Ping does not run with permission denied error

[manios]

ping command does not run as it requires root privileges in Alpine. We run Nagios with a specific user nagios. To overcome this burden we are going to run ping using gosu utility.

More references:

1. https://askubuntu.com/questions/453377/how-to-enable-event-mpm-apache-2-4-on-ubuntu-14-04-with-thread-safe-php
2. Issue with supported formatting commands for "ps" gliderlabs/docker-alpine#173
3. ping: permission denied (are you root?) smebberson/docker-alpine#65
4. https://serverfault.com/questions/238962/how-do-i-clear-the-s-permission-on-a-directory-in-linux
5. https://www.linuxnix.com/suid-set-suid-linuxunix/
6. https://sourceforge.net/p/nagios/mailman/message/19832020/

Furthermore when we run :

/opt/nagios $ /bin/gosu root /bin/ping localhost
error: failed switching to "root": operation not permitted

inside an ARMv6 or ARMv6 Docker container which runs with QEmu, then this is due to the fact
qemu-user-static/#17 and we need to run

docker run --rm --privileged multiarch/qemu-user-static:register --reset --credential yes

so it works.