Comment 11 for bug 1555258

Excerpts from mynrpe-server's /var/log/syslog when running check_nrpe from mynagios-master (nrpe.cfg debug=1):

Before install of xenial recompiled package:

ubuntu@mynagios-master:~$ sudo -unagios /usr/lib/nagios/plugins/check_nrpe -H 192.168.1.12 -p 5664 -c check_procs -a rsyslogd 1 0
CHECK_NRPE: Received 0 bytes from daemon. Check the remote server logs for error messages.

May 1 20:20:06 mynrpe-server nrpe[83523]: Connection from 192.168.1.52 port 43186
May 1 20:20:06 mynrpe-server nrpe[83523]: Host address is in allowed_hosts
May 1 20:20:06 mynrpe-server nrpe[83523]: Handling the connection...
May 1 20:20:06 mynrpe-server nrpe[83523]: Error: Request contained command arguments!
May 1 20:20:06 mynrpe-server nrpe[83523]: Client request was invalid, bailing out...

After install of xenial recompiled package but nrpe.cfg dont_blame_nrpe=0 as installed (default):

ubuntu@mynagios-master:~$ sudo -unagios /usr/lib/nagios/plugins/check_nrpe -H 192.168.1.12 -p 5664 -c check_procs -a rsyslogd 1 0
CHECK_NRPE: Received 0 bytes from daemon. Check the remote server logs for error messages.

May 1 20:22:02 mynrpe-server nrpe[84181]: Handling the connection...
May 1 20:22:02 mynrpe-server nrpe[84181]: Error: Request contained command arguments, but argument option is not enabled!
May 1 20:22:02 mynrpe-server nrpe[84181]: Client request was invalid, bailing out...

After nrpe.cfg dont_blame_nrpe=1 (user is manually enabling command-args):

May 1 20:23:31 mynrpe-server nrpe[84324]: Server listening on 0.0.0.0 port 5664.
May 1 20:23:31 mynrpe-server nrpe[84324]: Server listening on :: port 5664.
May 1 20:23:31 mynrpe-server nrpe[84324]: Warning: Daemon is configured to accept command arguments from clients!
May 1 20:23:31 mynrpe-server nrpe[84324]: Listening for connections on port 0
May 1 20:23:31 mynrpe-server nrpe[84324]: Allowing connections from: 127.0.0.1,192.168.1.28,192.168.1.29,192.168.1.52

ubuntu@mynagios-master:~$ sudo -unagios /usr/lib/nagios/plugins/check_nrpe -H 192.168.1.12 -p 5664 -c check_procs -a rsyslogd 1 0
PROCS CRITICAL: 1 process with command name 'rsyslogd' | procs=1;1;0;0;

May 1 20:24:46 mynrpe-server nrpe[84858]: Running command: /usr/lib/nagios/plugins/check_procs -C rsyslogd -w 1 -c 0
May 1 20:24:46 mynrpe-server nrpe[84858]: Command completed with return code 2 and output: PROCS CRITICAL: 1 process with command name 'rsyslogd' | procs=1;1;0;0;
May 1 20:24:46 mynrpe-server nrpe[84858]: Return Code: 2, Output: PROCS CRITICAL: 1 process with command name 'rsyslogd' | procs=1;1;0;0;