Getting Started¶
This section of the manual contains introductory tutorials for installing labgrid, running your first test and setting up the distributed infrastructure. For an overview about the basic design and components of labgrid, read the Overview first.
Installation¶
Depending on your distribution you need some dependencies. On Debian stretch and buster these usually are:
$ apt-get install python3 python3-virtualenv python3-pip python3-setuptools virtualenv
In many cases, the easiest way is to install labgrid into a virtualenv:
$ virtualenv -p python3 labgrid-venv
$ source labgrid-venv/bin/activate
Start installing labgrid by cloning the repository and installing the requirements from the requirements.txt file:
$ git clone https://github.com/labgrid-project/labgrid
$ cd labgrid && pip install -r requirements.txt
$ python3 setup.py install
Note
Previous documentation recommended the installation as via pip (pip3 install labgrid). This lead to broken installations due to unexpected incompatibilities with new releases of the dependencies. Consequently we now recommend using pinned versions from the requirements.txt file for most use cases.
labgrid also supports the installation as a library via pip, but we only test against library versions specified in the requirements.txt file. Thus when installing directly from pip you have to test compatibility yourself.
Note
If you are installing via pip and intend to use Serial over IP (RFC2217), it is highly recommended to uninstall pyserial after installation and replace it with the pyserial version from the labgrid project:
$ pip uninstall pyserial $ pip install https://github.com/labgrid-project/pyserial/archive/v3.4.0.1.zip#egg=pyserial
This pyserial version has two fixes for an Issue we found with Serial over IP multiplexers. Additionally it reduces the Serial over IP traffic considerably since the port is not reconfigured when labgrid changes the timeout (which is done inside the library a lot).
Test your installation by running:
$ labgrid-client --help
usage: labgrid-client [-h] [-x URL] [-c CONFIG] [-p PLACE] [-d] COMMAND ...
...
If the help for labgrid-client does not show up, open an Issue. If everything was successful so far, proceed to the next section:
Optional Requirements¶
labgrid provides optional features which are not included in the default requirements.txt. The tested library version for each feature is included in a seperate requirements file. An example for snmp support is:
$ pip install -r snmp-requirements.txt
Onewire¶
Onewire support requires the libow library with headers, installable on debian via the libow-dev package. Use the onewire-requirements.txt file to install the correct onewire library version in addition to the normal installation.
SNMP¶
SNMP support requires to additional packages, pysnmp and pysnmpmibs. They are included in the snmp-requirements.txt file.
Modbus¶
Modbus support requires an additional package pyModbusTCP. It is included in the modbus-requirements.txt file.
Running Your First Test¶
Start by copying the initial example:
$ mkdir ../first_test/
$ cp examples/shell/* ../first_test/
$ cd ../first_test/
Connect your embedded board (raspberry pi, riotboard, …) to your computer and
adjust the port
parameter of the RawSerialPort
resource and username
and password
of the ShellDriver driver in local.yaml
:
targets:
main:
resources:
RawSerialPort:
port: "/dev/ttyUSB0"
drivers:
ManualPowerDriver:
name: "example"
SerialDriver: {}
ShellDriver:
prompt: 'root@\w+:[^ ]+ '
login_prompt: ' login: '
username: 'root'
You can check which device name gets assigned to your USB-Serial converter by
unplugging the converter, running dmesg -w
and plugging it back in. Boot up
your board (manually) and run your first test:
$ pytest --lg-env local.yaml test_shell.py
It should return successfully, in case it does not, open an Issue.
If you want to build documentation you need some more dependencies:
$ pip3 install -r doc-requirements.txt
The documentation is inside doc/
. HTML-Documentation is build using:
$ cd doc/
$ make html
The HTML documentation is written to doc/.build/html/
.
Setting Up the Distributed Infrastructure¶
The labgrid distributed infrastructure consists of three components:
The system needs at least one coordinator and exporter, these can run on the same machine. The client is used to access functionality provided by an exporter. Over the course of this tutorial we will set up a coordinator and exporter, and learn how to access the exporter via the client.
Coordinator¶
To start the coordinator, we will download the labgrid repository, create an extra virtualenv and install the dependencies via the requirements file.
$ git clone https://github.com/labgrid-project/labgrid
$ cd labgrid && virtualenv -p python3 crossbar_venv
$ source crossbar_venv/bin/activate
$ sudo apt install libsnappy-dev
$ pip install -r crossbar-requirements.txt
$ python setup.py install
All necessary dependencies should be installed now, we can start the coordinator
by running crossbar start
inside of the repository.
Note
This is possible because the labgrid repository contains the crossbar
configuration the coordinator in the .crossbar
folder.
crossbar is a network messaging framework for building distributed
applications, which labgrid plugs into.
Note
For long running deployments, you should copy and customize the
.crossbar/config.yaml
file for your use case. This includes
setting a different workdir
and may include changing the running
port.
Exporter¶
The exporter needs a configuration file written in YAML syntax, listing the resources to be exported from the local machine. The config file contains one or more named resource groups. Each group contains one or more resource declarations and optionally a location string (see the configuration reference for details).
For example, to export a USBSerialPort
with ID_SERIAL_SHORT
of
ID23421JLK
, the group name example-group and the location
example-location:
example-group:
location: example-location
USBSerialPort:
ID_SERIAL_SHORT: ID23421JLK
Note
Use labgrid-suggest
to generate the YAML snippets for most
exportable resources.
The exporter can now be started by running:
$ labgrid-exporter configuration.yaml
Additional groups and resources can be added:
example-group:
location: example-location
USBSerialPort:
match:
'ID_SERIAL_SHORT': 'P-00-00682'
speed: 115200
NetworkPowerPort:
model: netio
host: netio1
index: 3
example-group-2:
USBSerialPort:
ID_SERIAL_SHORT: KSLAH2341J
Restart the exporter to activate the new configuration.
Attention
The ManagedFile will create temporary uploads in the exporters
/var/cache/labgrid
directory. This directory needs to be created manually
and should allow write access for users. The /contrib
directory in the
labgrid-project contains a tmpfiles configuration example to automatically
create and clean the directory.
It is also highly recommended to enable fs.protected_regular=1
and
fs.protected_fifos=1
for kernels>=4.19, to protect the users from opening
files not owned by them in world writeable sticky directories.
For more information see this kernel commit.
Client¶
Finally we can test the client functionality, run:
$ labgrid-client resources
kiwi/example-group/NetworkPowerPort
kiwi/example-group/NetworkSerialPort
kiwi/example-group-2/NetworkSerialPort
You can see the available resources listed by the coordinator. The groups example-group and example-group-2 should be available there.
To show more details on the exported resources, use -v
(or -vv
):
$ labgrid-client -v resources
Exporter 'kiwi':
Group 'example-group' (kiwi/example-group/*):
Resource 'NetworkPowerPort' (kiwi/example-group/NetworkPowerPort[/NetworkPowerPort]):
{'acquired': None,
'avail': True,
'cls': 'NetworkPowerPort',
'params': {'host': 'netio1', 'index': 3, 'model': 'netio'}}
...
You can now add a place with:
$ labgrid-client --place example-place create
And add resources to this place (-p
is short for --place
):
$ labgrid-client -p example-place add-match */example-group/*
Which adds the previously defined resource from the exporter to the place. To interact with this place, it needs to be acquired first, this is done by
$ labgrid-client -p example-place acquire
Now we can connect to the serial console:
$ labgrid-client -p example-place console
Note
Using remote connection requires microcom
installed on the host
where the labgrid-client is called.
See Remote Access for some more advanced features. For a complete reference have a look at the labgrid-client(1) man page.
udev Matching¶
labgrid allows the exporter (or the client-side environment) to match resources
via udev rules.
The udev resources become available to the test/exporter as soon es they are
plugged into the computer, e.g. allowing an exporter to export all USB ports on
a specific hub and making a NetworkSerialPort
available as soon as it is
plugged into one of the hub’s ports.
labgrid also provides a small utility called labgrid-suggest
which will
output the proper YAML formatted snippets for you.
The information udev has on a device can be viewed by executing:
$ udevadm info /dev/ttyUSB0
...
E: ID_MODEL_FROM_DATABASE=CP210x UART Bridge / myAVR mySmartUSB light
E: ID_MODEL_ID=ea60
E: ID_PATH=pci-0000:00:14.0-usb-0:5:1.0
E: ID_PATH_TAG=pci-0000_00_14_0-usb-0_5_1_0
E: ID_REVISION=0100
E: ID_SERIAL=Silicon_Labs_CP2102_USB_to_UART_Bridge_Controller_P-00-00682
E: ID_SERIAL_SHORT=P-00-00682
E: ID_TYPE=generic
...
In this case the device has an ID_SERIAL_SHORT
key with a unique ID embedded
in the USB-serial converter.
The resource match configuration for this USB serial converter is:
USBSerialPort:
match:
'ID_SERIAL_SHORT': 'P-00-00682'
This section can now be added under the resource key in an environment configuration or under its own entry in an exporter configuration file.
As the USB bus number can change depending on the kernel driver initialization
order, it is better to use the @ID_PATH
instead of @sys_name
for USB
devices.
In the default udev configuration, the path is not available for all USB
devices, but that can be changed by creating a udev rules file:
SUBSYSTEMS=="usb", IMPORT{builtin}="path_id"
Using a Strategy¶
Strategies allow the labgrid library to automatically bring the board into a defined state, e.g. boot through the bootloader into the Linux kernel and log in to a shell. They have a few requirements:
A driver implementing the
PowerProtocol
, if no controllable infrastructure is available aManualPowerDriver
can be used.A driver implementing the
LinuxBootProtocol
, usually a specific driver for the board’s bootloaderA driver implementing the
CommandProtocol
, usually aShellDriver
with aSerialDriver
below it.
labgrid ships with two builtin strategies, BareboxStrategy
and
UBootStrategy
. These can be used as a reference example for simple
strategies, more complex tests usually require the implementation of your own
strategies.
To use a strategy, add it and its dependencies to your configuration YAML,
retrieve it in your test and call the transition(status)
function.
>>> strategy = target.get_driver(strategy)
>>> strategy.transition("barebox")
An example using the pytest plugin is provided under examples/strategy.