Lab 2.2 - Setup the Master
==========================

The master is the system where the "control plane" components run, including
etcd (the cluster database) and the API server (which the kubectl CLI
communicates with). All of these components run in pods started by kubelet
(which is why we had to setup docker first even on the master node)

.. important:: The following commands need to be run on the **master** only
   unless otherwise specified.

#. Switch back to the ssh session connected to kube-master1

   .. tip:: This session should be running from the previous if lab.
      If not simply open **mRemoteNG** and connect via the saved session.

#. Initialize kubernetes

   .. code-block:: bash

      kubeadm init --apiserver-advertise-address=10.1.1.7 --pod-network-cidr=10.244.0.0/16

   .. note::
      - The IP address used to advertise the master. 10.1.1.0/24 is the
        network for our control plane. if you don't specify the
        --apiserver-advertise-address argument, kubeadm will pick the first
        interface with a default gateway (because it needs internet access).

      - 10.244.0.0/16 is the default network used by flannel. We'll setup
        flannel in a later step.

      - Be patient this step takes a few minutes. The initialization is
        successful if you see "Your Kubernetes master has initialized
        successfully!".

   .. image:: images/cluster-setup-guide-kubeadm-init-master.png

   .. important::
      - Be sure to save the highlighted output from this command to notepad.
        You'll need this information to add your worker nodes and configure
        user administration.

      - The "kubeadm join" command is run on the nodes to register themselves
        with the master. Keep the secret safe since anyone with this token can
        add an authenticated node to your cluster. This is used for mutual auth
        between the master and the nodes.

#. Configure kubernetes administration. At this point you should be logged in
   as root. The following will update both root and ubuntu user accounts for
   kubernetes administration.

   .. code-block:: bash

      mkdir -p $HOME/.kube
      sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
      sudo chown $(id -u):$(id -g) $HOME/.kube/config
      exit
      mkdir -p $HOME/.kube
      sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
      sudo chown $(id -u):$(id -g) $HOME/.kube/config
      cd $HOME

#. Verify kubernetes is up and running. You can monitor the services are
   running by using the following command.

   .. code-block:: bash

      kubectl get pods --all-namespaces

   You'll need to run this several times until you see several containers
   "Running"  It should look like the following:

   .. image:: images/cluster-setup-guide-kubeadmin-init-check.png

   .. note:: corends won't start until the network pod is up and running.

#. Install flannel

   .. code-block:: bash

      kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

   .. note:: You must install a *pod* network add-on so that your *pods* can
      communicate with each other. **It is necessary to do this before you try
      to deploy any applications to your cluster**, and before "coredns" will
      start up.

#. If everything installs and starts as expected you should have "coredns" and
   all services status "Running". To check the status of core services, you
   can run the following command:

   .. code-block:: bash

      kubectl get pods --all-namespaces

   The output should show all services as running.

   .. image:: images/cluster-setup-guide-kubeadmin-init-check-cluster-get-pods.png

   .. important:: Before moving to the next lab, "Setup the Nodes" wait for
      all system pods to show status “Running”.

#. Additional kubernetes status checks.

   .. code-block:: bash

      kubectl get cs

   .. image:: images/cluster-setup-guide-kubeadmin-init-check-cluster.png

   .. code-block:: bash

      kubectl cluster-info

   .. image:: images/cluster-setup-guide-kubeadmin-init-check-cluster-info.png

.. hint:: If you made a mistake and need to re-initialize the cluster run
   the following commands:

   .. code-block:: bash

      # If you followed the instructions you should be currently connected as user **ubuntu**
      # When prompted for password enter "default" without the quotes
      su -

      # This resets the master to default settings
      # You may need to run this command on the "nodes" if a fully functioning cluster is configured
      kubeadm reset --force

      # This removes the admin references to the broken cluster
      rm -rf /home/ubuntu/.kube /root/.kube