cert-manager

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Coverage Matrix

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cert-manager Overview

cert-manager is a Kubernetes add-on that automates issuing and renewing TLS certificates for your workloads. It integrates with multiple CAs (including ACME providers like Let’s Encrypt) to streamline certificate requests and validation. The project provides CRDs for defining issuers and certificates, along with a webhook for enforcing policy. By continuously monitoring and renewing certificates before they expire, cert-manager significantly reduces manual overhead. With proper resource tuning, it scales in both small and large clusters.

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Chkk Coverage

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Curated Release Notes

Chkk tracks cert-manager release notes to highlight new features, breaking changes, or CRD updates relevant to your environment. It alerts you to shifts like a renamed API group or removed fields so you can adapt configurations before upgrading. Each curated summary points to potential operational impacts, saving teams from combing through long changelogs. You stay focused on what matters, avoiding unexpected downtime.

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Preflight & Postflight Checks

Chkk’s preflight checks validate Kubernetes version, CRDs, and webhook readiness before any cert-manager upgrade. They also spot deprecated API usage that could fail in the new release. Postflight checks confirm healthy controller pods, functioning webhooks, and successful certificate issuance after the upgrade. This ensures certificate renewals continue uninterrupted. By quickly catching anomalies, teams can address issues early with Chkk.

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Version Recommendations

Chkk continuously tracks cert-manager’s support timeline and flags EOL risks or security patches for your version. It factors in Kubernetes compatibility to help you pick stable, fully-supported releases. Alerts arrive well before your version becomes unsafe or unmaintained. You also get suggestions on the best minor version to minimize breakage. By following these recommendations, you stay ahead of critical updates.

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Upgrade Templates

Chkk provides step-by-step templates for either in-place or blue-green cert-manager upgrades. In-place workflows update CRDs and the controller in sequence, while blue-green approaches deploy a parallel cert-manager instance before switching over. Both methods include rollback points and checks to ensure healthy certificate issuance. Automation is straightforward via Helm, Kustomize, or kubectl. Each template simplifies the overall upgrade experience.

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Preverification

Chkk can simulate each cert-manager upgrade in a test environment to identify issues early. It applies your Issuer and Certificate configurations, runs the new controller, and checks for ACME or webhook errors. This dry-run approach lets you fix problems before rolling out to production. By validating your exact setup, preverification reduces downtime risk. Quick feedback loops give you confidence for a trouble-free upgrade.

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Common Operational Considerations

• Webhook Availability & Readiness: The cert-manager webhook must be reachable by the API server to approve certificate-related custom resources. Downtime or misconfiguration can halt certificate issuance across the cluster.
• ACME Challenges: Ensure proper DNS and ingress settings for HTTP-01 or DNS-01 challenge methods. Misconfigurations can cause certificates to remain pending or fail to renew.
• Certificate Expiration Monitoring: cert-manager auto-renews certificates, but it’s critical to monitor expiring certificates and observe renewal events. Prompt alerts prevent overlooked renewals and outage risks.
• Issuer & CA Rotation: Rotating CAs or issuers requires re-issuing certificates with the new trust chain. Plan overlapping trust windows and verify the new CA is correctly propagated to workloads.
• Performance Tuning: Large volumes of certificates can strain the controller. Allocate adequate CPU/memory, monitor queue lengths, and scale replicas if issuance throughput is impacted.

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References

• cert-manager Documentation
• cert-manager Releases