# Icinga — Modern Open Source Infrastructure Monitoring

> A scalable monitoring system that checks availability and performance of network resources, notifying on outages and generating metrics.

## Install

Save as a script file and run:

# Icinga — Modern Open Source Infrastructure Monitoring

## Quick Use
```bash
# Install on Ubuntu
apt install icinga2 icingadb icingadb-redis icingaweb2
# Enable API and basic features
icinga2 feature enable api
icinga2 api setup
systemctl restart icinga2
# Access web UI at https://localhost/icingaweb2
```

## Introduction
Icinga is a monitoring system forked from Nagios that addresses scalability and modern infrastructure needs. It monitors network resources, sends alerts on failures, and generates performance data — with a distributed architecture that scales from a handful of servers to thousands of endpoints across multiple data centers.

## What Icinga Does
- Monitors hosts and services via agent-based or agentless checks
- Sends notifications via email, SMS, PagerDuty, and custom scripts
- Collects and stores performance metrics for trending and capacity planning
- Supports distributed monitoring across multiple zones and satellites
- Provides a modern web dashboard with drill-down capabilities

## Architecture Overview
Icinga 2 uses a C++ core with a domain-specific configuration language. The cluster architecture supports zones (logical groupings), endpoints (Icinga instances), and satellites (distributed check execution). IcingaDB replaces the legacy IDO module, storing state in Redis for real-time access and syncing to a relational database for historical data. Icinga Web 2 provides the PHP-based user interface.

## Self-Hosting & Configuration
- Install core via official repositories (Debian, RHEL, SUSE, Windows)
- Define hosts and services in DSL configuration files or Director GUI
- Deploy agents on monitored hosts for local check execution
- Configure notification rules with escalation chains and time periods
- Integrate with Grafana for advanced metric visualization

## Key Features
- Distributed monitoring with zone-based cluster topology
- Configuration DSL with apply rules, templates, and runtime macros
- REST API for automation, orchestration, and custom integrations
- Director module for web-based configuration management
- Backwards-compatible with Nagios check plugins ecosystem

## Comparison with Similar Tools
- **Nagios** — Original project Icinga forked from; Icinga has better clustering and modern API
- **Zabbix** — More built-in auto-discovery; Icinga offers stronger configuration DSL
- **Prometheus** — Pull-based metrics focus; Icinga is traditional check-based with active alerting
- **Sensu** — Agent-based with modern API; Icinga has broader legacy plugin compatibility

## FAQ
**Q: Is Icinga compatible with Nagios plugins?**
A: Yes. Icinga executes standard Nagios check plugins without modification, giving access to thousands of community checks.

**Q: How does Icinga handle distributed monitoring?**
A: Using zones and satellites. Parent zones delegate check execution to child zones, with configuration sync and state replication between endpoints.

**Q: Can I monitor Kubernetes with Icinga?**
A: Yes. Use the Kubernetes check plugins or integrate with the Icinga module for Kubernetes to monitor pods, deployments, and cluster health.

**Q: What is the difference between Icinga 2 and Icinga Web 2?**
A: Icinga 2 is the monitoring core that executes checks and sends alerts. Icinga Web 2 is the separate web frontend for visualization and configuration.

## Sources
- https://github.com/Icinga/icinga2
- https://icinga.com/docs/icinga-2/latest/

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Source: https://tokrepo.com/en/workflows/asset-621c5ec8
Author: Script Depot