Cilium Has a Free API: eBPF-Powered Networking, Security, and Observability for Kubernetes

#kubernetes #networking #security #ebpf

Why Cilium Matters

Cilium replaces kube-proxy and traditional CNIs with eBPF — Linux kernel-level networking that is faster, more observable, and more secure. It is the default CNI for GKE, EKS, and AKS.

Install

helm repo add cilium https://helm.cilium.io/
helm install cilium cilium/cilium --namespace kube-system

# CLI
brew install cilium-cli
cilium status

Network Policies (L3/L4/L7)

apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
  name: allow-api
spec:
  endpointSelector:
    matchLabels:
      app: api
  ingress:
    - fromEndpoints:
        - matchLabels:
            app: frontend
      toPorts:
        - ports:
            - port: "8080"
              protocol: TCP
          rules:
            http:
              - method: GET
                path: "/api/v1/.*"

L7 filtering — allow GET on /api/v1/ but block POST. No sidecar needed.

Hubble (Observability)

# Enable Hubble
cilium hubble enable --ui

# Observe flows
hubble observe --namespace production
hubble observe --to-label app=api --verdict DROPPED

Service Mesh (No Sidecars)

cilium install --set kubeProxyReplacement=true

Cilium provides mTLS, traffic management, and observability at the kernel level — no Envoy sidecars eating your memory.

Key Features

eBPF — kernel-level performance, no overhead
L7 policies — HTTP/gRPC/Kafka-aware filtering
Hubble — real-time network observability
Service mesh — sidecar-free mTLS and load balancing
Multi-cluster — ClusterMesh for cross-cluster networking
CNCF Graduated — production standard

Resources

Need to extract network flow data, security policies, or cluster metrics? Check out my Apify tools or email spinov001@gmail.com for custom solutions.