Set reasonable defaults in ping plugin

closes #1742

plugins/inputs/ping/ping.go

@@ -52,13 +52,13 @@ const sampleConfig = `
  ## urls to ping
  urls = ["www.google.com"] # required
  ## number of pings to send per collection (ping -c <COUNT>)
- count = 1 # required
+ # count = 1
  ## interval, in s, at which to ping. 0 == default (ping -i <PING_INTERVAL>)
- ping_interval = 0.0
+ # ping_interval = 0.0
  ## per-ping timeout, in s. 0 == no timeout (ping -W <TIMEOUT>)
- timeout = 1.0
+ # timeout = 1.0
  ## interface to send ping from (ping -I <INTERFACE>)
- interface = ""
+ # interface = ""
 `
 
 func (_ *Ping) SampleConfig() string {
@@ -200,6 +200,11 @@ func processPingOutput(out string) (int, int, float64, error) {
 
 func init() {
  inputs.Add("ping", func() telegraf.Input {
- return &Ping{pingHost: hostPinger}
+ return &Ping{
+ pingHost: hostPinger,
+ PingInterval: 0.0,
+ Count: 1,
+ Timeout: 1.0,
+ }
  })
 }