Update kubeadm install doc for v1.8

docs/setup/independent/install-kubeadm.md

@@ -10,7 +10,7 @@ This page shows how to use install kubeadm.
 
 {% capture prerequisites %}
 
-* One or more machines running Ubuntu 16.04+, CentOS 7 or HypriotOS v1.0.1+
+* One or more machines running Ubuntu 16.04+, CentOS 7, RHEL 7, Fedora 25 (YMMV) or HypriotOS v1.0.1+
 * 1GB or more of RAM per machine (any less will leave little room for your apps)
 * Full network connectivity between all machines in the cluster (public or private network is fine)
 * Unique MAC address and product_uuid for every node
@@ -55,38 +55,50 @@ documentation for the plugins about what port(s) those need.
 ## Installing Docker
 
 On each of your machines, install Docker.
-Version 1.12 is recommended, but v1.10 and v1.11 are known to work as well.
-Versions 1.13 and 17.03+ have not yet been tested and verified by the Kubernetes node team.
-For installation instructions, see
-[Install Docker](https://docs.docker.com/engine/installation/).
+Version v1.12 is recommended, but v1.11, v1.13 or 17.03 are known to work as well.
+Versions 17.06+ _might work_, but have not yet been tested and verified by the Kubernetes node team.
 
-## Installing kubectl
+You can for instance use the following commands to install Docker on your system:
 
-On each of your machines,
-[install kubectl](/docs/tasks/tools/install-kubectl/).
-You only need kubectl on the master and/or your workstation, but it can be
-useful to have on the other nodes as well.
+{% capture ubuntu %}
 
-## Installing kubelet and kubeadm
+  ``` bash
+  apt-get update
+  apt-get install -y docker.io
+  ```
 
-You will install these packages on all of your machines:
+{% endcapture %}
+
+{% capture centos %}
+
+  ``` bash
+  yum install -y docker
+  systemctl enable docker && systemctl start docker
+  ```
+
+{% endcapture %}
+
+{% assign tab_names = "Ubuntu or HypriotOS;CentOS, RHEL or Fedora" | split: ';' | compact %}
+{% assign tab_contents = site.emptyArray | push: ubuntu | push: centos %}
+
+{% include tabs.md %}
 
-* `kubelet`: the component that runs on all of the machines in your cluster
-    and does things like starting pods and containers.
+
+## Installing kubeadm, kubelet and kubectl
+
+You will install these packages on all of your machines:
 
 * `kubeadm`: the command to bootstrap the cluster.
 
-**Note:** If you already have kubeadm installed, you should do a `apt-get update &&
-apt-get upgrade` or `yum update` to get the latest version of kubeadm. See the
-kubeadm release notes if you want to read about the different [kubeadm
-releases](https://github.com/kubernetes/kubeadm/blob/master/CHANGELOG.md).
+* `kubelet`: the component that runs on all of the machines in your cluster
+    and does things like starting pods and containers.
 
-For each machine:
+* `kubectl`: the command line util to talk to your cluster.
 
-* SSH into the machine and become root if you are not already (for example,
-  run `sudo -i`).
+Please proceed with executing the following commands based on your OS as the `root` user by SSH-ing
+into each machine. You may for example become `root` by executing `sudo -i`.
 
-* If the machine is running Ubuntu or HypriotOS, run:
+{% capture ubuntu %}
 
   ``` bash
   apt-get update && apt-get install -y apt-transport-https
@@ -95,10 +107,12 @@ For each machine:
   deb http://apt.kubernetes.io/ kubernetes-xenial main
   EOF
   apt-get update
-  apt-get install -y kubelet kubeadm
+  apt-get install -y kubelet kubeadm kubectl
   ```
 
-* If the machine is running CentOS, run:
+{% endcapture %}
+
+{% capture centos %}
 
   ``` bash
   cat <<EOF > /etc/yum.repos.d/kubernetes.repo
@@ -116,13 +130,21 @@ For each machine:
   systemctl enable kubelet && systemctl start kubelet
   ```
 
+**Note:** Disabling SELinux by running `setenforce 0` is required to allow
+containers to access the host filesystem, which is required for the `kubeadm init`
+process to complete successfully. You have to do this until SELinux support is
+improved in the kubelet.
+
+{% endcapture %}
+
+{% assign tab_names = "Ubuntu or HypriotOS;CentOS, RHEL or Fedora" | split: ';' | compact %}
+{% assign tab_contents = site.emptyArray | push: ubuntu | push: centos %}
+
+{% include tabs.md %}
+
 The kubelet is now restarting every few seconds, as it waits in a crashloop for
 kubeadm to tell it what to do.
 
-**Note:** Disabling SELinux by running `setenforce 0` is required to allow
-containers to access the host filesystem, which is required by pod networks for
-example. You have to do this until SELinux support is improved in the kubelet.
-
 {% endcapture %}
 
 {% capture whatsnext %}