Increase ping timeout based on ping count and interval

[kodek]

This should fix a bug where the ping command will time out when specifying ping count > 1 with a long interval. Feel free to rewrite and/or add tests if necessary.

[sparrc]

seems more like user-error to me, why don't you just increase the timeout?

I'd prefer the plugin to behave the same as the ping unix command.

[kodek]

The timeout parameter is used both for the -W argument in ping (a per-ping timeout, "time to wait for a response" from the man pages) and the total ping command exec timeout (via internal.CombinedOutputTimeout()). You can reproduce the bug by passing in the following parameters:

count = 4
ping_interval = 15.0
timeout = 1.0

It will fail due to "Command timed out."

The corresponding ping command does not time out when sent from a terminal:
$ ping -c 4 -n -s 16 -i 15 -W 1 google.com

[sparrc]

hmm I see. I think that this plugin was meant to be using the -w flag instead of -W. I'm not sure whether we should change that to -w or patch the current behavior as your PR does.

[kodek]

I see that some checks failed (maybe just formatting-related?). Could I defer any further changes to you?

Regarding -w vs -W, either approach is fine. If you decide to use -w, could you add a comment on the sample config or the type definition?

Thank you!

[sparrc]

could you just run go fmt ./... on the code? it's a standard Go practice and needs to be done before tests can run

[sparrc]

closing for #1359