README.md

Setting up Minikube to have routable Cluster IPs and External IPs

This guide will show you how to access services within your minikube instance.

Accessing Cluster IPs

First, we will need to add a route to minikube.

This oneliner gets the ClusterIP range from minikube's config and adds a route.

sudo route -n add -net $(cat ~/.minikube/profiles/minikube/config.json | jq -r ".KubernetesConfig.ServiceCIDR") $(minikube ip)

To test, deploy nginx.

kubectl run nginx --image=nginx --replicas=1
kubectl expose deployment nginx --port=80 --target-port=80 --type=LoadBalancer

And connect to it:

nginx_ip=$(kubectl get svc nginx -o jsonpath='{.spec.clusterIP}')
curl $nginx_ip

Assigning External IPs

Minikube does not provision an external IP when type=LoadBalancer. This prevents some apps that talk to the k8s API from working properly.

A custom controller must be run on your Minikube cluster to enable this functionality.

DO NOT RUN THIS ON A NON-MINIKUBE CLUSTER!!

kubectl run minikube-lb-patch --replicas=1 --image=elsonrodriguez/minikube-lb-patch:0.1 --namespace=kube-system

This controller will assign the External IP to the ClusterIP, which has been made routable in the previous section.

kubectl  get svc
NAME         CLUSTER-IP   EXTERNAL-IP   PORT(S)        AGE
kubernetes   10.0.0.1     <none>        443/TCP        18d
nginx        10.0.0.98    10.0.0.98     80:31834/TCP   40s

Nothing should change connectivity-wise, however your app can now just scrape the usual field for external ip:

nginx_external_ip=$(kubectl get svc nginx -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
curl $nginx_external_ip

Teardown

To undo all this:

kubectl  delete deployment nginx
kubectl  delete svc nginx
kubectl  delete deployment minikube-lb-patch -nkube-system
sudo route -n delete -net $(cat ~/.minikube/profiles/minikube/config.json | jq -r ".KubernetesConfig.ServiceCIDR") $(minikube ip)