args based on toml config
args := []string{"-c", strconv.Itoa(p.Count), "-n", "-s", "16"}
if p.PingInterval > 0 {
args = append(args, "-i", strconv.FormatFloat(p.PingInterval, 'f', 1, 64))
}
if p.Timeout > 0 {
switch runtime.GOOS {
case "darwin":
args = append(args, "-W", strconv.FormatFloat(p.Timeout/1000, 'f', 1, 64))
case "linux":
args = append(args, "-W", strconv.FormatFloat(p.Timeout, 'f', 1, 64))
default:
// Not sure the best option here, just assume GNU ping?
args = append(args, "-W", strconv.FormatFloat(p.Timeout, 'f', 1, 64))
}
}
if p.Interface != "" {
args = append(args, "-I", p.Interface)
}
args = append(args, url)
return args
}
// processPingOutput takes in a string output from the ping command, like:
//
// PING www.google.com (173.194.115.84): 56 data bytes
// 64 bytes from 173.194.115.84: icmp_seq=0 ttl=54 time=52.172 ms
// 64 bytes from 173.194.115.84: icmp_seq=1 ttl=54 time=34.843 ms
//
// --- www.google.com ping statistics ---
// 2 packets transmitted, 2 packets received, 0.0% packet loss
// round-trip min/avg/max/stddev = 34.843/43.508/52.172/8.664 ms
//
// It returns (<transmitted packets>, <received packets>, <average response>)
func processPingOutput(out string) (int, int, float64, error) {
var trans, recv int
var avg float64
// Set this error to nil if we find a 'transmitted' line
err := errors.New("Fatal error processing ping output")
lines := strings.Split(out, "\n")
for _, line := range lines {
if strings.Contains(line, "transmitted") &&
strings.Contains(line, "received") {
err = nil
stats := strings.Split(line, ", ")
// Transmitted packets
trans, err = strconv.Atoi(strings.Split(stats[0], " ")[0])
if err != nil {
return trans, recv, avg, err
}
// Received packets
recv, err = strconv.Atoi(strings.Split(stats[1], " ")[0])
if err != nil {
return trans, recv, avg, err
}
} else if strings.Contains(line, "min/avg/max") {
stats := strings.Split(line, " = ")[1]
avg, err = strconv.ParseFloat(strings.Split(stats, "/")[1], 64)
if err != nil {
return trans, recv, avg, err
}
}
}
return trans, recv, avg, err
}
func init() {
inputs.Add("ping", func() telegraf.Input {
return &Ping{pingHost: hostPinger}
})
}