kubeadm: fix some issues in the upgrade-1.13 doc (#11629)

- use "control plane" instead of "master".
- upgrade a kubelet on the CP node only after the CP was upgraded.
- also instruct the user to update to the latest patch version of 1.13.

content/en/docs/tasks/administer-cluster/kubeadm/kubeadm-upgrade-1-13.md

@@ -33,18 +33,38 @@ This page explains how to upgrade a Kubernetes cluster created with `kubeadm` fr
 
 {{% capture steps %}}
 
-## Upgrade the control plane
+## Determine which version to upgrade to
 
-1.  On your master node, upgrade kubeadm:
+1.  Find the latest stable 1.13 version:
 
-    {{< tabs name="k8s_install" >}}
+    {{< tabs name="k8s_install_versions" >}}
     {{% tab name="Ubuntu, Debian or HypriotOS" %}}
-    apt-mark unhold kubelet kubeadm && \
+    apt update
-    apt-get update && apt-get upgrade -y kubelet kubeadm && \
+    apt-cache policy kubeadm
-    apt-mark hold kubelet kubeadm
+    # find the latest 1.13 version in the list
+    # it should look like 1.13.x-00, where x is the latest patch
     {{% /tab %}}
     {{% tab name="CentOS, RHEL or Fedora" %}}
-    yum upgrade -y kubeadm --disableexcludes=kubernetes
+    yum list --showduplicates kubeadm --disableexcludes=kubernetes
+    # find the latest 1.13 version in the list
+    # it should look like 1.13.x-0, where x is the latest patch
+    {{% /tab %}}
+    {{< /tabs >}}
+
+## Upgrade the control plane node
+
+1.  On your control plane node, upgrade kubeadm:
+
+    {{< tabs name="k8s_install_kubeadm" >}}
+    {{% tab name="Ubuntu, Debian or HypriotOS" %}}
+    # replace x in 1.13.x-00 with the latest patch version
+    apt-mark unhold kubeadm && \
+    apt-get update && apt-get install -y kubeadm=1.13.x-00 && \
+    apt-mark hold kubeadm
+    {{% /tab %}}
+    {{% tab name="CentOS, RHEL or Fedora" %}}
+    # replace x in 1.13.x-0 with the latest patch version
+    yum install -y kubeadm-1.13.x-0 --disableexcludes=kubernetes
     {{% /tab %}}
     {{< /tabs >}}
 
@@ -182,7 +202,39 @@ This page explains how to upgrade a Kubernetes cluster created with `kubeadm` fr
     Check the [addons](/docs/concepts/cluster-administration/addons/) page to
     find your CNI provider and see whether additional upgrade steps are required.
 
-## Upgrade master and node packages
+1.  Upgrade the kubelet on the control plane node:
+
+    {{< tabs name="k8s_install_kubelet" >}}
+    {{% tab name="Ubuntu, Debian or HypriotOS" %}}
+    # replace x in 1.13.x-00 with the latest patch version
+    apt-mark unhold kubelet && \
+    apt-get update && apt-get install -y kubelet=1.13.x-00 && \
+    apt-mark hold kubelet
+    {{% /tab %}}
+    {{% tab name="CentOS, RHEL or Fedora" %}}
+    # replace x in 1.13.x-0 with the latest patch version
+    yum install -y kubelet-1.13.x-0 --disableexcludes=kubernetes
+    {{% /tab %}}
+    {{< /tabs >}}
+
+## Ugrade kubectl on all nodes
+
+1.  Upgrade kubectl on all nodes:
+
+    {{< tabs name="k8s_install_kubectl" >}}
+    {{% tab name="Ubuntu, Debian or HypriotOS" %}}
+    # replace x in 1.13.x-00 with the latest patch version
+    apt-mark unhold kubectl && \
+    apt-get update && apt-get install -y kubectl=1.13.x-00 && \
+    apt-mark hold kubectl
+    {{% /tab %}}
+    {{% tab name="CentOS, RHEL or Fedora" %}}
+    # replace x in 1.13.x-0 with the latest patch version
+    yum install -y kubectl-1.13.x-0 --disableexcludes=kubernetes
+    {{% /tab %}}
+    {{< /tabs >}}
+
+## Drain control plane and worker nodes
 
 1.  Prepare each node for maintenance by marking it unschedulable and evicting the workloads. Run:
 
@@ -190,7 +242,7 @@ This page explains how to upgrade a Kubernetes cluster created with `kubeadm` fr
     kubectl drain $NODE --ignore-daemonsets
     ```
 
-    On the master node, you must add `--ignore-daemonsets`:
+    On the control plane node, you must add `--ignore-daemonsets`:
 
     ```shell
     kubectl drain ip-172-31-85-18
@@ -209,27 +261,36 @@ This page explains how to upgrade a Kubernetes cluster created with `kubeadm` fr
     node "ip-172-31-85-18" drained
     ```
 
+## Upgrade the kubelet config on worker nodes
+
+1.  On each node except the control plane node, upgrade the kubelet config:
+
+    ```shell
+    kubeadm upgrade node config --kubelet-version v1.13.x
+    ```
+
+    Replace `x` with the patch version you picked for this ugprade.
+
+
+## Upgrade kubeadm and the kubelet on worker nodes
+
 1.  Upgrade the Kubernetes package version on each `$NODE` node by running the Linux package manager for your distribution:
 
-    {{< tabs name="k8s_install" >}}
+    {{< tabs name="k8s_kubelet_and_kubeadm" >}}
     {{% tab name="Ubuntu, Debian or HypriotOS" %}}
+    # replace x in 1.13.x-00 with the latest patch version
     apt-get update
-    apt-get upgrade -y kubelet kubeadm
+    apt-get install -y kubelet=1.13.x-00 kubeadm=1.13.x-00
     {{% /tab %}}
     {{% tab name="CentOS, RHEL or Fedora" %}}
-    yum upgrade -y kubelet kubeadm --disableexcludes=kubernetes
+    # replace x in 1.13.x-0 with the latest patch version
+    yum install -y kubelet-1.13.x-0 kubeadm-1.13.x-0 --disableexcludes=kubernetes
     {{% /tab %}}
     {{< /tabs >}}
 
-## Upgrade kubelet on each node
+## Restart the kubelet for all nodes
 
-1.  On each node except the master node, upgrade the kubelet config:
+1.  Restart the kubelet process for all nodes:
-
-    ```shell
-    kubeadm upgrade node config --kubelet-version $(kubelet --version | cut -d ' ' -f 2)
-    ```
-
-1.  Restart the kubelet process:
 
     ```shell
     systemctl restart kubelet