.. index:: first devices

.. _first_devices:

Adding your first devices
#########################

.. caution:: **Do not rush**. **Always** start with QEMU testing, then add a
   real device which is well supported by LAVA. Purchase and integrate one of
   the :ref:`standard known devices <standard_known_devices>`. Take time to
   learn what is required to automate a :term:`DUT`. Avoid rushing into adding
   your own new :term:`device type`. When you have a LAVA instance which has
   successfully run a few dozen test jobs using ``QEMU`` and a standard known
   device, then consider how to :ref:`integrate a new device-type into LAVA
   <adding_new_device_types>`.

Requirements
************

You need to be familiar with these sections:

#. :ref:`installation`
#. :ref:`Creating a pipeline worker <setting_up_pipeline_instance>`.
#. :ref:`adding_pipeline_devices_to_worker`
#. :ref:`create_superuser`
#. :ref:`logging_in` (as superuser)
#. :ref:`device_types` and :ref:`device_type_elements`

.. _django_admin_interface:

Django administration interface
*******************************

The django admin interface is a core component of the django framework.
Elements can be added for particular implementations but, fundamentally, the
operation of the interface is the same as other django sites. The appearance of
the menu is determined by the version of django installed on your system. The
style changed substantially in django 1.9, so images of the interface itself
are not included here.

Changes within the administration interface and changes made as a superuser
through the UI are tracked through the **History** elements of objects in the
database. When viewing a specific element (for example a single Test Job or a
single Device), click on the **History** link to view all changes relating to
that element. There is also a link back to the UI view of the same element.

.. note:: the organisation, layout and content of the django administration
   interface is subject to change with upgrades to django itself and these
   changes are outside the control of LAVA.

.. _django_admin_interface_sites:

Administative interface site links
==================================

The django administrative interface offers links back to your LAVA instance
*if* the ``Sites`` element is modified. (The default django value is
``example.com``.) Navigate to the ``Sites`` element in the administrative
interface and modify the domain name and display name. Once complete, links
like ``View site`` and the ``View on site`` button on certain pages of the
interface will link to the correct location in your LAVA instance.

Start with a known device type
******************************

It is tempting to jump straight in with your one-off special device which
nobody else has managed to automate yet but a fresh install **needs** to be
tested with a known working configuration. Setting up known working devices and
learning how to modify the :ref:`first job <first_job_definition>` is essential
to deciding how to best configure a new device. It is also **recommended** to
setup another known device type which is similar to the device you want to add
as there are different steps required for certain types of device.

This first QEMU device can be configured on the existing worker which is always
available on the master. Subsequent devices can be added to other workers and
devices can be shuffled between workers, subject to limitations of physical
connections.

QEMU
====

QEMU is always recommended as the first device to be set up on any LAVA
instance for a few reasons:

#. QEMU requires no external hardware or software configuration (until a
   network bridge becomes desirable)

#. QEMU requires only a minimal :term:`device dictionary`.

#. Test images for use with QEMU are readily available and relatively easy to
   modify.

.. seealso:: :ref:`creating_gold_standard_files` and
   :ref:`create_device_database`.

.. index:: add-device-type, adding a device type

.. _create_device_type_database:

Create a Device Type
--------------------

Prior to adding any devices, admins should add suitable :term:`device types
<device type>` to the database. The device type name should match a jinja2
template file in::

 /etc/lava-server/dispatcher-config/device-types/

If an existing template does not exist, a new template will need to be created.

.. seealso:: :ref:`device_types`

You can then either use the :ref:`web admin interface <django_admin_interface>`
or the ``lava-server`` command line to add device types.

**Using the admin interface**

In order to use the web admin interface, log in to the LAVA instance and click
on your username to see the Profile menu.

.. image:: images/profile-menu.png

The django administrative interface is accessed from the ``Administration``
link in the profile menu.

#. Scroll down to the group labelled ``LAVA_SCHEDULER_APP``.
#. Click on ``Device types``

Just before you add the device type, take a look at the available
:ref:`elements of a device type <device_type_elements>`:

* Name
* Has health check
* Display
* Owners only
* Health check frequency
* Architecture name
* Processor name
* CPU model name
* List of cores
* Bit count

The only value needed for the QEMU device type is the **Name**, just check that
**Display** is the default: enabled. Now Save.

**Using the command line**

On the command line, you can add device types (for instance QEMU and panda)
using::

  lava-server manage device-types add qemu
  lava-server manage device-types add panda

It's also possible to add all known device types at the same time with:

.. code-block:: none

  lava-server manage device-types add '*'

Descriptive fields like ``Architecture name``, ``Processor name``, ``CPU model
name``, ``List of cores`` and ``Bit count`` cannot be set on the command line.

Using the command line interface it's also possible to list all known device
types:

.. code-block:: none

  lava-server manage device-types list --all

.. index:: add-device, adding a device, create a device in the database

.. _create_device_database:

Create a device in the database
-------------------------------

**Using the admin interface**

* Navigate back to ``LAVA_SCHEDULER_APP`` and select ``Devices`` and
  ``Add Device``.
* Select the QEMU device type from the list.
* Give your device a name
* Select the worker from the list.
* Set the Device owner (typically one of the superusers).
* Your first device should be public.
* Ensure that the device is enabled as a ``Pipeline device``.

**Using the command line**

Using the command line interface it's also possible to list all known device
types:

.. code-block:: none

  lava-server manage device-types list -a

On the command line, you can add device types (for instance a QEMU type device
with a hostname ``qemu01``) using:

.. code-block:: none

  lava-server manage devices add --device-type qemu --worker <worker> qemu01

If a :term:`health check` is already defined, the device will start
running a health check immediately. Alternatively, specify the
``offline`` option to set the initial state:

.. code-block:: none

  lava-server manage devices add --offline --device-type qemu --worker <worker> qemu01

It is also possible to copy an existing device as a new device with a new hostname.

.. code-block:: none

  # copy existing qemu01 to a new qem02
  lava-server manage devices copy qemu01 qemu02 --worker <worker> --offline

See ``lava-server manage help devices`` for more options.

Adding a dictionary to the first QEMU device
--------------------------------------------

For the first device, a simple :term:`device dictionary` can be used
to provide the device-specific details on top of the template:

.. code-block:: jinja

  {% extends 'qemu.jinja2' %}
  {% set mac_addr = '52:54:00:12:34:59' %}
  {% set memory = '1024' %}

* The device dictionary **must** ``extend`` an existing template.

* The architecture (``arch`` value) is not set in this device dictionary. This
  allows this device to run test jobs using files for any architecture
  supported by QEMU.

  .. seealso:: :ref:`overriding_device_configuration`

* The MAC address needs to differ for each device of this type across all
  instances on the same subnet.

* The available memory for the virtual machine is set in megabytes. This can be
  changed later to balance the requirements of test jobs with performance on
  the worker.

* Line ordering within the device dictionary is irrelevant, although it is
  common to put the ``extends`` line first when storing the dictionary as a
  file.

The template itself lives in::

 /etc/lava-server/dispatcher-config/device-types/qemu.jinja2

This dictionary does not include a setting to use a ``tap`` device which means
that this device would not support a hacking session inside the virtual
machine. Setting up a bridge is out of scope for this documentation.

.. seealso:: :ref:`create_device_dictionary` to export and modify a device
   dictionary, :ref:`updating_device_dictionary` to import a device dictionary
   into the database for use with a new or existing device,
   :ref:`checking_templates` for help with types of devices other than QEMU and
   :ref:`device_type_templates` for help with how the device dictionary works
   with the device-type templates.

Once updated, the device dictionary is added to the Device view in the
administrative interface under the Advanced Properties section at the base of
the page.

.. index:: adding devices of known types

.. _adding_known_devices:

Adding other devices of known device-types
******************************************

The core principles remain the same as for QEMU, the main differences are in
the way that the device dictionary is needed to provide a wider range of
settings covering power control, serial connections, network details and other
values.

.. seealso:: :ref:`health_checks` - each time a new device type is added to an
   instance, a health check test job needs to be defined.

.. seealso:: :ref:`growing_your_lab`, including :ref:`lab_scaling`.

Check existing instances
========================

Templates usually exist for known device types because an existing instance is
using the template. Often, that instance will be Linaro's central validation
lab in Cambridge which is accessible via https://validation.linaro.org/ .

The contents of the device dictionary for particular devices are visible to
anyone with access to that device type, using the device detail page. Details
of the jinja2 files used to update the device dictionary on Linaro instances is
also held in git::

 https://git.linaro.org/lava/lava-lab.git

The structure of the device dictionary files will be similar for each device of
the same type but the values will change. An example for a beaglebone-black
device looks like:

.. code-block:: jinja

 {% extends 'beaglebone-black.jinja2' %}
 {% set connection_command = 'telnet localhost 7101' %}
 {% set hard_reset_command = '/usr/local/lab-scripts/snmp_pdu_control --hostname pdu15 --command reboot --port 11' %}
 {% set power_off_command = '/usr/local/lab-scripts/snmp_pdu_control --hostname pdu15 --command off --port 11' %}
 {% set power_on_command = '/usr/local/lab-scripts/snmp_pdu_control --hostname pdu15 --command on --port 11' %}

https://git.linaro.org/lava/lava-lab.git/tree/staging.validation.linaro.org/master-configs/staging-master.lavalab/lava-server/dispatcher-config/devices/staging-black01.jinja2

.. note:: It is recommended to keep the device dictionary jinja files under
   version control. The templates are configuration files, so if you modify the
   default templates, those need to be under version control as well.
