# kube-vip — Virtual IP and Load Balancing for Kubernetes

> kube-vip provides a virtual IP and load balancer for both the Kubernetes control plane and service type LoadBalancer, enabling highly available clusters without external hardware or cloud load balancers.

## Install

Save as a script file and run:

# kube-vip — Virtual IP and Load Balancing for Kubernetes

## Quick Use
```bash
# Generate a static pod manifest for control plane HA
export VIP=192.168.1.100
export INTERFACE=eth0
kube-vip manifest pod 
  --interface $INTERFACE 
  --address $VIP 
  --controlplane 
  --arp 
  --leaderElection | sudo tee /etc/kubernetes/manifests/kube-vip.yaml
```

## Introduction
kube-vip provides Kubernetes clusters with a virtual IP address for the control plane and LoadBalancer-type Services without requiring external load balancers or cloud provider integrations. It is particularly valuable for bare-metal and on-premises Kubernetes deployments where cloud load balancers are unavailable.

## What kube-vip Does
- Assigns a floating virtual IP to the Kubernetes control plane for high availability
- Implements LoadBalancer-type Services on bare-metal clusters
- Uses ARP or BGP to advertise virtual IP addresses on the network
- Elects a leader node to hold the VIP using Raft-based leader election
- Runs as a static pod, DaemonSet, or standalone binary

## Architecture Overview
kube-vip runs on each control plane node and participates in leader election. The elected leader binds the virtual IP to its network interface and responds to ARP requests (layer 2 mode) or advertises the route via BGP (layer 3 mode). For Service load balancing, kube-vip watches the Kubernetes API for Services of type LoadBalancer and assigns addresses from a configured IP pool, handling traffic distribution across backends.

## Self-Hosting & Configuration
- Deploy as a static pod on control plane nodes or as a DaemonSet cluster-wide
- Configure ARP mode for simple layer 2 environments on a flat network
- Configure BGP mode for routed environments with upstream router peering
- Define IP address pools for Service LoadBalancer allocation via ConfigMap or CIDR range
- Set leader election lease duration and renewal parameters for failover speed

## Key Features
- Control plane VIP eliminates single points of failure without external dependencies
- Dual-mode networking with ARP for layer 2 and BGP for layer 3 environments
- Service LoadBalancer implementation replaces MetalLB for many use cases
- Lightweight single binary with no external dependencies
- Works with any Kubernetes distribution including K3s, kubeadm, and RKE2

## Comparison with Similar Tools
- **MetalLB** — more mature LoadBalancer implementation but does not provide control plane VIP
- **Keepalived** — traditional Linux VIP failover, requires separate configuration outside Kubernetes
- **Cloud LB (AWS NLB, GCP LB)** — managed service, not available on bare metal or edge
- **HAProxy + Keepalived** — common pattern for HA control plane, more components to manage

## FAQ
**Q: Can kube-vip replace MetalLB?**
A: For many use cases, yes. kube-vip provides both control plane VIP and Service LoadBalancer functionality in a single component. MetalLB offers more advanced features like L2/BGP co-existence and community support.

**Q: Does kube-vip work with K3s?**
A: Yes. kube-vip integrates with K3s as a DaemonSet and can provide the control plane VIP and LoadBalancer services for K3s clusters.

**Q: What is the failover time when the leader node goes down?**
A: Failover typically completes in 5-10 seconds depending on leader election lease configuration and ARP cache expiry on the network.

**Q: Can I use kube-vip in a cloud environment?**
A: It is possible but generally unnecessary since cloud providers offer native load balancers. kube-vip is designed for environments without cloud LB support.

## Sources
- https://github.com/kube-vip/kube-vip
- https://kube-vip.io/docs/

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Source: https://tokrepo.com/en/workflows/asset-4ad75332
Author: Script Depot