Cilium 1.0: eBPF-Powered Networking Reaches GA

Introduction

April 24, 2018 marked the 1.0 GA release of Cilium, the eBPF-based Container Network Interface (CNI) plugin built for secure, high-performance Kubernetes clusters. Cilium 1.0 focuses on production stability, observability, and deep service-aware policy for microservices.

Official Highlights

1. Production-Ready Data Plane

• eBPF programs compiled ahead of time for predictable startup performance.
• Deterministic policy enforcement across Linux kernel 4.4–4.14.
• Automatic fallback to native Linux routing when eBPF is unavailable.

2. Layer 7 Aware Policies

• Envoy proxy integration unlocks HTTP, gRPC, and Kafka-aware policies.
• Operators can combine L3/L4 identity with L7 intents in a single CRD.
• Mutual TLS metadata is plumbed into policy decisions for service meshes.

3. Transparent Encryption & Routing

• IPsec-based transparent encryption for east-west traffic without application changes.
• Direct Server Return (DSR) keeps load-balanced traffic efficient at scale.
• Native IPv6/IPv4 dual-stack support.

Implementation Tips

• Kernel readiness: validate your nodes run Linux ≥ 4.9 with BPF enabled and CONFIG_BPF_JIT toggled on.
• Gradual rollout: start with kube-system workloads, then migrate namespaces by label with ciliumEndpoint status checks.
• Prometheus hooks: scrape /metrics from the Cilium agent and Envoy sidecars to baseline packet drops and policy verdicts.
• Troubleshooting: use cilium monitor and cilium policy validate during migration dry-runs.

Upgrade Checklist

1. Deploy cilium-operator for CRD lifecycle management.
2. Install the DaemonSet in parallel to your existing CNI (e.g., Calico) in a canary pool.
3. Annotate target nodes with cni.cilium.io/enabled=true and cordon/drain to swap CNIs safely.
4. Confirm kube-proxy replacement mode if running in IPVS or eBPF direct routing.
5. Update PodSecurityPolicies to allow required eBPF file descriptors and syscalls.

Ecosystem Integrations

• Works alongside Envoy, Istio 1.0, and Linkerd 2.0 without double-proxy overhead.
• Compatible with Helm 2.9 charts for automated GitOps delivery.
• Provides audit-grade flow visibility via Hubble (tech preview) for compliance teams.

Summary

Cilium 1.0 closes the gap between security and performance in container networking. By embedding enforcement directly in the kernel with eBPF, teams achieve high throughput, granular policy, and rich observability without the iptables bottleneck—perfect for modern service-mesh and microservice platforms.