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.
In this section you will generate kubeconfig files for the controller manager
, kubelet
and scheduler
clients and the admin
user.
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=$(openstack server show k8sosp.${DOMAIN} -f json -c addresses | jq -r '.["addresses"]["kubernetes-the-hard-way"]|last')
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.
The following commands must be run in the same directory used to generate the SSL certificates during the Generating TLS Certificates lab.
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:${instance}.${DOMAIN} \
--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}.${DOMAIN} \
--kubeconfig=${instance}.kubeconfig
kubectl config use-context default --kubeconfig=${instance}.kubeconfig
done
Results:
worker-0.kubeconfig
worker-1.kubeconfig
worker-2.kubeconfig
Generate a kubeconfig file for the kube-controller-manager
service:
{
kubectl config set-cluster kubernetes-the-hard-way \
--certificate-authority=ca.pem \
--embed-certs=true \
--server=https://127.0.0.1:6443 \
--kubeconfig=kube-controller-manager.kubeconfig
kubectl config set-credentials system:kube-controller-manager \
--client-certificate=kube-controller-manager.pem \
--client-key=kube-controller-manager-key.pem \
--embed-certs=true \
--kubeconfig=kube-controller-manager.kubeconfig
kubectl config set-context default \
--cluster=kubernetes-the-hard-way \
--user=system:kube-controller-manager \
--kubeconfig=kube-controller-manager.kubeconfig
kubectl config use-context default --kubeconfig=kube-controller-manager.kubeconfig
}
Results:
kube-controller-manager.kubeconfig
Generate a kubeconfig file for the kube-scheduler
service:
{
kubectl config set-cluster kubernetes-the-hard-way \
--certificate-authority=ca.pem \
--embed-certs=true \
--server=https://127.0.0.1:6443 \
--kubeconfig=kube-scheduler.kubeconfig
kubectl config set-credentials system:kube-scheduler \
--client-certificate=kube-scheduler.pem \
--client-key=kube-scheduler-key.pem \
--embed-certs=true \
--kubeconfig=kube-scheduler.kubeconfig
kubectl config set-context default \
--cluster=kubernetes-the-hard-way \
--user=system:kube-scheduler \
--kubeconfig=kube-scheduler.kubeconfig
kubectl config use-context default --kubeconfig=kube-scheduler.kubeconfig
}
Results:
kube-scheduler.kubeconfig
Generate a kubeconfig file for the admin
user:
{
kubectl config set-cluster kubernetes-the-hard-way \
--certificate-authority=ca.pem \
--embed-certs=true \
--server=https://127.0.0.1:6443 \
--kubeconfig=admin.kubeconfig
kubectl config set-credentials admin \
--client-certificate=admin.pem \
--client-key=admin-key.pem \
--embed-certs=true \
--kubeconfig=admin.kubeconfig
kubectl config set-context default \
--cluster=kubernetes-the-hard-way \
--user=admin \
--kubeconfig=admin.kubeconfig
kubectl config use-context default --kubeconfig=admin.kubeconfig
}
Results:
admin.kubeconfig
Copy the appropriate kubelet
kubeconfig file to each worker instance:
for instance in worker-0 worker-1 worker-2; do
scp ${instance}.kubeconfig ${instance}.${DOMAIN}:
done
Copy the appropriate kube-controller-manager
and kube-scheduler
kubeconfig files to each controller instance:
for instance in controller-0 controller-1 controller-2; do
scp admin.kubeconfig kube-controller-manager.kubeconfig kube-scheduler.kubeconfig ${instance}.${DOMAIN}:
done