This seams to be an endless story; the container is up, but I guess the main problem exists on my docker host – There is still a permission issue.
root@740c245f6e84:/opt/omd/versions/2.0.0p8.cre/lib/nagios/plugins# ./check_icmp 192.168.7.254
OK - 192.168.7.254: rta 0.301ms, lost 0%|rta=0.301ms;200.000;500.000;0; pl=0%;40;80;; rtmax=0.492ms;;;; rtmin=0.241ms;;;;
root@740c245f6e84:/opt/omd/versions/2.0.0p8.cre/lib/nagios/plugins# sudo -u cmk ./check_icmp 192.168.7.254
check_icmp: Failed to obtain ICMP socket: Operation not permitted
Didn’t get it right now.
root@740c245f6e84:/opt/omd/versions/2.0.0p8.cre/lib/nagios/plugins# ls -la |grep check_icmp
-rwxr-x--- 1 root omd 64648 Jul 20 10:15 check_icmp
root@740c245f6e84:/opt/omd/versions/2.0.0p8.cre/lib/nagios/plugins# getcap check_icmp
check_icmp = cap_net_raw+ep
root@740c245f6e84:/opt/omd/versions/2.0.0p8.cre/lib/nagios/plugins# attr -l check_icmp
Attribute "capability" has a 20 byte value for check_icmp
Maybe someone has an idea? just to clarify what this caused.
root yes - user no … 
Solution: A new deployment. Thanks for reading! 