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

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

Install Mesos, Marathon and Zookeeper
-------------------------------------

#. Add the mesos/marathon repo

   Run the following commands:

   .. code-block:: bash

      apt-key adv --keyserver keyserver.ubuntu.com --recv E56151BF

      cat <<EOF >> /etc/apt/sources.list.d/mesosphere.list
      deb http://repos.mesosphere.com/ubuntu $(lsb_release -cs) main
      EOF

#. Install the mesos, marathon and zookeeper packages

   .. code-block:: bash

      apt update && apt install mesos marathon zookeeperd -y

Setup Zookeeper
---------------

.. note:: ``2181`` is zookeeper's default port.

#. Setup a unique ID per zookeeper instance. Update
   ``/etc/zookeeper/conf/myid`` to ``1``, ``2`` or ``3`` depending on the
   number of master nodes.  In our case ``1``

   .. code-block:: bash

      echo 1 > /etc/zookeeper/conf/myid

#. Modify the zookeeper config file on each master

   .. code-block:: bash

      sed -i /^#server.1/s/#server.1=zookeeper1/server.1=10.2.10.21/ /etc/zookeeper/conf/zoo.cfg

Setup Mesos
-----------

#. Create mesos `ip` file /etc/mesos-master/ip

   .. code-block:: bash

      echo "10.2.10.21" > /etc/mesos-master/ip

#. Create mesos `hostname` file /etc/mesos-master/hostname (specify the IP
   address of your node)

   .. code-block:: bash

      echo "10.2.10.21" > /etc/mesos-master/hostname

#. Change the quorum value to reflect our cluster size. It should be set over
   50% of the number of master instances. In this case it should be ``1``
   because we have only one master

   .. code-block:: bash

      echo 1 > /etc/mesos-master/quorum

#. Point zookeeper to the master instance. This is done in the file
   /etc/mesos/zk

   .. code-block:: bash

      echo "zk://10.2.10.21:2181/mesos" > /etc/mesos/zk

Setup Marathon
--------------

#. First we need to specify the zookeeper masters that marathon will connect to
   (for information and things like scheduling). We can copy the previous file
   we setup for mesos:

   .. code-block:: bash

      echo "MARATHON_MASTER=`cat /etc/mesos/zk`" > /etc/default/marathon

#. We also need to have marathon store its own state in zookeper (since it
   runs on all three masters):

   .. code-block:: bash

      echo "MARATHON_ZK=zk://10.2.10.21:2181/marathon" >> /etc/default/marathon

Start your services
-------------------

#. When you install mesos, the master and slave services are enabled (called
   mesos-master and mesos-slave). Here, we want our master to focus on this
   tasks so we need to disable the slave service. Do this on *all the master*
   nodes:

   .. code-block:: bash

      systemctl stop mesos-slave
      echo manual > /etc/init/mesos-slave.override

#. We need to restart zookeeper and start mesos-master and marathon process on
   *all master* nodes:

   .. code-block:: bash

      systemctl restart zookeeper

      systemctl start mesos-master
      systemctl enable mesos-master

      systemctl start marathon

#. We can validate that it works by connecting to mesos and marathon via a
   browser. Mesos runs on port 5050 (http) and marathon runs on port 8080
   (http).

   Mesos:

   .. image:: images/setup-master-check-UI-mesos-master.png

   Marathon:

   .. image:: images/setup-master-check-UI-marathon.png

#. If you want to check whether the service started as expected, you can use
   the following commands:

   .. code-block:: bash

      systemctl status mesos-master

      systemctl status marathon

   You should see something like the following:

   Mesos:

   .. image:: images/setup-master-check-service-mesos-master.png

   Marathon:

   .. image:: images/setup-master-check-service-marathon.png

#. For more information about the marathon service, check the *about* section
   in marathon by clicking the ``?`` drop down in the upper right hand side of
   the marathon page.

   .. image:: images/setup-master-about-marathon.png

#. If multiple ``masters`` were configured for high availability you can do the
   following to test the HA of marathon:

   .. attention:: For our lab we have only one master so this step is for
      documentation purposes.

   - Figure out which mesos is running the framework marathon (based on our
     screenshot above, it is available on master1)
   - Restart this master and you should see the framework was restarted
     automatically on another host. "mesos-master1" would change to
     "mesos-master2, 3, etc."

   .. image:: images/setup-master-test-HA-marathon.png