Installing Kubernetes components (kubelet and kubeadm)

Next we will need to SSH into all four of the instances and install the Kubernetes components.

As root, perform the following steps on all four instances:

1. Update packages and install the apt-transport-https package so we can download from sources   that use HTTPS:

   $ apt-get update 
   $ apt-get install -y apt-transport-https

2. Install the Google Cloud public key:

   $ curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg |
   apt-key add -    

3. Next, create a source list for the Kubernetes package downloads with your favorite editor:

   $ vi /etc/apt/sources.list.d/kubernetes.list

4. Use the following as contents for this file and save:

   deb http://apt.kubernetes.io/ kubernetes-xenial main

Listing 1-1. /etc/apt/sources.list.d/kubernetes.list

5. Update your sources once more:

   $ apt-get update

6. Install Docker and the core Kubernetes components:

   $ apt-get install -y docker.io 
   $ apt-get install -y kubelet kubeadm kubectl kubernetes-cni