Lab 2.1 - Prep Ubuntu
=====================

.. note::  This installation will utilize Ubuntu v18.04 (Bionic)

.. important:: The following commands need to be run on all three nodes
   unless otherwise specified.

#. From the jumpbox open **mRemoteNG** and start a session to each of the
   following servers. The sessions are pre-configured to connect with the
   default user “ubuntu”.

   - kube-master1
   - kube-node1
   - kube-node2

   .. tip:: These sessions should be running from the previous Docker lab.

   .. image:: images/MremoteNG.png

#. If not already done from the previous Docker lab elevate to "root"

   .. code-block:: bash

      su -

      #When prompted for password enter "default" without the quotes

   Your prompt should change to root@ at the start of the line :

   .. image:: images/rootuser.png

#. For your convenience we've already added the host IP & names to /etc/hosts.
   Verify the file

   .. code-block:: bash

      cat /etc/hosts

   The file should look like this:

   .. image:: images/ubuntu-hosts-file.png

   If entries are not there add them to the bottom of the file be editing
   "/etc/hosts" with 'vim'

   .. code-block:: bash

      vim /etc/hosts

      #cut and paste the following lines to /etc/hosts

      10.1.1.7    kube-master1
      10.1.1.8    kube-node1
      10.1.1.9    kube-node2

#. The linux swap file needs to be disabled, this is not the case by default.
   Again for your convenience we disabled swap. Verify the setting

   .. important:: Running a swap file is incompatible with Kubernetes.  Lets
      use the linux top command, which allows users to monitor processes and
      system resource usage

   .. code-block:: bash

      top

   .. image:: images/top.png

   If you see a number other than "0" you need to run the following commands
   (press 'q' to quit top)

   .. code-block:: bash

      swapoff -a

      vim /etc/fstab

      #rem out the highlighted line below by adding "#" to the beginning of the line, write and save the file by typing ":wq"

   .. image:: images/disable-swap.png

#. Ensure the OS is up to date, run the following command

   .. tip:: You can skip this step if it was done in the previous Docker lab.

   .. code-block:: bash

      apt update && apt upgrade -y

      #This can take a few seconds to several minute depending on demand to download the latest updates for the OS.

#. Install docker-ce

   .. attention:: This was done earlier in
      `Appendix 1 / Module1 / Lab 1.1: Install Docker <../appendix1/module1/lab1.html>`_
      . If skipped go back and install Docker by clicking the link.

#. Configure docker to use the correct cgroupdriver

   .. important:: The cgroupdrive for docker and kubernetes have to match.
      Kubernetes defaults to "systemd". In this lab "systemd" is the correct
      driver.

   .. note:: This next part can be a bit tricky - just copy/paste the 5 lines
      below exactly as they are and paste via buffer to the CLI (and press
      return when done)

   .. code-block:: bash

      cat << EOF > /etc/docker/daemon.json
      {
      "exec-opts": ["native.cgroupdriver=systemd"]
      }
      EOF

   It should look something like this image below:

   .. image:: images/goodEOL.png
      :scale: 50%

#. Add the kubernetes repo

   .. code-block:: bash

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

      cat <<EOF > /etc/apt/sources.list.d/kubernetes.list
      deb http://apt.kubernetes.io/ kubernetes-xenial main
      EOF

#. Install the kubernetes packages

   .. code-block:: bash

      apt update && apt install kubelet kubeadm kubectl -y

Limitations
-----------

.. seealso:: For a full list of the limitations go here:
   `kubeadm limitations <http://kubernetes.io/docs/getting-started-guides/kubeadm/#limitations>`_

.. important:: The cluster created has a single master, with a single etcd
   database running on it. This means that if the master fails, your cluster
   loses its configuration data and will need to be recreated from scratch.