Agent Install Failed - SSLv3

[InscrutableDude]

Hi,

I'm trying to install the agent on Ubuntu 16.04. I get the following error:

libnpcommon.a(sslutils.o): In function `np_net_ssl_init_with_hostname_version_and_cert':
/tmp/linux-nrpe-agent/subcomponents/nagiosplugins/nagios-plugins-2.0.3/plugins/sslutils.c:69: undefined reference to `SSLv3_client_method'
collect2: error: ld returned 1 exit status
Makefile:1674: recipe for target 'check_http' failed
make[1]: *** [check_http] Error 1
make[1]: Leaving directory '/tmp/linux-nrpe-agent/subcomponents/nagiosplugins/nagios-plugins-2.0.3/plugins'
Makefile:1415: recipe for target 'install-recursive' failed
make: *** [install-recursive] Error 1

This is evidently a known thing: https://askubuntu.com/questions/774760/ ... ot-working
Ubuntu has specifically disabled SSLv3.

So, what to do? I'm not about to custom build stuff for a production server.
I also tried removing the offending lines from the offending file (sslutils.c), but they come back. How do I get around this? The strange thing is, I have installed this on aother server with the same version OS, and it was fine.

Thanks in advance for any help or advice.

[tgriep]

There is a newer version on the Linux Agent (NRPE) that should compile on your Ubuntu 16.04 system.
The following link are the instructions you can use to install NRPE version 3.x.x
https://support.nagios.com/kb/article.php?id=515
Try using this version and let us know if it works for you.

[InscrutableDude]

Well, all went ok until this step:

Update Configuration File
The file nrpe.cfg is where the following settings will be defined. It is located:

CentOS | RHEL | Ubuntu | Fedora | SUSE SLES | openSUSE | Solaris | Oracle Linux | FreeBSD

/usr/local/nagios/etc/nrpe.cfg

The file doesn't exist. I did follow all previous steps, and running as root. Problem is I can't modify a file that doesn't exist.

Any thoughts appreciated.

[tgriep]

During the installation, you should have run this command to install the configuration files.

Code: Select all

sudo make install-config

Try running that again and see if that copies the nrpe.cfg file over.
Any errors, please post them.

[InscrutableDude]

Thanks! I'm not sure why the config file didn't get done the first time, but it's working now. Agent and plugins are all installed and working.

[InscrutableDude]

I should mention that the plugins do not all get installed with the steps outlined. When I enabled monitoring, most of the tests error out with things like "NRPE: Command 'check_procs' not defined"

I'm enabling the include_dir option and manually creating that nrpe folder in /usr/local/nagios/etc, then rsync'ing the files over. Hope it works

[InscrutableDude]

Ok, so, I was able to make check_mem work by copying the custom check mem script from one server to this one. The others however are a problem. They've gone from being CRITICAL to being UNKNOWN:

NRPE: Unable to read output

This is for
CPU Stats
MySQL Server
Open Files
SSH Server

All the definitions seem to be there, and I restarted the nrpe service, bit no joy. Any ideas?

**EDIT: Also note that I went back and deleted the services and the host and redid it. Still no luck

[tgriep]

It sounds like the command definitions may not be setup correctly on the remote server, In the code block below, are the commands that should work for your Nagios server.

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### GENERIC SERVICES ###
command[check_init_service]=sudo /usr/local/nagios/libexec/check_init_service $ARG1$
command[check_services]=/usr/local/nagios/libexec/check_services -p $ARG1$

### MISC SYSTEM METRICS ###
#command[check_users]=/usr/local/nagios/libexec/check_users -w 5 -c 10
command[check_users]=/usr/local/nagios/libexec/check_users $ARG1$
command[check_load]=/usr/local/nagios/libexec/check_load $ARG1$
command[check_swap]=/usr/local/nagios/libexec/check_swap $ARG1$
command[check_cpu_stats]=/usr/local/nagios/libexec/check_cpu_stats.sh $ARG1$
#command[check_mem]=/usr/local/nagios/libexec/custom_check_mem -n $ARG1$
command[check_mem]=/usr/local/nagios/libexec/custom_check_mem $ARG1$

### SYSTEM UPDATES ###
command[check_yum]=/usr/local/nagios/libexec/check_yum
command[check_apt]=/usr/local/nagios/libexec/check_apt

### DISK ###
command[check_disk]=/usr/local/nagios/libexec/check_disk $ARG1$
command[check_ide_smart]=/usr/local/nagios/libexec/check_ide_smart $ARG1$

### PROCESSES ###
command[check_all_procs]=/usr/local/nagios/libexec/custom_check_procs
command[check_procs]=/usr/local/nagios/libexec/check_procs $ARG1$

### OPEN FILES ###
command[check_open_files]=/usr/local/nagios/libexec/check_open_files.pl $ARG1$

### NETWORK CONNECTIONS ###
command[check_netstat]=/usr/local/nagios/libexec/check_netstat.pl -p $ARG1$ $ARG2$

After changing the commands, you will have to restart the NRPE Agent and the checks should work unless the plugin is missing.

[InscrutableDude]

I entirely replaced the contends of nrpe/common.cfg with your code. no go. I then commented out the include directory and pasted directly into nrpe.cfg. Still nothing. And NRPE is installed and working. The nrpe.cfg file had hardcoded settings, and those worked:

Code: Select all

command[check_users]=/usr/local/nagios/libexec/check_users -w 5 -c 10
command[check_load]=/usr/local/nagios/libexec/check_load -w 15,10,5 -c 30,25,20
command[check_hda1]=/usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/hda1
command[check_zombie_procs]=/usr/local/nagios/libexec/check_procs -w 5 -c 10 -s Z
command[check_total_procs]=/usr/local/nagios/libexec/check_procs -w 150 -c 200

The stuff with ARG1 etc seems to not work. Is there a log I should be checking to see where it's fouling up?

[tgriep]

Can you post the /usr/local/nagios/etc/nrpe.cfg file from the remote server and how the checks are configured from the Nagios XI server?
The arguments should work for NRPE but if this option in the nrpe.cfg file
dont_blame_nrpe=1
if not set to a 1 then it would cause the error you are having.
Make sure it is set to a 1 and restart the NRPE agent and see if it works for you.