14. DPDK Test Suite

The DPDK Test Suite, abbreviated DTS, is a Python test framework with test suites implementing functional and performance tests used to test DPDK.

14.1. DTS Terminology

DTS node: A generic description of any host/server DTS connects to.
DTS runtime environment: An environment containing Python with packages needed to run DTS.
DTS runtime environment node: A node where at least one DTS runtime environment is present. This is the node where we run DTS and from which DTS connects to other nodes.
System under test: An SUT is the combination of DPDK and the hardware we’re testing in conjunction with DPDK (NICs, crypto and other devices).
System under test node: A node where at least one SUT is present.
Traffic generator: A TG is either software or hardware capable of sending packets.
Traffic generator node: A node where at least one TG is present. In case of hardware traffic generators, the TG and the node are literally the same.

In most cases, interchangeably referring to a runtime environment, SUT, TG or the node they’re running on (e.g. using SUT and SUT node interchangeably) doesn’t cause confusion. There could theoretically be more than of these running on the same node and in that case it’s useful to have stricter definitions. An example would be two different traffic generators (such as Trex and Scapy) running on the same node. A different example would be a node containing both a DTS runtime environment and a traffic generator, in which case it’s both a DTS runtime environment node and a TG node.

14.2. DTS Environment

DTS is written entirely in Python using a variety of dependencies. DTS uses Poetry as its Python dependency management. Python build/development and runtime environments are the same and DTS development environment, DTS runtime environment or just plain DTS environment are used interchangeably.

14.3. Setting up DTS environment

Python Version

The Python Version required by DTS is specified in dts/pyproject.toml in the [tool.poetry.dependencies] section:
```
[tool.poetry.dependencies]
python = "^3.10"
```
The Python dependency manager DTS uses, Poetry, doesn’t install Python, so you may need to satisfy this requirement by other means if your Python is not up-to-date. A tool such as Pyenv is a good way to get Python, though not the only one.
Poetry

The typical style of python dependency management, pip with requirements.txt, has a few issues. The advantages of Poetry include specifying what Python version is required and forcing you to specify versions, enforced by a lockfile, both of which help prevent broken dependencies. Another benefit is the usage of pyproject.toml, which has become the standard config file for python projects, improving project organization. To install Poetry, visit their doc pages.
Getting a Poetry shell

Once you have Poetry along with the proper Python version all set up, it’s just a matter of installing dependencies via Poetry and using the virtual environment Poetry provides:
```
poetry install
poetry shell
```

14.4. DTS Developer Tools

There are three tools used in DTS to help with code checking, style and formatting:

isort

Alphabetically sorts python imports within blocks.
black

Does most of the actual formatting (whitespaces, comments, line length etc.) and works similarly to clang-format.
pylama

Runs a collection of python linters and aggregates output. It will run these tools over the repository:
```
linters = "pep8,pylint,mccabe,mypy,pycodestyle,pyflakes"
```

These three tools are all used in devtools/dts-check-format.sh, the DTS code check and format script. Refer to the script for usage: devtools/dts-check-format.sh -h.