Self-host naemon-core
v1.5.2Network monitoring suite forked from Nagios
- Stars
- 173
- Requires
- Apache HTTP Server, Monitoring Plugins, Perl
What is naemon-core?
This network monitoring application written in C watches hosts and services, sending alerts when problems appear and when they clear. It originated as a fork of Nagios 4.0.2 with the goal of being a drop-in replacement that adds bug fixes, new capabilities, and performance improvements. The suite bundles the monitoring engine, Livestatus (a query interface for the core), and Thruk (a modern web UI that replaces the old Nagios CGIs). Core capabilities include checking network services like SMTP, HTTP, and PING, tracking host metrics such as CPU load and disk space, a plugin system fully compatible with Nagios plugins, parallel execution of service checks, notifications delivered by email or custom methods, event handlers for automated remediation, support for distributed and redundant monitoring setups, flap detection, and performance data collection. Users can install it via binary packages from the openSUSE Build Service for Ubuntu, Debian, Red Hat, CentOS, SLES, and Fedora, or compile from source. The web interface uses basic authentication via htpasswd. The project is licensed under GPL-2.0 and maintained by a community team.
Should you self-host naemon-core?
naemon-core scores 49/100 on selfhost.directory (how scoring works) and ranks #11 of 19 in Infrastructure Monitoring. It has 173 GitHub stars.
It shipped 3 stable releases in the past year. The latest, v1.5.2, came out on 18 May 2026. New versions land roughly every 2 months.
Setup is advanced: plan for several services and some ongoing maintenance. It is GPL-2.0-licensed and written mostly in C.
Its closest alternative on selfhost.directory is NetAlertX (70/100, 7 337 stars). It scores higher overall, so compare the two before you pick. See naemon-core vs NetAlertX side by side.
Features
- Adaptive monitoring
- Contact notifications
- Distributed Monitoring
- Event handlers
- Flap detection
- Host hierarchy with parent hosts
- Host resource monitoring
- Nagios-compatible plugin system
- Network service monitoring
- Parallelized service checks
- Performance data processing
- Scheduled downtime
naemon-core README
FAQ
Help Extending The Documentation
Documentation contributions are welcome; small changes can be made via GitHub's online editor, larger changes should be tested locally with VitePress.
Run Naemon With GDB
For error tracing, Naemon can be started with GDB using LD_PRELOAD for libpthread.so.0 and the naemon-dbg package for debugging symbols.
What Are The Differences To Nagios?
Many open Nagios 4 issues have been fixed in Naemon, and the old Nagios CGIs were replaced with the Thruk GUI.
How Can I Help?
Help is appreciated in many ways; details can be found on the community page.
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