Whitelist ingress traffic to Kubernetes

Example of a Jenkins deployment with ClusterIP using Traefik ingress controller to whitelist specific IP's

These instructions enable to create a Jenkins deployment with ClusterIP (Not exposed via LoadBalancer) and expose it to selected public IP's via Traefik ingress controller.

Install Jenkins with ClusterIP service

$ helm install jenkins-release --set Master.ServiceType=ClusterIP stable/jenkins

Install Traefik

$ helm install stable/traefik --name traefik-release --namespace kube-system

Patch Traefik service to enable X-Forwarded public IP's

$ kubectl patch service traefik-release-traefik -n kube-system --patch $'spec:\n externalTrafficPolicy: Local\n'

Edit ingress.yaml

Set the public ip's or range to whitelist.

Single IP: ingress.kubernetes.io/whitelist-source-range: "64.18.13.199/32"

Multiple IP ranges (Cloudflare for example): ingress.kubernetes.io/whitelist-source-range: "103.21.244.0/22,103.22.200.0/22,103.31.4.0/22,104.16.0.0/12,108.162.192.0/18,131.0.72.0/22,141.101.64.0/18,162.158.0.0/15,172.64.0.0/13,173.245.48.0/20,188.114.96.0/20,190.93.240.0/20,197.234.240.0/22,198.41.128.0/17"

Create Ingress controller with whitelist IP's

$ kubectl create -f ingress.yaml