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Sonobuoy

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What Sonobuoy is

Sonobuoy is a free diagnostic tool for checking Kubernetes cluster state with non-destructive configuration tests. It tests whether a cluster conforms to official Kubernetes specifications and can generate diagnostics for troublesome workloads. Users can create plugins for custom tests and data collection. Its default plugins run Kubernetes end-to-end tests and gather systemd logs; community plugins cover areas including CIS Benchmarks, RBAC permissions, cluster inventory, and security visibility. Sonobuoy is cluster agnostic and officially supports the latest three minor Kubernetes versions. Version 0.20 and later supports Kubernetes 1.17 or later. It can run end-to-end tests with custom registries in air-gapped deployments. To run it, users need an active Kubernetes cluster and an admin kubeconfig; installation is available through binary releases or Homebrew on macOS. The open-source project offers community support through GitHub. Sonobuoy warns that its defaults are not secure by default and require explicit hardening. On Docker Desktop Kubernetes, some log and retrieval commands may fail, and the systemd-logs plugin may hang.

Who it suits

Sonobuoy suits people responsible for diagnosing Kubernetes clusters, checking conformance, or running custom configuration tests. It requires an active cluster and an admin kubeconfig.

What it does well

  • Runs non-destructive configuration tests.
  • Supports custom plugins for tests and data collection.
  • Can test in air-gapped deployments with custom registries.
  • Free and open source.

What to know first

  • Requires an active Kubernetes cluster and admin kubeconfig.
  • Defaults require explicit security hardening.
  • Some logging and retrieval operations may fail on Docker Desktop Kubernetes.

Limits

Only the most recent Sonobuoy version is supported for conformance tests on the latest Kubernetes version and two prior versions. Docker Desktop Kubernetes may fail with kubectl logs, sonobuoy logs, or sonobuoy retrieve, and the systemd-logs plugin may hang.

Getting started

  1. Open the Sonobuoy website
  2. Install a binary release or use Homebrew on macOS
  3. Prepare an active Kubernetes cluster
  4. Provide an administrator kubeconfig
  5. Run the built-in or selected plugins

Verdict

Sonobuoy provides Kubernetes diagnostics and conformance tests at no cost, with custom plugins and air-gapped support. Users should account for its cluster prerequisites and configure security hardening rather than relying on defaults.

Questions

Is Sonobuoy free?

Yes. Sonobuoy has a free plan and is released as open-source software.

Which Kubernetes versions does it support?

It officially supports the latest three minor Kubernetes versions. Sonobuoy 0.20 and later supports Kubernetes 1.17 or later.

What does Sonobuoy require to run?

You need an active Kubernetes cluster and an administrator kubeconfig.

Can Sonobuoy run in an air-gapped environment?

Yes. End-to-end testing can use custom registries in air-gapped deployments.

Which plugins are available?

Built-in plugins provide Kubernetes end-to-end tests and systemd logs. Listed community plugins include CIS Benchmarks, kube-hunter, Who-can, Cluster-Inventory, and Reliability Scanner.

How is Sonobuoy supported?

Community support is available through the Sonobuoy GitHub project, including issues, and a community Slack channel.

Facts from Sonobuoy's own pages

Air-gapped operation
It supports end-to-end testing with custom registries in air-gapped deployments. · sonobuoy.io, 30 Sept 2026
Air-gapped use
It supports end-to-end tests with custom registries in air-gapped deployments. · sonobuoy.io, 1 Oct 2026
Built-in plugins
The default plugins are Kubernetes end-to-end tests and systemd log gathering. · sonobuoy.io, 30 Sept 2026
CIS benchmarks
The CIS Benchmarks plugin uses kube-bench and runs checks on master and worker nodes. · sonobuoy.io, 1 Oct 2026
Cluster support
Sonobuoy runs on any Kubernetes cluster and officially supports the latest three Kubernetes minor versions. · sonobuoy.io, 1 Oct 2026
Community plugins
Listed plugins include CIS Benchmarks, Kube-hunter, Who-can, Cluster-Inventory, and Reliability Scanner. · sonobuoy.io, 30 Sept 2026
Community support
Community support is provided through the Sonobuoy GitHub project, including GitHub issues. · sonobuoy.io, 1 Oct 2026
Conformance testing
It tests whether a cluster conforms to official Kubernetes specifications. · sonobuoy.io, 1 Oct 2026
Custom testing
Users can create plugins to test custom configurations or use community plugins. · sonobuoy.io, 1 Oct 2026
Docker dependency
The sonobuoy images subcommand requires Docker to be installed. · sonobuoy.io, 1 Oct 2026
Docker Desktop limitation
The documentation reports that kubectl logs, sonobuoy logs, and sonobuoy retrieve may fail and the systemd-logs plugin may hang on Docker Desktop Kubernetes. · sonobuoy.io, 30 Sept 2026
End-to-end tests
The end-to-end plugin runs tests maintained by the upstream Kubernetes community. · sonobuoy.io, 1 Oct 2026
Host logs
The systemd-logs plugin gathers host log information by chrooting into the node filesystem and running journalctl. · sonobuoy.io, 1 Oct 2026
Installation
Installation is available through binary releases or Homebrew on macOS. · sonobuoy.io, 30 Sept 2026
Integrations
The documentation references AWS Quickstart, KinD, kubectl, Docker, and Docker Hub workflows. · sonobuoy.io, 30 Sept 2026
Kubernetes versions
Starting with version 0.20, Sonobuoy supports Kubernetes 1.17 or later. · sonobuoy.io, 30 Sept 2026
Open source
Sonobuoy is released as open source software. · sonobuoy.io, 1 Oct 2026
Prerequisites
Running Sonobuoy requires access to an up-and-running Kubernetes cluster and an admin kubeconfig. · sonobuoy.io, 1 Oct 2026
Purpose
Sonobuoy is a diagnostic tool for understanding Kubernetes cluster state by running configuration tests in an accessible, non-destructive way. · sonobuoy.io, 1 Oct 2026
RBAC reporting
The Who-can plugin reports which subjects have RBAC permissions to perform actions against cluster resources. · sonobuoy.io, 1 Oct 2026
Security defaults
The project states that Sonobuoy's default settings are not secure by default and require explicit hardening configuration. · github.com, 30 Sept 2026
Security support
Only the most recent Sonobuoy version is supported for conformance tests on the latest Kubernetes version and two prior versions. · github.com, 30 Sept 2026
Security visibility
The Kube-hunter plugin runs Aqua Security’s kube-hunter to increase visibility of security issues in Kubernetes environments. · sonobuoy.io, 1 Oct 2026
Support channel
The Sonobuoy community Slack channel has over 300 members. · sonobuoy.io, 1 Oct 2026

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