Fairwinds Polaris

Overview

Fairwinds Polaris is an open-source policy engine for checking Kubernetes resource configuration. It suits teams that want configuration checks in their deployment workflow without a paid plan. Its chief strength is flexibility: teams can inspect cluster workloads, validate admission requests, or check manifests in CI/CD; admission validation does, however, require a valid TLS certificate.

Key features

Polaris includes more than 30 built-in policies and lets teams define additional checks with JSON Schema. The policies 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 missing or latest image tags and checks image pull policy. This range makes Polaris useful for teams addressing both security-sensitive defaults and day-to-day deployment consistency.

Teams can run Polaris as a dashboard, admission controller, or command-line tool. The dashboard can run in a cluster or locally using credentials in KUBECONFIG, and can audit local files instead of a live cluster. The CLI checks local YAML files in CI/CD, bringing checks into the workflow before deployment rather than relying only on cluster review.

Admission enforcement has a clear distinction between severity levels: the validating webhook rejects workloads that trigger danger-level checks, while warning-level checks pass and appear in the dashboard or webhook logs. A mutating webhook can automatically fix supported issues, including missing limits and probes and some unsafe security settings; the CLI can also remediate issues according to policy criteria. That reduces some manual correction, but remediation applies only to supported issues.

Polaris can be installed as a Helm chart. Its container images are signed and tags are immutable; the documentation recommends full version tags or digest pinning. Fairwinds says it is SOC 2 Type II compliant. Teams that need multi-cluster history or integrations with Slack, Datadog, and Jira are directed to Fairwinds Insights, which includes Polaris findings and records results across clusters with remediation guidance.

Pricing

Polaris (Open Source) costs nothing. The free, open-source policy engine is aimed at small teams, and no paid Polaris plan is described. That makes it a straightforward fit when teams can operate the tool themselves; organizations needing the multi-cluster history and integrations associated with Fairwinds Insights should consider that product instead.

Platforms

Polaris is listed for Linux, macOS, Windows, self-hosted, and web use. Its Kubernetes dashboard can be installed with kubectl or Helm, while the local dashboard and CLI support file-based review workflows.

Who it's for

Polaris is a strong fit for Kubernetes teams that want policy checks at more than one stage: local YAML review in CI/CD, dashboard audits, and admission enforcement. Teams can use its built-in checks or write custom policies, and smaller teams can start without a software charge. It is less suited to teams that need multi-cluster findings history or the Slack, Datadog, and Jira integrations offered through Fairwinds Insights.

Pros and cons

• Pros: More than 30 built-in policies cover security, reliability, resource settings, and images, so teams can address several common configuration concerns with one engine.
• Pros: Dashboard, admission, and CLI modes support checks in clusters and before deployment, rather than limiting review to one workflow stage.
• Pros: Automatic remediation can correct supported configuration issues, including missing resource limits and probes.
• Cons: The validating webhook requires a valid TLS certificate, adding a setup requirement for admission enforcement.
• Cons: Automatic fixes cover supported issues only, so teams should not expect every policy finding to be corrected for them.
• Cons: Multi-cluster history and Slack, Datadog, and Jira integrations are associated with Fairwinds Insights, not the standalone Polaris workflow.

Alternatives

For broader infrastructure-as-code security, compare Infrastructure as Code Security Software; for Kubernetes-focused choices, see Kubernetes Security Software or Infrastructure Policy as Code Tools.

Snyk Open Source is worth considering when a freemium tool with a monthly Free plan capped at five projects and access to Snyk Open Source (SCA) better matches the task. Aikido CSPM offers a free Developer plan with two users and capped repo, container image, domain, and cloud-account allowances, making it an alternative when those limits fit. AWS CloudFormation is a free service for CloudFormation itself, but underlying AWS resources are billed at their own rates; consider it when the focus is CloudFormation rather than Polaris's Kubernetes configuration checks. Conftest is a free, Apache License 2.0 open-source option. KloudSec IaC Security has a free tier with scan quotas and a free trial, which may suit teams seeking a quota-based IaC security service. kube-score is a free, MIT-licensed alternative for teams considering another open-source Kubernetes tool. Trivy is a free, Apache-2.0 licensed open-source scanner. CFRipper is free Apache-2.0 licensed software for CloudFormation templates.

Verdict

Choose Polaris if your Kubernetes team wants a free, open-source way to check configuration across dashboard, admission, and CI/CD workflows, with built-in policies and some automated remediation. Its strongest case is that breadth of workflow and policy coverage at no software cost. Look elsewhere if multi-cluster history and Slack, Datadog, or Jira integrations are requirements; Fairwinds points those teams to Insights.