kubernetes-the-hard-way/docs/05-kubernetes-configuration...

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# Generating Kubernetes Configuration Files for Authentication
In this lab you will generate [Kubernetes configuration files](https://kubernetes.io/docs/concepts/configuration/organize-cluster-access-kubeconfig/), 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 `controller manager`, `kubelet`, `kube-proxy`, and `scheduler` clients and the `admin` user.
### 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 $(gcloud config get-value compute/region) \
--format 'value(address)')
```
### The kubelet Kubernetes Configuration File
When generating kubeconfig files for Kubelets the client certificate matching the Kubelet's node name must be used. This will ensure Kubelets are properly authorized by the Kubernetes [Node Authorizer](https://kubernetes.io/docs/admin/authorization/node/).
> The following commands must be run in the same directory used to generate the SSL certificates during the [Generating TLS Certificates](04-certificate-authority.md) lab.
Generate a kubeconfig file for each worker node:
```
for instance in worker-0 worker-1 worker-2; do
kubectl config set-cluster kubernetes-the-hard-way \
--certificate-authority=ca.pem \
--embed-certs=true \
--server=https://${KUBERNETES_PUBLIC_ADDRESS}:6443 \
--kubeconfig=${instance}.kubeconfig
kubectl config set-credentials system:node:${instance} \
--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 system: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=system:kube-proxy \
--kubeconfig=kube-proxy.kubeconfig
kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig
}
```
Results:
```
kube-proxy.kubeconfig
```
### The kube-controller-manager Kubernetes Configuration File
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
```
### The kube-scheduler Kubernetes Configuration File
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
```
### The admin Kubernetes Configuration File
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
```
##
## 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
```
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
gcloud compute scp admin.kubeconfig kube-controller-manager.kubeconfig kube-scheduler.kubeconfig ${instance}:~/
done
```
Next: [Generating the Data Encryption Config and Key](06-data-encryption-keys.md)