telegraf/plugins/ping/ping.go

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2015-09-02 23:16:52 +00:00
package ping
import (
"errors"
"os/exec"
"strconv"
"strings"
"sync"
"github.com/influxdb/telegraf/plugins"
)
// 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(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 -t <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"
}
var sampleConfig = `
# urls to ping
urls = ["www.google.com"] # required
# number of pings to send (ping -c <COUNT>)
count = 1 # required
# interval, in s, at which to ping. 0 == default (ping -i <PING_INTERVAL>)
ping_interval = 0.0
# ping timeout, in s. 0 == no timeout (ping -t <TIMEOUT>)
timeout = 0.0
# interface to send ping from (ping -I <INTERFACE>)
interface = ""
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`
func (_ *Ping) SampleConfig() string {
return sampleConfig
}
func (p *Ping) Gather(acc plugins.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(url string, acc plugins.Accumulator) {
defer wg.Done()
args := p.args(url)
out, err := p.pingHost(args...)
if err != nil {
// Combine go err + stderr output
errorChannel <- errors.New(
strings.TrimSpace(out) + ", " + err.Error())
}
tags := map[string]string{"url": url}
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
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fields := map[string]interface{}{
"packets_transmitted": trans,
"packets_received": rec,
"percent_packet_loss": loss,
"average_response_ms": avg,
}
acc.AddFields("ping", fields, tags)
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}(url, acc)
}
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(args ...string) (string, error) {
c := exec.Command("ping", args...)
out, err := c.CombinedOutput()
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)}
if p.PingInterval > 0 {
args = append(args, "-i", strconv.FormatFloat(p.PingInterval, 'f', 1, 64))
}
if p.Timeout > 0 {
args = append(args, "-t", 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() {
plugins.Add("ping", func() plugins.Plugin {
return &Ping{pingHost: hostPinger}
})
}