What is Kubernetes kube-proxy?

Question

Accepted Answer

**kube-proxy** — network proxy on each node that maintains network rules.

**Modes:**
- **iptables** — default, uses iptables rules.
- **IPVS** — high-performance, uses Linux IPVS.
- **nftables** — Linux nftables backend.

```yaml
# kube-proxy configuration
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: "ipvs"
ipvs:
  scheduler: "rr"  # round-robin
  syncPeriod: "30s"
iptables:
  masqueradeAll: false
```

```bash
# Check kube-proxy mode
kubectl logs -n kube-system kube-proxy-xxxxx | grep "mode"

# Check IPVS rules
ipvsadm -Ln

# Check iptables rules
iptables -t nat -L KUBE-SERVICES
```

**IPVS vs iptables:**
- IPVS: better performance with many services.
- iptables: simpler, no additional dependencies.

DevOps: What is Kubernetes kube-proxy?