Introduction

This document describes how to install NMIS9 on GNU/Linux systems.

Caveats

NMIS9 has been widely deployed and tested on many Linux distros, with Red Hat/CentOS being the most popular among  our customers. This document contains variations specific to several Linux distros, but not all of them have been tested equally heavily: Centos 6/7, Debian 8/9, Ubuntu LTS are our main platforms for in-house testing.

We do appreciate your feedback (and any modifications or changes) that you might submit to support@opmantek.com!

Assumptions

The reader is assumed to have a working knowledge of UNIX or GNU/Linux systems and what Perl is. While NMIS is written in Perl, you do not need to be a "Perl hacker" to install this program and make it work. Some fundamental knowledge of  how to compile software on UNIX systems would certainly be helpful, but is by no means required.

This document will use the <nmisdir> tag to refer to NMIS's installation directory (whose default is /usr/local/nmis9); the tag <version> stands for the full version of NMIS (at this time 9.1.1).

The Installation Process

Linux Distribution

First, install your GNU/Linux distribution of choice. It is recommended to select a basic installation type with no extra stuff. That means no GNOME, KDE, "Server" packages, or anything else.
Depending on your choice of distribution, the "minimal" installation type may not be totally sufficient for NMIS: with CentOS/Redhat 7 for example, "minimal" does not include Perl  and in this case you'll have to install the Perl core (using sudo yum install perl-core) before NMIS can be installed. (Versions 8.5.14G and newer will detect this situation and offer to install perl for you.)

Linux Security Settings: SELinux and Firewalling

We recommend that you turn off SELinux. Permissive mode was tested and it worked well, just very nagging; the default mode is known to interfere with NMIS. Disabling SELinux is a lot easier than performing  the extensive configuration that SELinux needs. To check if SELinux is disabled you can use the command getenforce. If SELinux is enabled in CentOS 6.8, an example of how to disable it is below:

Similarly, if you have a firewall on your server (e.g. iptables / firewalld ) you need to make sure that it accepts incoming HTTP (possibly HTTPS) connections, and SNMP traps and Syslog connections/packets. This involves incoming connections to TCP ports 80 and 443, and UDP ports 161, 162, and 514.  

NMIS9 Installation

As of February 2016, NMIS is distributed in a self-extracting download format that simplifies the installation process quite a bit. More information on installer options can be found HERE: The Opmantek Installer
You can download NMIS from the Opmantek website at https://opmantek.com/network-tools-download/; the distribution file is called nmis<version>.run, and your browser will likely prompt you regarding what to do with this '.run' file; you should tell it to Save the file, ideally in /tmp.

Starting the Installer

Please note that the installer must be run with superuser privileges; if you're not the root user you'll have to use sudo or su to switch privileges.

Starting the self-extracting installer is trivial: you simply tell your shell to run it, using one of two mechanisms:

1. The simplest way to achieve this is to type "sh ./nmis<version>.run"
2. You can also modify the permissions of the .run file to indicate that it is executable, then start it directly.
   To do so, you'd run "chmod u+x ./nmis<version>.run" followed by "./nmis<version>.run".

The installer will first run an archive integrity check, decompress the archive, then start the interactive phase of the installation. 

The installer takes care of all necessary operations on the supported platforms: all pre-requisite software is installed and configured, an existing NMIS installation is upgraded in place and basic integration of NMIS with the operating system is performed on your behalf as well.

The installer does require Internet access for installing pre-requisites using apt-get, yum and CPAN (but we do have a few suggestions for dealing with a system where Internet access is restricted).

As of 8.5.6G using the installer is the only supported method for installing or upgrading NMIS, because by now it  is now suitably mature and robust, and because it's very very easy to miss crucial operations in a totally manual installation. Please see the Advanced Installer Use section at the bottom if you need more precise control over the installer.

If the installer asks you about installing some Perl modules with CPAN...

...don't panic, this is more or less expected: not all Linux distributions provide readymade packages for all of NMIS' needs, thus certain modules require installation from CPAN, the "comprehensive perl archive network").

There is one important aspect regarding the initial configuration of the CPAN tool. Depending on your versions of Perl and the CPAN tool, and whether SELinux is enabled or not,  you may be asked about the "approach for installing modules" in a dialog  similar to this example:

Warning: You do not have write permission for Perl library directories.
To install modules, you need to configure a local Perl library directory or
escalate your privileges.  CPAN can help you by bootstrapping the local::lib
module or by configuring itself to use 'sudo' (if available).  You may also
resolve this problem manually if you need to customize your setup.
What approach do you want?  (Choose 'local::lib', 'sudo' or 'manual')

It is essential that you  choose sudo for this question, not the default local::lib.

Initial NMIS Test. 

cd /usr/local/nmis9/
sudo ./bin/nmis-cli act=schedule job.type=selftest job.force=1

Output similar to:
[root@omk-vm9-centos7 nmis9]# ./bin/nmis-cli act=schedule job.type=selftest job.force=1
Job 602d1b6596c8066f7f538765 created for type selftest.

Validate Job:
**selftest was run and then we checked for active jobs with the "act=list-schedules" and it will report active items**
[root@omk-vm9-centos7 nmis9]# ./bin/nmis-cli act=list-schedules
Active Jobs:
Id                        When                      Status                                          What                Parameters
602d1b6596c8066f7f538765  Wed Feb 17 13:34:29 2021  In Progress since Wed Feb 17 13:34:33 2021      selftest            

Queued Jobs:
Id                        When                      Priority    What                Parameters
No queued jobs at this time.


Automatic Schedule:
Operation                     Frequency
Escalations                   1m30s
Metrics Computation           2m
Configuration Backup          1d
Old File Purging              1h
Database Cleanup              1d
Selftest                      15m
File Permission Test          2h
[root@omk-vm9-centos7 nmis9]# ./bin/nmis-cli act=list-schedules
No activities scheduled or in-progress.

Automatic Schedule:
Operation                     Frequency
Escalations                   1m30s
Metrics Computation           2m
Configuration Backup          1d
Old File Purging              1h
Database Cleanup              1d
Selftest                      15m
File Permission Test          2h
[root@omk-vm9-centos7 nmis9]# date
Wed Feb 17 13:35:19 UTC 2021

cd /usr/local/nmis9/
sudo ./bin/nmis-cli act=fixperms

Check the NMIS Dashboard. If the web server is running  but you can't access the GUI check your firewall; some Linux distributions do ship with a firewall enabled by default (e.g. RedHat 7) so a quick sudo iptables -n -L is recommended to verify the firewall status.

After authenting you should see the dashboard in all its glory, likely overlapped by the "Basic Setup" helper panel if this is an NMIS installation from scratch.

cd /usr/local/nmis9
mv /etc/snmp/snmpd.conf /etc/snmp/snmpd.conf.orig
mv /etc/snmp/snmptrapd.conf /etc/snmp/snmptrapd.conf.orig
cp conf-default/snmpd/snmpd.conf /etc/snmp/snmpd.conf
cp conf-default/snmpd/snmptrapd.conf /etc/snmp/snmptrapd.conf
cp conf-default/snmpd/snmptrapd.options /etc/sysconfig/snmptrapd # for CentOS/Red Hat only 

TRAPDRUN=yes

# as root
/sbin/chkconfig snmpd on
/sbin/chkconfig snmptrapd on

# as root
systemctl enable snmpd.service
systemctl enable snmptrapd.service

# as root
update-rc.d snmpd defaults
update-rc.d snmptrapd defaults
service snmpd start  
service snmptrapd start

sudo /usr/local/nmis9/bin/nmis-cli act=schedule job.type=update job.node=localhost

[root@omk-vm9-centos7 bin]# /usr/local/nmis9/bin/nmis-cli act=schedule job.type=update job.node=localhost
Job 602c2acf7c3f4515dbebdb35 created for node localhost (528a065e-2afe-4ca4-8cf7-7e032ce3e61e) and type update.

sudo /usr/local/nmis9/bin/nmis-cli act=schedule job.type=collect job.node=localhost

sh ./nmis<version>.run --keep --noexec

sh ./nmis<version>.run -- site=/opt/nmis

sh ./nmis<version>.run -- listdeps=true

sh ./nmis<version>.run -- -y
# recommended for safety: wrapped in screen with output logging on
screen -L sh ./nmis<version>.run -- -y