3.4 KiB
Generating Kubernetes Configuration Files for Authentication
In this lab you will generate Kubernetes configuration files, also known as kubeconfigs, which enable Kubernetes clients to locate and authenticate to the Kubernetes API Servers.
Client Authentication Configs
In this section you will generate kubeconfig files for the kubelet
and kube-proxy
clients.
The
scheduler
andcontroller manager
access the Kubernetes API Server locally over an insecure API port which does not require authentication. The Kubernetes API Server's insecure port is only enabled for local access.
Kubernetes Public IP Address
Each kubeconfig requires a Kubernetes API Server to connect to. To support high availability the IP address assigned to the external load balancer fronting the Kubernetes API Servers will be used.
Retrieve the kubernetes-the-hard-way
static IP address:
KUBERNETES_PUBLIC_ADDRESS=$(gcloud compute addresses describe kubernetes-the-hard-way \
--region $(gcloud config get-value compute/region) \
--format 'value(address)')
The kubelet Kubernetes Configuration File
When generating kubeconfig files for Kubelets the client certificate matching the Kubelet's node name must be used. This will ensure Kubelets are properly authorized by the Kubernetes Node Authorizer.
Generate a kubeconfig file for each worker node:
for instance in worker-0 worker-1 worker-2; do
kubectl config set-cluster kubernetes-the-hard-way \
--certificate-authority=ca.pem \
--embed-certs=true \
--server=https://${KUBERNETES_PUBLIC_ADDRESS}:6443 \
--kubeconfig=${instance}.kubeconfig
kubectl config set-credentials system:node:${instance} \
--client-certificate=${instance}.pem \
--client-key=${instance}-key.pem \
--embed-certs=true \
--kubeconfig=${instance}.kubeconfig
kubectl config set-context default \
--cluster=kubernetes-the-hard-way \
--user=system:node:${instance} \
--kubeconfig=${instance}.kubeconfig
kubectl config use-context default --kubeconfig=${instance}.kubeconfig
done
Results:
worker-0.kubeconfig
worker-1.kubeconfig
worker-2.kubeconfig
The kube-proxy Kubernetes Configuration File
Generate a kubeconfig file for the kube-proxy
service:
kubectl config set-cluster kubernetes-the-hard-way \
--certificate-authority=ca.pem \
--embed-certs=true \
--server=https://${KUBERNETES_PUBLIC_ADDRESS}:6443 \
--kubeconfig=kube-proxy.kubeconfig
kubectl config set-credentials kube-proxy \
--client-certificate=kube-proxy.pem \
--client-key=kube-proxy-key.pem \
--embed-certs=true \
--kubeconfig=kube-proxy.kubeconfig
kubectl config set-context default \
--cluster=kubernetes-the-hard-way \
--user=kube-proxy \
--kubeconfig=kube-proxy.kubeconfig
kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig
Results:
kube-proxy.kubeconfig
Distribute the Kubernetes Configuration Files
Copy the appropriate kubelet
and kube-proxy
kubeconfig files to each worker instance:
for instance in worker-0 worker-1 worker-2; do
gcloud compute scp ${instance}.kubeconfig kube-proxy.kubeconfig ${instance}:~/
done