Cilium

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Coverage Matrix

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Cilium Overview

Cilium is a cloud-native networking and security solution for Kubernetes that uses eBPF (Extended Berkeley Packet Filter) to dynamically program the Linux kernel. By doing so, it achieves highly efficient network routing, identity-aware policy enforcement, and fine-grained observability through Hubble. This approach avoids the overhead of traditional iptables-based CNIs, delivering better performance at scale. With Cilium, platform teams can seamlessly enforce zero-trust policies, enable transparent encryption of pod-to-pod traffic, and gain deep insights into network flows without needing application-level instrumentation.

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Chkk Coverage

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Curated Release Notes

Chkk tracks official Cilium release notes and distills them into briefings that highlight key updates, new features, security advisories, and deprecations. Rather than sifting through every upstream change, you get a concise overview of what has changed and how it might affect your clusters. For example, if Cilium removes the deprecated cidrs field from the CiliumLoadBalancerIPPool CRD, Chkk flags any IP pool definitions still using that field and helps you transition to the new blocks syntax before it impacts IP allocation.

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Preflight & Postflight Checks

Before upgrading Cilium, Chkk runs preflight checks to verify kernel capabilities, ensure your Kubernetes version is compatible, and identify any usage of deprecated APIs. It validates that key components like Hubble, Cilium DaemonSet configurations, and network policies meet the new version’s requirements. After the upgrade, postflight checks confirm your pods are using the correct Cilium agents, check for datapath errors, and ensure that all cluster nodes remain reachable. This extra validation step catches issues (e.g., resource constraints or leftover pods on outdated sidecar versions) that might otherwise cause intermittent downtime.

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Version Recommendations

Chkk continuously monitors the Cilium support matrix, pointing out when your current version is nearing EOL or has known issues impacting stability. By cross-referencing upstream release notes and Kubernetes compatibility, it suggests stable upgrade targets that reduce risk. Instead of blindly picking the newest release, operators can rely on Chkk’s recommendations for a version that aligns with long-term support guidelines, ensuring you maintain a secure and reliable platform.

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Upgrade Templates

Chkk provides two main upgrade paths for Cilium: in-place and blue-green. With an in-place upgrade, the existing Cilium DaemonSet is updated sequentially across all nodes. This minimalistic approach is straightforward but demands careful monitoring to avoid disruption. The blue-green method, on the other hand, stands up a second Cilium deployment in parallel. Operators can progressively migrate workloads to the new version, verifying stability before retiring the old. Chkk’s templates for both approaches define step-by-step commands, rollback options, and best practices—helping to minimize downtime if an unexpected issue arises mid-upgrade.

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Preverification

For major Cilium upgrades or large multi-cluster environments, Chkk’s preverification feature offers a risk-free way to test changes. It spins up a temporary environment mirroring your current configuration—complete with your Cilium CustomResourceDefinitions, network policies, and Hubble settings—and applies the new Cilium version. The simulator checks for configuration conflicts, resource bottlenecks, or datapath issues triggered by new eBPF features. This helps ensure that the real upgrade will roll out smoothly, saving you from surprises in production.

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Supported Packages

Chkk integrates seamlessly with whatever installation method you use—Helm, Kustomize, or plain Kubernetes manifests—so you can continue managing Cilium in your existing GitOps or CI/CD pipelines. It also supports private registries and custom-built images, ensuring you maintain consistency with your organization’s security and compliance mandates. Whether you apply a standard Helm chart or maintain your own patched Cilium container images, Chkk can parse your manifests or values files, detect your current version, and propose an optimized upgrade plan.

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Common Operational Considerations

• Gradual Node Upgrades: Avoid upgrading all nodes simultaneously; instead, update Cilium on a subset of nodes, validate performance, then proceed to the rest.
• Preserve Custom Configurations: If you have custom Helm values or YAML overrides for encryption, policy settings, or L7 proxies, merge those carefully when moving to a new chart or manifest.
• Kernel & eBPF Requirements: Verify that your kernel version includes the eBPF features required by the new release. Missing modules or too-strict sysctl settings can cause failures in Cilium’s datapath.
• Policy Testing: After each upgrade, test ingress and egress rules to confirm enforcement. Subtle changes in how Cilium interprets policy CRDs can disrupt traffic if you rely on advanced features like L7 filtering.
• Hubble Observability: Watch Hubble flows and metrics for anomalies. If flow logs suddenly drop or specific flows are denied, it may indicate CRD or agent misconfigurations post-upgrade.
• Track Resource Usage: Large-scale clusters running eBPF programs can stress node resources. Monitor CPU and memory usage on worker nodes, especially if you enable additional Cilium features like kube-proxy replacement.

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Additional Resources

• Cilium Documentation
• Cilium Releases
• Hubble UI Documentation