Implement custom Python packages into yocto
===========================================

Step 1 - Find package
---------------------

Firstly you should check the exact name of the Python package under this
`link`_.

.. _link: https://pypi.org/

Step 2 - Install ``pipoe``
--------------------------

The tool to create recipes is called ``pipoe``. It is available at `pypi.org`_.
To install it you can simply use ``pip`` or ``conda``.

.. code-block::

   pip install pipoe


.. _pypi.org: https://pypi.org

Step 3 - Generate custom recipe
-------------------------------

If you installed and checked the name of the package you can generate recipe by
executing

.. code-block::

   pipoe --package <package_name>


.. tip:: You can also use ``-h`` option and find out all of available
   posibilities.

Step 4 - Generate recipe for ``mfrc522``
----------------------------------------

For this use case device require ``mfrc522`` Python package. It provide
compatibility layer to handle RC-522 RFID scanner. To create custom recipe
which will install this package on system firstly you need to create folder
structure.

.. code-block::

   mkdir -p ../meta-golemos/recipes-base/python3-mfrc522/


Next, simply generate recipe with previously installed package.

.. code-block::

   pipoe --package mfrc522 --python python3 --outdir ../meta-golemos/recipes-base/python3-mfrc522


.. note:: If prompted write MIT license.


.. warning:: This tool generate more than one recipe in order to satisfy
   dependencies. In ``meta-raspberrypi`` and ``meta-python`` layers there are
   already this dependencies. Remove other recipes and change line with
   ``RDEPENDS`` in relevant file to this ``RDEPENDS_${PN} = "rpi-gpio
   python3-spidev python3-setuptools"``. You can also add this packages to base
   package group.


Step 4 - Add recipe to package group
------------------------------------

To implement this recipe in system you have to add ``python3-mfrc522`` to the
base package group in Python section.

Step 5 - Enable SPI
-------------------

To enable RFID reader you need to enable SPI communication in distribution
configuration. To do that add this line to ``golemos.conf``

.. code-block::

   ENABLE_SPI_BUS = "1"


Summary
-------

After this steps your whole layer structure should look like this.

.. code-block::

   ../meta-golemos
   ├── COPYING.MIT
   ├── README
   ├── conf
   │   ├── bblayers.conf.sample
   │   ├── conf-notes.txt
   │   ├── distro
   │   │   └── golemos.conf
   │   ├── layer.conf
   │   └── local.conf.sample
   ├── recipes-base
   │   ├── datalogger-setup-page
   │   │   └── datalogger-setup-page.bb
   │   ├── nginx
   │   │   ├── files
   │   │   │   ├── datalogger-setup.local
   │   │   │   └── datalogger.local
   │   │   └── nginx_%.bbappend
   │   ├── python3-gunicorn
   │   │   ├── files
   │   │   │   ├── datalogger_setup_page.service
   │   │   │   └── datalogger_setup_page.socket
   │   │   └── python3-gunicorn_%.bbappend
   │   └── python3-mfrc522
   │       └── python3-mfrc522_0.0.7.bb
   ├── recipes-connectivity
   │   ├── hostapd
   │   │   ├── files
   │   │   │   ├── hostapd@.service
   │   │   │   └── wlan0.conf
   │   │   └── hostapd_%.bbappend
   │   ├── kea
   │   │   ├── files
   │   │   │   ├── kea-dhcp4.conf
   │   │   │   └── kea-dhcp4.service
   │   │   └── kea_%.bbappend
   │   └── wpa-supplicant
   │       ├── files
   │       │   └── wpa_supplicant-nl80211-wlan0.conf
   │       └── wpa-supplicant_%.bbappend
   ├── recipes-core
   │   ├── images
   │   │   ├── datalogger-dev-image.bb
   │   │   ├── datalogger-extended-image.bb
   │   │   └── datalogger-image.bb
   │   ├── packagegroups
   │   │   ├── datalogger-base-packagegroup.bb
   │   │   ├── datalogger-core-packagegroup.bb
   │   │   ├── datalogger-dev-packagegroup.bb
   │   │   └── datalogger-extended-packagegroup.bb
   │   ├── systemd
   │   │   └── systemd_%.bbappend
   │   └── systemd-conf
   │       ├── files
   │       │   └── wlan.network
   │       └── systemd-conf_%.bbappend
   └── recipes-example
       └── example
           └── example_0.1.bb