Unfortunately I'm still getting "Unable to run check for service" on all service checks because they're blocked by SELinux with errors like this one:

type=AVC msg=audit(1507311527.812:31135): avc: denied { execute_no_trans } for pid=16333 comm="nagios" path="/usr/sbin/nagios" dev=cciss!c0d0p3 ino=1317059 scontext=unconfined_u:system_r:nagios_t:s0 tcontext=system_u:object_r:nagios_exec_t:s0 tclass=file

It only happens if I run nagios with service nagios start. If I run it with /usr/sbin/nagios -d /etc/nagios/nagios.cfg it works so it would seem that the issue is based on whether nagios is running as the nagios user or as root.

My other SELinux problem with writing to /tmp is fixed.

BTW, the following type enforcement module fixes the problem:

` module jobmatch_nagios 1.0;

require { type nagios_t; type nagios_exec_t; class file execute_no_trans; }

============= nagios_t ==============

allow nagios_t nagios_exec_t:file execute_no_trans; `

Shoot my formatting got all messed up. Here it is again:

module jobmatch_nagios 1.0;

require {
    type nagios_t;
    type nagios_exec_t;
    class file execute_no_trans;
}

#============= nagios_t ==============
allow nagios_t nagios_exec_t:file execute_no_trans;

Can you do a audit2allow -v or similar to see why it needs that? I can't replicate on my 6 systems at the moment.

Hmm, this is all that audit2allow -v gives me. Is there anything else I can run to get you more info? Thanks

#============= nagios_t ==============
# src="nagios_t" tgt="nagios_exec_t" class="file", perms="execute_no_trans"
# comm="nagios" exe="" path=""
#!!!! This avc is allowed in the current policy
allow nagios_t nagios_exec_t:file execute_no_trans;

Oh my gosh, I'm legitimately an idiot. Guess what the problem was? I didn't have the nagios-selinux package installed. :( I guess it wasn't required with the old version 3 EPEL nagios packages? I don't know. But now, with nagios-selinux installed and updated to 4.3.4-4, everything is working perfectly without any SELinux tweaks required. Awesome!!!

Thanks @smooge!!