Checkmk: Open Source Monitoring & Observability

What is Checkmk?

What it is

Checkmk is a comprehensive IT monitoring system for infrastructure and application monitoring across physical, virtual, containerized, and cloud environments. It is an open-source Python project released under the GNU GPL v2, and it lives in the infrastructure monitoring and observability ecosystem. The project provides a central monitoring engine, a web-based interface, and support for many official and community-maintained plugins.

The problem it solves is fragmented monitoring. Operators often need to watch servers, applications, cloud resources, and containers at the same time, but they may use separate tools for each area. Checkmk addresses this by supporting agent-based and agentless monitoring, offering editions for different scale and automation needs, and providing packages, containers, appliances, and a hosted option.

Key capabilities

Checkmk Community includes the core monitoring engine, a web-based UI, agent-based and agentless monitoring, and support for hundreds of official and community-maintained plugins.
Pro adds distributed monitoring, built-in dashboards, automated agent management, and support for enterprise integrations such as LDAP and REST APIs.
Ultimate adds monitoring for dynamic environments such as Kubernetes, AWS, Azure, and GCP, including application metrics collection via OpenTelemetry.
Ultimate also supports push agents and auto-registration of hosts, which helps operators manage changing cloud workloads.
Multi-Tenancy adds centralized monitoring across multiple customer environments, isolated access controls, and managed service provider reporting.
Checkmk Cloud provides a hosted version with automatic updates, backups, and onboarding without infrastructure overhead.

Who uses it and how

Small or basic environments can use Checkmk Community for core monitoring, a web UI, and plugin-based checks without paid licensing.
Cloud-native teams can use Checkmk Ultimate to monitor Kubernetes, AWS, Azure, and GCP, and to collect application metrics through OpenTelemetry.
Managed service providers can use Checkmk Ultimate with Multi-Tenancy to monitor several customer environments from one place while keeping access isolated.

Getting started

Checkmk can be installed on Linux through DEB and RPM packages for RedHat-derived distributions, Ubuntu, and SUSE Linux Enterprise Server, and all editions can also run as Docker containers. Pro, Ultimate, and Ultimate with Multi-Tenancy are additionally available as virtual or physical appliances, while Checkmk Cloud is the hosted option.

When to use it — and when not to

Checkmk is a good fit when one tool must cover infrastructure, applications, cloud resources, and containerized workloads, especially if the team can select the right edition for its scale. Checkmk Community is suitable for smaller environments with basic automation, dashboarding, and support needs, but distributed monitoring, enterprise integrations, advanced cloud-native features, and multi-tenancy belong to higher editions. Self-hosted deployments require the operator to manage the chosen package, container, or appliance, while Checkmk Cloud features automatic updates, backups, and onboarding with no infrastructure overhead.

project readme (upstream, from github) — read inline

Checkmk - Your complete IT monitoring solution

Checkmk is a comprehensive IT monitoring system designed for scalability, flexibility, and low resource consumption. It supports infrastructure and application monitoring across physical, virtual, containerized, and cloud environments.

Checkmk is available in several editions, each suited to different operational needs. Please visit our website for more details, documentation, new releases, discussion forums, and more.

Checkmk Community

Checkmk Community is completely free and open-source (licensed under the GNU GPL v2). It includes the core Checkmk monitoring engine, a web-based UI, agent-based and agentless monitoring, and support for hundreds of official and community-maintained plugins.

This edition is ideal for smaller environments with basic requirements in terms of automation, dashboarding, and support. Download it in various formats here.

Checkmk Pro

A commercial edition that extends Checkmk Community with advanced features for performance, automation, and usability. These include distributed monitoring, built-in dashboards, automated agent management, support for enterprise integrations (e.g. LDAP, REST APIs), and more. Professional support is included. A demo version can be freely downloaded for evaluation purposes.

Checkmk Ultimate

Tailored for modern cloud-native infrastructures, Checkmk Ultimate includes all Pro features, plus enhanced capabilities for monitoring dynamic, ephemeral environments such as Kubernetes, AWS, Azure, and GCP. It supports application metrics collection via OpenTelemetry, and features push agents and auto-registration of hosts. Download the free trial.

Checkmk Cloud

For teams that prefer not to deploy Checkmk themselves, Checkmk Cloud is the SaaS version of Checkmk. It features automatic updates, backups, and easy onboarding, with no infrastructure overhead for the end user. Try it for free here.

Checkmk Ultimate with Multi-Tenancy

Designed for managed service providers, Checkmk Ultimate with Multi-Tenancy builds on the Checkmk Ultimate feature set and adds multitenancy support, centralized monitoring across multiple customer environments, isolated access controls, and MSP-specific reporting. A free trial is available or you can directly request a quote.

Installation

Checkmk can be installed on Linux via DEB and RPM packages. We support RedHat (and derived distributions like CentOS, AlmaLinux, Rocky Linux, Oracle Linux and more), Ubuntu, and SUSE Linux Enterprise Server with official packages. Generally LTS/stable versions of these distributions are supported. Direct instructions on the installation of Checkmk can be found on these distribution-specific documentation pages:

All Checkmk editions can be also installed as Docker containers. Full instructions here.

Checkmk Pro, Ultimate and Ultimate with Multi-Tenancy are also available as virtual or physical appliances. All packages, images, and containers can be found on our downloads page.

Getting started

Please have a look at the beginners guide on how to get started with Checkmk.

Want to contribute?

Nice! Before contributing please check out our contribution guidelines.

Building your own packages

It is highly recommended to use the prebuilt Checkmk packages we provide. But if you really want to build your own packages, you either need to download the source packages from our website or check out the Git repository.

We're building the Checkmk packages within specific docker images for the different distros. Please find the Dockerfiles under buildscripts/infrastructure/build-nodes/ in order to get an idea what's needed to build it locally. However, keep in mind that those Dockerfiles are heavily relying on our infrastructure and won't build from scratch on your machine.

If you have the dependencies in place, you can either create RPM or DEB packages, depending on your Linux distribution.

To build an RPM:

make rpm

To create a DEB package:

DEBFULLNAME="Mr. Buildmaster" DEBEMAIL="[email protected]" make deb

Don't forget to insert your name and mail address. As a result you should find packages of the form check-mk-[edition]-[version].[deb|rpm] in your current directory.

Frequently asked questions

Is Checkmk free to use?

Checkmk is open source under the GPL-2.0 licence. There is no licence fee and no seat count — you can self-host it or, where the project offers one, pay a vendor for a managed version instead.

What does Checkmk do?

Complete IT infrastructure monitoring made simple

What is Checkmk written in?

Checkmk is primarily written in Python. Its source is publicly available at https://github.com/checkmk/checkmk, and it has 2,368 GitHub stars.