Fairwinds Polaris

Overview

Fairwinds Polaris is an open-source policy engine for Kubernetes resource configuration. It is a strong fit for teams that want to check manifests and cluster workloads against configuration practices without adding a paid policy-engine plan. Its range of run modes is useful, but admission validation requires a valid TLS certificate.

Key features

Polaris ships with more than 30 built-in policies and lets teams define their own using JSON Schema. Checks cover security settings such as privilege escalation, root execution, read-only root filesystems, and host IPC or PID use; reliability practices such as readiness and liveness probes; and CPU and memory requests and limits. It also flags unspecified or latest image tags and checks image pull policy. This breadth makes it useful for catching both risky defaults and routine deployment gaps, though teams with requirements beyond those checks will need to write custom policies.

Teams can run Polaris as a dashboard, admission controller, or command-line tool. The CLI checks local YAML files in CI/CD, while the dashboard can audit local files or connect to a cluster using KUBECONFIG credentials. The dashboard can be installed in a Kubernetes cluster with kubectl or Helm. These options let teams place checks before deployment, in the cluster, or both.

The validating webhook rejects workloads that trigger danger-level checks; warning-level findings pass and appear in the dashboard or webhook logs. That distinction allows enforcement of high-risk policies without blocking every warning. The mutating webhook and CLI can automatically remediate supported issues, including missing limits and probes and some unsafe security settings. Remediation is limited to supported cases, so it does not replace review of every finding.

Polaris findings can also be included in Fairwinds Insights, which records results across clusters with remediation guidance. Teams seeking multi-cluster history or Slack, Datadog, and Jira integrations should consider that service alongside Polaris. Fairwinds says it is SOC 2 Type II compliant. Its container images are signed and image tags are immutable; documentation recommends using full version tags or pinning by digest.

Pricing

Polaris is free and open source, with no paid tier or seat and quota limits specified in its plan. The Polaris (Open Source) plan costs nothing and is aimed at small teams. That makes it accessible for teams evaluating Kubernetes policy checks, while teams needing the multi-cluster history and integrations described for Fairwinds Insights may need to consider that product separately.

Platforms

Polaris supports Linux, macOS, Windows, web, and self-hosted use. Its Kubernetes focus is central: the dashboard can run in a cluster or locally with KUBECONFIG credentials, and the CLI can be integrated into CI/CD checks for local YAML.

Who it's for

Polaris is best for Kubernetes teams that want to standardize configuration checks across manifests and cluster workloads, particularly those able to maintain their own JSON Schema policies and decide which findings should block deployment. It is less suited to teams looking for a general infrastructure policy tool or built-in cross-cluster history and integrations from Polaris alone.

Pros and cons

• Pros: More than 30 built-in policies cover security, reliability, resource sizing, and image practices, giving teams a broad starting point for Kubernetes configuration reviews.
• Pros: Dashboard, admission-controller, and CLI modes support both pre-deployment checks and cluster enforcement.
• Pros: Automatic fixes for supported issues can address missing limits and probes without requiring every correction to be made manually.
• Cons: The validating webhook needs a valid TLS certificate, adding setup work for teams that want admission enforcement.
• Cons: Automatic remediation applies only to supported issues, so teams still need to review findings and handle other fixes themselves.

Alternatives

For policy validation focused on Terraform, Google Cloud Terraform Policy Validation is a free beta client-side tool; Polaris instead targets Kubernetes resource configuration.

Open Policy Agent is another free, open-source policy engine under the Apache License 2.0. Choose between them based on whether Polaris's built-in Kubernetes checks and its dashboard, webhook, and CLI modes suit your workflow.

Terraform offers a free plan capped at 500 managed resources, one concurrent remote run, and one concurrent agent run, plus a free trial. Choose it when those Terraform capabilities match your needs rather than Polaris's Kubernetes-focused checks.

AWS CloudFormation is a free service for CloudFormation itself, while underlying AWS resources are billed at their own rates. It is a relevant alternative for infrastructure managed through CloudFormation rather than Kubernetes configuration.

Cloud Custodian is a free, open-source tool under Apache 2.0. Conftest is also free and open source under Apache License 2.0. cfn-lint is free under MIT-0 and supports Python 3.10–3.14. KICS is a free open-source project. These alternatives may suit readers comparing other infrastructure policy and validation tools.

Browse Infrastructure Policy as Code Tools, Infrastructure as Code Security Software, and Kubernetes Security Software for related categories.

Verdict

Choose Fairwinds Polaris if your team needs free, Kubernetes-specific policy checks across local manifests and cluster workloads, with optional enforcement and targeted automatic remediation. Its built-in policies and flexible run modes are the main reasons to choose it; look elsewhere if you need general infrastructure policy coverage or multi-cluster history and integrations beyond Polaris.