Allow check to look for either tcp4 or tcp6 port listening

[kwaio]

Hi,

A problem we regularily face is that sometimes, depending on software version, OS, OS version, etc. servers listen on ::, sometimes on 0.0.0.0, which makes writing gossfile quite complicated

(and led us to disable ipv6 on some hosts, which is not a good solution)

Is there any way to write a check that accepts either 0.0.0.0 OR :: ?

[aelsabbahy]

1. Love the name.

This issue has been a pain for quite a while. I've been looking for some help on how to handle this, there's an issue open with a more thorough discussion of the problem here #149

Do you know of any tool that handles this cleanly? If so, please add a comment to issue #149