Updating the Software
=====================

Whenever the upstream repository is updated and you would like to update to the
latest, you must do the following steps:

1. Update the software on the processing computer.
2. Rebuild the compiled components on the processing computer.
3. Restart all the server processes on the processing computer.
4. Update the software on the Microzed.
5. Rebuild the compiled components on the Microzed.
6. Restart all the server processes on the Microzed


Updating the Processing Computer
--------------------------------

To actually do these steps, you can run the following commands.  First, on the
processing computer in a terminal, ``cd`` into the software directory (e.g.
``/home/username/repo_name/sw``) and run the following commands

.. code-block:: bash

   git tag known-working-$(date +%Y-%m-%d)  #optionally, make a tag of the current revision
   git reset --hard  # This overwrites all your local changes!
   git pull origin master
   make  # this rebuilds all compiled components.

Updating the Microzed
---------------------

.. Important::

    The way the system is normally operated, the Microzed cannot access the
    internet without cooperation  from the processing computer.  There is a
    script located at ``/path/to/repository/sw/scripts/start-iptables`` that
    allows the Microzed to access the internet via the processing computer.
    That script must be run for the following steps to work.  It takes two
    arguments: the external interface (the one connected to the internet) and
    the Microzed interface.  It should be called like this:

    .. code-block:: bash

        /path/to/start-iptables enp3s0 enp4s0

    Note that the above names ``enp3s0`` and ``enp4s0`` may not be the correct
    names for your setup; check the output of ``ifconfig`` to determine which
    interface is facing the internet and which one is facing the Microzed.  By
    default, the interface connected to the Microzed has an IP address of
    192.168.1.10.

Updating the Microzed is a similar process to updating the processing computer.
First, from a terminal on the processing computer, execute the following
commands:

.. code-block:: bash

   ssh microzed
   cd ~/wni/sw
   git tag known-working-$(date +%Y-%m-%d)  #optionally, make a tag of the current revision
   git reset --hard  # This overwrites all your local changes!
   git pull
   make  # this rebuilds all compiled components

Restarting Daemons
------------------

The system relies on several long-running processes.  The above steps updated
the source code, but the  running processes are still using the old code and
need to be restarted.  The simplest way is to reboot the system.