If desired, you can disable nagios-api by editing the root cronjob which enables the API at NEMS boot.
Default Passwords (And How To Change Them)
Web access password is created during initialization. To initialize NEMS 1.2, use the command: sudo nems-init The easiest way to change this password after NEMS is already initialized, simple re-run the initialization script. If you wish to leave your pi user password as is, just enter the existing password again during init, and you can press CTRL-C when prompted to abort expanding the filesystem (as it’s unnecessary to do it again).
If you’re more adventurous and prefer to do it yourself, you can instead add an htpasswd to /var/www/htpasswd and then change the username in both /etc/nagios3/global/contactgroups.cfg and /etc/nagios3/global/contacts.cfg to give the new user access to Nagios Core. But again, all this stuff is automated with sudo nems-init so you can save yourself some trouble by just doing that.
Login using the default password, and immediately choose User menu→Change Password
Best leave this as is since changing it would break a lot of stuff. Just never open up your MySQL port to the world, that’s all.
Also important to note that if you manually add any databases or tables, you will lose them if you run a nems-init or a NEMS-Migrator restore. Best leave MySQL alone, and put in a feature request in the comments if you need to add something.
Quick way to test if WMIC is working from within a NEMS SSH seession:
Where WINDOWSIP, WINDOWSUSER and WINDOWSPASS are the actual IP of the Windows computer, and the administrator user/password for that computer.
Run it twice, and then if it’s successful you should see something like this:
OK(Sample Period6sec)-Average CPU Utilisation1.83%|'Avg CPU Utilisation'=1.83%;20;90;
WMIC takes up a fair bit of space on the Pi’s SD card, which resulted in NEMS 1.2 minimum system requirement being 8 GB.
This is the historical changelog. For the latest version of NEMS please visit baldnerd.com/nems
Version 1.1 – November 13, 2016
– NagVis upgraded to 1.8.5. (1.9 is still beta).
– Check_MK livestatus upgraded to 1.2.8p13.
– Added Check_MK Multisite 1.2.8p13.
– Added PNP4Nagios 0.6.16-2.
– Added a few sample configurations to NConf to help users figure out the initial setup and/or to use as templates. Included samples are: test if an external web site is up via ping, monitor a Linux server, monitor a Windows server.
– Created NEMS Migrator. New feature allows backing up and restoring your NEMS configuration, making migration or recovery a breeze. Upgrade from NEMS 1.0.
– Added sendemail 1.56-5 and setup email config in /etc/nagios3/resource.cfg (you’ll need to add your SMTP info as per the instructions above).
– Added git, htop.
– raspi-config upgraded to 20161108.
– Linux kernel upgraded to 4.4.26-v7.
– Apache2 upgraded to 2.4.10-10+deb8u7.
– OpenSSL upgraded to 1.0.1t-1+deb8u5.
– MySQL upgraded to 5.5.52-0+deb8u1.
– Exim4 upgraded to 4.84.2-2+deb8u1.
– PHP upgraded to 5.6.27-0+deb8u1.
– PHPMyAdmin upgraded to 4.2.12-2+deb8u2.
– Python upgraded to 2.7.9-2+deb8u1.
– Network and Bluetooth firmwares upgraded.
– Various system components upgraded.
– Reduced the amount of memory dedicated to Raspberry Pi graphics adapter.
Version 1.0 – May 8, 2016 (Discontinued November 13, 2016, Downloaded 409 Times)
– Initial release. Built and tested on Raspberry Pi 3. Based on Raspbian Jessie. Inspired by NagiosPi, which in April 2016 was still running on the old Raspbian Wheezy. I started this new distro since NagiosPi seems to be out of date, and I want to have an easy drop-in Nagios img for the Raspberry Pi. Figured I’d share it with the world while I’m at it since there are probably others (possibly less tech savvy) who might want the same thing. I decided to leave most of the settings the same as NagiosPi (eg., usernames, passwords) so those coming from that distro can seamlessly transition, or so if NagiosPi wants to use our build to bring things up to date, they may do so with minimal effort.
– This initial build is using default repositories in a lot of cases and is meant to be rock-solid, not bleeding edge (eg., Nagios 3.5.1 instead of Nagios 4.1.1.
– Using the rpi-4.4.y Linux kernel tree (Currently 4.4.7-v7+ #876 SMP), firmware updated to 1e84c2891c1853a3628aed59c06de0315d13c4f1. Use rpi-update to check for upgrades, if needed.
– Includes rpi-update tool – an easier way to update the firmware on the Raspberry Pi – See https://github.com/Hexxeh/rpi-update
– On-board Bluetooth disabled due to potential stability issues. Use rpi-update to check for kernel updates and see if it is fixed, and then edit /boot/config.txt to re-enable. Until they fix it, use USB Bluetooth dongle if needed.
– Installed and configured: mysql-server mysql-client phpmyadmin apache2 nagios3 nagios-nrpe-plugin
– To keep things consistent for those coming from NagiosPi, I have used the same passwords. MySQL is: User: root Pass: nagiosadmin
– Installed w3m web browser to allow local testing in terminal: w3m localhost/phpmyadmin
– Manually installed NConf 1.3.0-0 “Final”, an Enterprise Nagios configuration tool. This tool was broken on NagiosPi’s instructions due to a missing symlink at /var/www/nconf, so I fixed that in my version. Access NConf via the “Configure Nagios” link on the main menu.
– Includes NagVis 1.7 – want to do 1.9 but not until out of beta.
– Built and integrated the first version of our menu system, which includes the first version of a custom Nagios skin to begin integrating a more modern interface. Menu accessible at http://nems/ (or http://IPADDRESS if that doesn’t work for you)
– Added a nice little MOTD.
– Added a simple cronjob to check our web site for the currently available version and warn you if yours is out of date.
One of the worst things that can happen to your NEMS deployment is having your SD card fail. So keeping a current backup of your NEMS configuration is a smart idea.
Your NEMS Migrator snapshots are always accessible at http://NEMSIP/backup/ and will automatically generate and send a backup.nems file, which contains all the NEMS configuration settings, logs, data, etc. to allow an easy recovery by restoring to a new NEMS deployment.
Knowing this, it’s easy to add a NEMS backup to your daily backup script.
From your Linux server (where your backups run), simply add this to your backup task:
… where /backup/backup.nems is where you want it to output the download, NEMSIP is the actual internal IP address of your NEMS server and YOURUSER and YOURPASSWORD are those you set during nems-init. From there, I recommend you have your backup script run an rdiff-backup of your /backup folder (in this example) to allow for versioning.
Choose “Complete installation” and if asked, choose to save config to ini file.
Under “Allowed Hosts” it should read 127.0.0.1,NEMSIP (where NEMSIP is the IP address of your NEMS server)
Clear the Password field for ease of deployment. NEMS sample scripts are setup to use NRPE without a password because I’m making the assumption that this is being deployed in a trusted LAN. If you do not blank the password here, you will have to edit all the scripts before NEMS will be able to communicate with this computer.
Enable all modules and change the NRPE mode to Legacy. NEMS uses Nagios 3.5.1 at present, and I suppose that’s technically “Legacy”. 🙂
Screen should look a little something like this:
Add your Windows host to NEMS. If you are using NEMS 1.1+ you can use the template “ourwinserver” in nconf. Just change the hostname and the IP address.
Please note: If you have a software firewall running on your Windows machine, setup an exception for your NEMS server IP to gain access through ports 5666 and 12489.
Thanks for being an early-adopter! Whether you’re coming from NEMS 1.0 or its predecessor, nagiospi, I want to make it as easy as possible for you to get the latest and greatest, without having to reconfigure everything. It’s been exciting to see the NEMS project really catching on, and I endeavor to make it the best it can be. Your suggestions along the way have helped me focus on some great features for as NEMS continues to evolve.
NEMS 1.1+ has a nifty backup and export tool called NEMS Migrator. While it comes pre-packaged in 1.1+, I designed it specifically to run on legacy builds as well (NEMS 1.0 or nagiospi), giving you the opportunity to export your old configuration, deploy the latest version of NEMS, and then restore the configuration to NEMS. Easy peasy!
Here’s what you need to do:
Note: These instructions are for NEMS 1.0 or nagiospi only. Do not do this on NEMS 1.1+ as the tool is already built-in.
SSH into your NEMS/nagiospi server.
Become root: sudo su
Update repository data. Type: apt-get update
Install Git. Type: apt-get install git
Install NEMS-Migrator in /tmp. Type: cd /tmp && git clone https://github.com/Cat5TV/nems-migrator
Create the backup config on your NEMS/nagiospi system. Type:
If on NEMS 1.0: cd /tmp/nems-migrator && ./backup.sh
If on nagiospi: cd /tmp/nems-migrator && ./nagiospi2nems.sh
Download the backup to your computer by opening it in your web browser. In your favorite web browser, simply add /backup/ to the end of your NEMS/nagiospi server address. Eg., http://10.0.0.5/backup/
Now that you have your backup.nems file, follow the instructions here to restore your configuration to a new version of NEMS.
NEMS Migrator is also helpful when upgrading from previous versions of NEMS, saving you having to reconfigure your NEMS deployment just to get the latest features.
Important Note I am a firm believer in redundancy, and protecting your data. What I’d like you to do is, export your migration file, then install NEMS on a new MicroSD card. Then boot from that and restore your NEMS Migrator backup. Once you’ve confirmed everything worked well, you can deprecate the old one safely. However, if something went wrong, you can contact me to fix it for you, and continue running from the old SD card in the interim.
How to Restore a NEMS Migrator Backup
Requires NEMS 1.2+
Place your backup.nems file on a USB flash drive. You can access this directly from your web browser at http://NEMSIP/backup/ where NEMSIP is the IP address of the NEMS server you wish to backup.
Deploy the version of NEMS you wish to restore the backup to. Please heed my Important Note above.
Boot the new NEMS deployment and mount the USB flash drive.
Determine the location of backup.nems in relationship to your mountpoint. For example, if you mounted the USB flash drive on /mnt/flash you may determine the location to be /mnt/flash/backup.nems
Armed with that information, run the following command (use the full path to your backup.nems file):
Follow the prompts on screen to restore your configuration to the new NEMS deployment. If it fails for any reason, you can safely shut down and replace the SD card with your original deployment.
If you have any problems (or praise) please comment below.
The Nagios Remote Plugin Executor (NRPE) allows your Nagios Enterprise Monitoring Server to communicate with the Linux machines on your server to determine things like free disk space, CPU load, and detect possible issues that a simple ping can’t determine.
There are countless instructions online to download tar.gz files and install manually, or use a PPA to install via apt-get, but you’ll be surprised to note the needed packages are in fact already in your Debian (and by proxy, Ubuntu) repositories.
To install the needed NRPE client on Debian / Ubuntu / other Debian-based Linux operating systems:
apt-get install nagios-nrpe-server nagios-plugins
Don’t forget that you need to be root (Debian) or use sudo (Ubuntu).
Next, we just have to tell NRPE that it’s allowed to communicate with our Nagios server. On the client system, open the file /etc/nagios/nrpe.cfg
Find the line that reads: allowed_hosts=127.0.0.1
Now there are a few ways we can allow our server. First (and most obvious) is to add its IP address like this:
Where 192.168.0.5 is our Nagios/NEMS server.
Alternatively we can tell NRPE that it’s allowed to communicate with any local system:
Now, save the file and restart NRPE as follows:
service nagios-nrpe-server restart
And there we have it! Your Nagios/NEMS server should now be able to see your Linux machine.
NEMS – Nagios Enterprise Monitoring Server for Raspberry Pi
NEMS is a modern pre-configured, customized and ready-to-deploy Nagios Core image designed to run on the Raspberry Pi 3 micro computer. At its core it is a lightweight Debian Stretch deployment optimized for performance, reliability and ease of use.
NEMS is free to download, deploy, and use. Its development however is supported by its community of users. Please consider contributing if you can.
Nagios® Core™ is an Open Source system and network monitoring application. It watches hosts and services that you specify, alerting you when things go bad and when they get better.
Some of the many features of Nagios Core include:
Monitoring of network services (SMTP, POP3, HTTP, NNTP, PING, etc.)
Monitoring of host resources (processor load, disk usage, etc.)
Simple plugin design that allows users to easily develop their own service checks
Parallelized service checks
Ability to define network host hierarchy using “parent” hosts, allowing detection of and distinction between hosts that are down and those that are unreachable
Contact notifications when service or host problems occur and get resolved (via email, pager, or user-defined method)
Ability to define event handlers to be run during service or host events for proactive problem resolution
Automatic log file rotation
Support for implementing redundant monitoring hosts
Optional web interface for viewing current network status, notification and problem history, log file, etc.
Nagios doesn’t need a big fancy supercomputer to offer exceptional enterprise monitoring of network assets and resources, so our temptation is to re-purpose older servers to perform this reasonably lightweight task.
If you ask me, that’s not only overkill, but the attempt to save money by reusing older hardware will actually cost more due to higher electricity usage vs. a tiny Raspberry Pi 3 Microcomputer… which ironically may in fact have more modern system specifications than that old beast of a server you’ve been using.
It can be a wee bit daunting to setup a Raspberry Pi Nagios server from scratch, and there were no projects I found which were actively maintained at a level adequate for professional use. So I decided to start a new project–called NEMS: Nagios Enterprise Monitoring Server (for Raspberry Pi).
This project uses freely available applications such as Debian Linux, Nagios Core and a variety of other goodies, and I too release a fully ready-to-use image for you to use within yours or your customer’s network environments.
The goal with NEMS is to provide a free, full-featured, up to date drop in Nagios Enterprise Monitoring Server for Raspberry Pi 3. It has all the bells and whistles while being optimized for solid stability and fast performance.
The original NEMS release was based (with big thanks to Ryan Siegel) on NagiosPi, with many of the settings reflective of the NagiosPi Wheezy distro (which is now obsolete).
Here is what Ryan Siegel (the creator of NagiosPi) has to say about NEMS: “I’d love to upgrade NagiosPi, but i don’t have ability to make a GUI that can beat that of NEMS. I strongly feel that it has always been a necessary addition to NagiosPi and NEMS was able to deliver what is essentially an updated and improved version of NagiosPi. No reason not to start using NEMS for the time being. Nice work Robbie!” [source]
NEMS has since become a popular drop-in Nagios distro for Raspberry Pi, with a major release twice per year.
Login to NEMS console by either connecting a monitor and keyboard, or using ssh (Username: pi / Password: raspberry)
Type: sudo nems-init
After rebooting, reconnect and restore your backup.nems NEMS-Migrator file if you have one.
Edit /etc/nagios3/resource.cfg and add your SMTP information.
Login to NagVis and change the password (default is: admin/admin)
Reboot your Pi and enjoy NEMS when it comes online (see below for further details).
Buy The Needed Hardware
Raspberry Pi 3 are very affordable, and using our Micro SD image, you simply buy the device, “burn” the image to the Micro SD card, and boot it up.
Here’s our link to buy the device you’ll need, complete with the Micro SD card, a power adapter, a good solid case, and more: shop.category5.tv
Please buy it through that link, or let me know if you need a customized link to a different model. We get a small percentage of the sale, and it helps to make it possible to offer this as a free download.
NEMS 1.2.1 Changelog
NEMS 1.2 was released May 6, 2017. NEMS 1.2.1 was released May 22, 2017 to fix bugs with the migrator and improve the overall release following significant user feedback.
Here is a list of the changes I recorded during development.
– NEMS now requires you to run nems-init when you first deploy. This tool takes care of some of those “first boot” prerequisites like setting passwords and expanding your filesystem.
– Underlying OS upgraded to Raspbian Stretch.
– Kernel upgraded to 4.9.28.
– PHP upgraded to 7.0.19.
– Reworking of nConf to make compatible with modern software (ie. PHP7.0, mySQLi).
– Maintenance and info scripts moved to /home/pi/nems-scripts.
– NEMS MOTD upon login now shows local IP address. Also improved how it determines some of the info (see info.sh in nems-scripts) and fixes a few bugs. Also set it up to rollover to wlan0 if no response on eth0, in case the user is on wifi.
– Temporary files and Monitorix image cache moved to RAM.
– Added RPi-Monitor as per Hesh’s comment. Reworked the Memory and CPU Frequency modules to correct the accuracy.
– Added nagios-api (JSON on Port 8090) as per Timothy Seibert’s request. [License]
– Added Webmin as per Hesh’s comment. Login as pi user with the password you created when initializing NEMS with the nems-init program.
– Added support for agentless Windows checks using WMI (big thanks to Ryan Siegel).
– Changed Apache log rotation to weekly (was previously daily).
– Upgraded nagvis to 1.9b16.
– Fixed sendemail paths in nConf to ease out-of-the-box email notifications (as they should just work now). Thanks so much to Jim for pointing this typo out!
– Enabled CPU governing (package cpufrequtils). On NEMS 1.0-1.1, NEMS was locked to 600MHz, but now it will automatically go up to 1200 MHz as needed.
– force resolver to generate new DNS resolv.conf at first boot (to ensure the detected DNS servers will be used rather than our development DNS servers which may not work for you).
– NEMS Migrator upgraded to allow direct migration from nagiospi to NEMS.
– Added Monitorix 3.9.0.
– Removed MySQL, replaced with MariaDB 10.1.22.
– Improve quality of Monitorix graphs used on NEMS Dashboard slideshow.
– Minor improvements to Monitorix page based on priority of service and image quality.
– Removed some old (obsolete) kernel modules, InnoDB logs and other bloat to reduce size of stock image.
– Added /var/www/nconf/temp to tmpfs. This way if someone breaks their nCONF (eg., pressing “Back” while generating config) they can just reboot to fix it 😀
– nems-init and nems-migrator restore significantly reworked to correct initialization bugs from NEMS 1.2. Now, both initialization of a new NEMS deployment and an import from an old one should work without a hitch.
– nConf and NEMS-Migrator backups now require your password (as set with nems-init).
– NEMS-Migrator no longer replaces the MySQL database with backup. Instead, it now clears the database completely, reconciles your backup with the current set of available commands and services and then imports everything together into the fresh database and activates the hosts. This way, if you restore your NEMS 1.1 settings to NEMS 1.2.1, you don’t miss out on all the WMIC features (which your 1.1 backup would overwrite), for example.
– Documentation updated to reflect changes in commands and versioning.
– I built a quick but lovely interface for Monitorix to make it mobile responsive and a little more dynamic in its functionality.
– Distribution now available via BitTorrent (thanks to our partnership with The Category5 TV Network
– number of online users count on MOTD fixed.
– undefined constant in apache error log every 5 minutes leading to a bloated error log.
– added missing icons in check_mk.
– NEMS Migrator mail settings fixed when importing backup.nems from NEMS 1.0/nagiospi.
– Fixed MySQL Initialization Bug – was causing NEMS to lose configuration and no longer work.
– Wifi (wlan0) restored after it broken in 1.2 (due to Debian Stretch upgrade and incompatible firmwares for the Pi).
– Fixed nems-init user creation. In NEMS 1.2 it was not adding the new user to the “admin” group correctly in NEMS nCONF, so upon config generation, user would lose access to Nagios Core and other features requiring admin user.
– many miscellaneous bug fixes.
Configuring Your NEMS Server:
Browse to: http://NEMS.local/nconf (or http://IPADDRESS/nconf)
Make changes to the config as needed for your environment (eg., add a host, service, edit a setting)
I’ve added a few sample configurations in there (v1.1+) to help you get started.
Click: “Generate Nagios Config”
If there are no errors, you will have the option to Deploy the new Nagios Config.
Using Your NEMS Server:
Browse to: http://NEMS.local (or http://IPADDRESS)
The navigation should be fairly straightforward. To add hosts or configure your environment, use the built in nConf feature. To access reports, choose one of the reporting options under Reporting. To access info specific to your Pi (eg., memory usage) you’ll find those under System.
When you initialize NEMS, you will provide a password for the NEMS web interfaces. This username/password will be what you use to access most NEMS features (eg., nCONF, Nagios Core, Check_MK) however, Nagvis still uses admin:admin. Please be sure to change that when you first login to Nagvis. To login to Webmin, use the username pi and the password you entered for the pi user during nems-init.
PNP4Nagios is installed, but not configured. You may encounter errors, which will be addressed in a future release.
If you encounter an issue, please report it in the comments below so I can work on a fix (or please post your fix to help others and possibly to have it integrated into the next build).
This list details features which are planned for future releases of NEMS. NEMS is released on a 6 month schedule, with a major release every May and November. Thanks to the NEMS Migrator, upgrading is a cinch.
– Further improve the mobile responsive layout for tablets and smartphones (It’s really rudimentary at the moment due to the nature of Nagios’ interface… frames? C’mon now.)
– Upgrade Nagios to Nagios Core 4. (?) – Unlikely since most of the cool things about NEMS rely on Nagios Core 3.5.1 … at least for now.
– Further streamline the implementation of Check_MK. Deploy check-mk-server.
– Expand the documentation to include setting up SMTP and mail alerts, including a new video demonstration on Category5 Technology TV.
– Create an OVA of NEMS for deployment on existing virtual infrastructures (just for the challenge/fun of it).
– Build a graphical interface for nems-init.
– Build a graphical interface for NEMS-Migrator’s “Restore” feature.
– I’m open to suggestions! Please post your comments at http://baldnerd.com/nems
Things I Will Not Do:
This is a list of features I will not implement.
– Raspberry Pi Zero, 1 & 2 support. Buy a Raspberry Pi 3. The higher performance of a Pi 3 is a major asset for a project like NEMS, so I will not be focusing any of my efforts on supporting legacy hardware.
– GUI/Desktop. NEMS is a Linux server. If you require a GUI/Desktop Environment, you’re doing it wrong. I have built a very nice, easy to use web interface, and have worked hard to provide good documentation to ease the complication of configuration for novice users. NEMS itself should not even have a screen connected to it. Just power and Ethernet. Everything happens either through your browser, or for advanced users, an SSH connection.
Who Creates NEMS: Robbie Ferguson is the host of Category5 Technology TV. He’s the kind of guy who when he figures stuff out, he likes to share it with others. That’s part of what makes his show so popular, but also what makes NEMS possible.
Support What We Do:
This project is a part of something much bigger than itself, and we’re all volunteers. Please see our Patreon page for information about our network.
– Please support us by simply purchasing your Raspberry Pi at https://cat5.tv/pi
– We have some support links on the NEMS menu, such as buying from Amazon using our partner link. Please use these every time you use those stores. A small percentage of your purchase will go toward our projects.
– Your donations are VERY MUCH appreciated – https://donate.category5.tv – Please consider how many hours (and hours) of work this project has saved you, and how much you’ll save on hardware and even electrical costs as you consider contributing
– Our network also has a Patreon page – Please consider becoming a patron – https://patreon.com/Category5