Running Kubernetes Without kube-proxy Using Cilium: Step‑by‑Step Guide

Introduction

Many have heard that Cilium, powered by eBPF, offers high performance and network policy support, and can replace the traditional kube-proxy component. This guide documents a hands‑on installation of Cilium as a CNI on a Kubernetes cluster without installing kube‑proxy.

Environment

Kubernetes version: v1.21.3

Cilium version: v1.10.3

Installation method: kubeadm

Cilium networking mode: vxlan

OS: Ubuntu 18.04

Cluster size: 1 master, 2 nodes

Procedure

Initialize the master node while skipping the kube‑proxy addon:

<code>kubeadm init \
  --apiserver-advertise-address=10.211.55.50 \
  --image-repository registry.aliyuncs.com/google_containers \
  --kubernetes-version v1.21.3 \
  --service-cidr=10.96.0.0/12 \
  --pod-network-cidr=10.244.0.0/16 \
  --ignore-preflight-errors=all \
  --skip-phases=addon/kube-proxy</code>

Join the two worker nodes to the cluster:

<code>kubeadm join 10.211.55.50:6443 \
  --token ouez6j.02ms269v8i4psl7p \
  --discovery-token-ca-cert-hash sha256:5fdafe0fe1adb3b60cd7bc33f033f028279a94a3944816424cc7f5bb498f6868</code>

Add the Cilium Helm repository:

<code>helm repo add cilium https://helm.cilium.io/</code>

Install Cilium with the kubeProxyReplacement=strict option:

<code>helm install cilium cilium/cilium \
  --version 1.10.3 \
  --namespace kube-system \
  --set kubeProxyReplacement=strict \
  --set k8sServiceHost=10.211.55.50 \
  --set k8sServicePort=6443</code>

Verify Cilium pods are running:

<code># kubectl -n kube-system get pods -l k8s-app=cilium
cilium-8gwg2   1/1 Running   0   8m4s
cilium-t9ffc   1/1 Running   0   8m39s
cilium-x42r6   1/1 Running   0   8m16s</code>

Confirm that the kube‑proxy component is absent:

<code># kubectl get po -n kube-system
... (output shows no kube-proxy pods) ...</code>

Check Cilium status to ensure a correct installation:

<code># kubectl -n kube-system exec cilium-t9ffc -- cilium status
... (status output confirming OK, KubeProxyReplacement: Strict, etc.) ...</code>

Deploy an Nginx application to test network connectivity:

<code># cat deployment-nginx.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
spec:
  selector:
    matchLabels:
      run: nginx
  replicas: 4
  template:
    metadata:
      labels:
        run: nginx
    spec:
      containers:
      - name: nginx
        image: nginx
        ports:
        - containerPort: 80

kubectl create -f deployment-nginx.yaml</code>

Create a NodePort service for the Nginx deployment:

<code>kubectl expose deployment nginx --type=NodePort --port=80</code>

Validate access via NodePort and ClusterIP:

<code># curl 127.0.0.1:31126   # returns Nginx welcome page
# curl 10.97.209.103    # returns Nginx welcome page</code>

Conclusion

The cluster operates normally without the kube‑proxy component, demonstrating that Cilium can fully replace kube‑proxy in a Kubernetes environment. Further topics such as Cilium system requirements, networking modes, and policy features will be covered in future articles.