# Generating Kubernetes Configuration Files for Authentication

In this chapter, 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 IP Address

Each kubeconfig requires a Kubernetes API Server to connect to. To support high availability the IP address assigned to the load balancer fronting the Kubernetes API Servers will be used.

Set a variable named `KUBERNETES_LB_ADDRESS`:

```
$ KUBERNETES_LB_ADDRESS=10.240.0.10
```


### 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/).

Generate a kubeconfig file for each worker node:

```
for instance in worker-1 worker-2 worker-3; do
  kubectl config set-cluster kubernetes-the-hard-way \
    --certificate-authority=ca.pem \
    --embed-certs=true \
    --server=https://${KUBERNETES_LB_ADDRESS}:6443 \
    --kubeconfig=${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-1.kubeconfig
worker-2.kubeconfig
worker-3.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_LB_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:

```
$ USERNAME=<User Name of Virtual Machines>
$ for num in 1 2 3; do
  scp -i ~/.ssh/id_rsa-k8s.pub worker-${num}.kubeconfig kube-proxy.kubeconfig ${USERNAME}@10.240.0.2${num}:~/
done
```

Copy the appropriate `kube-controller-manager` and `kube-scheduler` kubeconfig files to each controller instance:

```
$ USERNAME=<User Name of Virtual Machines>
$ for num in 1 2 3; do
  scp -i ~/.ssh/id_rsa-k8s.pub admin.kubeconfig kube-controller-manager.kubeconfig kube-scheduler.kubeconfig ${USERNAME}@10.240.0.1${num}:~/
done
```

Next: [Generating the Data Encryption Config and Key](06-data-encryption-keys.md)