nagios incompatible with busybox's ping
I was just trying to pack nagios into a alpine-3.7-based docker images with the nagios packages coming with alpine, and ran into an alpine-specific problem: nagios kept complaining that it could not parse the output of the /bin/ping command and thus the ping test failed permanently.
Reason: On common linux machines /bin/ping is a binary with u+s (setuid root) to allow all users to send ping packages. In contrast, on alpine it is just a symlink to busybox, which does the same job, but does not have the setuid bit set. A simple chmod u+s /bin/busybox solves the problem, nagios then works, but it obviously opens a hell of security problems when all commands implemented by busybox have a suid bit.
(from redmine: issue id 8768, created on 2018-04-05)