[v6,10/10] doc: update dts setup and test suite cookbook

  Document how to configure and run DTS.
Also add documentation related to new features: SUT setup and a brief
test suite implementation cookbook.

Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
---
 doc/guides/tools/dts.rst | 165 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 163 insertions(+), 2 deletions(-)
  

Tested-by: Patrick Robb <probb@iol.unh.edu>

On Fri, Mar 3, 2023 at 5:25 AM Juraj Linkeš <juraj.linkes@pantheon.tech>
wrote:

> Document how to configure and run DTS.
> Also add documentation related to new features: SUT setup and a brief
> test suite implementation cookbook.
>
> Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> ---
>  doc/guides/tools/dts.rst | 165 ++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 163 insertions(+), 2 deletions(-)
>
> diff --git a/doc/guides/tools/dts.rst b/doc/guides/tools/dts.rst
> index daf54359ed..ebd6dceb6a 100644
> --- a/doc/guides/tools/dts.rst
> +++ b/doc/guides/tools/dts.rst
> @@ -1,5 +1,5 @@
>  ..  SPDX-License-Identifier: BSD-3-Clause
> -    Copyright(c) 2022 PANTHEON.tech s.r.o.
> +    Copyright(c) 2022-2023 PANTHEON.tech s.r.o.
>
>  DPDK Test Suite
>  ===============
> @@ -56,7 +56,7 @@ DTS runtime environment or just plain DTS environment
> are used interchangeably.
>
>
>  Setting up DTS environment
> ---------------------------
> +~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>  #. **Python Version**
>
> @@ -93,6 +93,167 @@ Setting up DTS environment
>        poetry install
>        poetry shell
>
> +#. **SSH Connection**
> +
> +   DTS uses Python pexpect for SSH connections between DTS environment
> and the other hosts.
> +   The pexpect implementation is a wrapper around the ssh command in the
> DTS environment.
> +   This means it'll use the SSH agent providing the ssh command and its
> keys.
> +
> +
> +Setting up System Under Test
> +----------------------------
> +
> +There are two areas that need to be set up on a System Under Test:
> +
> +#. **DPDK dependencies**
> +
> +   DPDK will be built and run on the SUT.
> +   Consult the Getting Started guides for the list of dependencies for
> each distribution.
> +
> +#. **Hardware dependencies**
> +
> +   Any hardware DPDK uses needs a proper driver
> +   and most OS distributions provide those, but the version may not be
> satisfactory.
> +   It's up to each user to install the driver they're interested in
> testing.
> +   The hardware also may also need firmware upgrades, which is also left
> at user discretion.
> +
> +#. **Hugepages**
> +
> +   There are two ways to configure hugepages:
> +
> +   * DTS configuration
> +
> +     You may specify the optional hugepage configuration in the DTS
> config file.
> +     If you do, DTS will take care of configuring hugepages,
> +     overwriting your current SUT hugepage configuration.
> +
> +   * System under test configuration
> +
> +     It's possible to use the hugepage configuration already present on
> the SUT.
> +     If you wish to do so, don't specify the hugepage configuration in
> the DTS config file.
> +
> +
> +Running DTS
> +-----------
> +
> +DTS needs to know which nodes to connect to and what hardware to use on
> those nodes.
> +Once that's configured, DTS needs a DPDK tarball and it's ready to run.
> +
> +Configuring DTS
> +~~~~~~~~~~~~~~~
> +
> +DTS configuration is split into nodes and executions and build targets
> within executions.
> +By default, DTS will try to use the ``dts/conf.yaml`` config file,
> +which is a template that illustrates what can be configured in DTS:
> +
> +  .. literalinclude:: ../../../dts/conf.yaml
> +     :language: yaml
> +     :start-at: executions:
> +
> +
> +The user must be root or any other user with prompt starting with ``#``.
> +The other fields are mostly self-explanatory
> +and documented in more detail in
> ``dts/framework/config/conf_yaml_schema.json``.
> +
> +DTS Execution
> +~~~~~~~~~~~~~
> +
> +DTS is run with ``main.py`` located in the ``dts`` directory after
> entering Poetry shell::
> +
> +   usage: main.py [-h] [--config-file CONFIG_FILE] [--output-dir
> OUTPUT_DIR] [-t TIMEOUT]
> +                  [-v VERBOSE] [-s SKIP_SETUP] [--tarball TARBALL]
> +                  [--compile-timeout COMPILE_TIMEOUT] [--test-cases
> TEST_CASES]
> +                  [--re-run RE_RUN]
> +
> +   Run DPDK test suites. All options may be specified with the
> environment variables provided in
> +   brackets. Command line arguments have higher priority.
> +
> +   options:
> +     -h, --help            show this help message and exit
> +     --config-file CONFIG_FILE
> +                           [DTS_CFG_FILE] configuration file that
> describes the test cases, SUTs
> +                           and targets. (default: conf.yaml)
> +     --output-dir OUTPUT_DIR, --output OUTPUT_DIR
> +                           [DTS_OUTPUT_DIR] Output directory where dts
> logs and results are
> +                           saved. (default: output)
> +     -t TIMEOUT, --timeout TIMEOUT
> +                           [DTS_TIMEOUT] The default timeout for all DTS
> operations except for
> +                           compiling DPDK. (default: 15)
> +     -v VERBOSE, --verbose VERBOSE
> +                           [DTS_VERBOSE] Set to 'Y' to enable verbose
> output, logging all
> +                           messages to the console. (default: N)
> +     -s SKIP_SETUP, --skip-setup SKIP_SETUP
> +                           [DTS_SKIP_SETUP] Set to 'Y' to skip all setup
> steps on SUT and TG
> +                           nodes. (default: N)
> +     --tarball TARBALL, --snapshot TARBALL
> +                           [DTS_DPDK_TARBALL] Path to DPDK source code
> tarball which will be
> +                           used in testing. (default: dpdk.tar.xz)
> +     --compile-timeout COMPILE_TIMEOUT
> +                           [DTS_COMPILE_TIMEOUT] The timeout for
> compiling DPDK. (default: 1200)
> +     --test-cases TEST_CASES
> +                           [DTS_TESTCASES] Comma-separated list of test
> cases to execute.
> +                           Unknown test cases will be silently ignored.
> (default: )
> +     --re-run RE_RUN, --re_run RE_RUN
> +                           [DTS_RERUN] Re-run each test case the
> specified amount of times if a
> +                           test failure occurs (default: 0)
> +
> +
> +The brackets contain the names of environment variables that set the same
> thing.
> +The minimum DTS needs is a config file and a DPDK tarball.
> +You may pass those to DTS using the command line arguments or use the
> default paths.
> +
> +
> +DTS Results
> +~~~~~~~~~~~
> +
> +Results are stored in the output dir by default
> +which be changed with the ``--output-dir`` command line argument.
> +The results contain basic statistics of passed/failed test cases and DPDK
> version.
> +
> +
> +How To Write a Test Suite
> +-------------------------
> +
> +All test suites inherit from ``TestSuite`` defined in
> ``dts/framework/test_suite.py``.
> +There are four types of methods that comprise a test suite:
> +
> +#. **Test cases**
> +
> +   | Test cases are methods that start with a particular prefix.
> +   | Functional test cases start with ``test_``, e.g.
> ``test_hello_world_single_core``.
> +   | Performance test cases start with ``test_perf_``, e.g.
> ``test_perf_nic_single_core``.
> +   | A test suite may have any number of functional and/or performance
> test cases.
> +     However, these test cases must test the same feature,
> +     following the rule of one feature = one test suite.
> +     Test cases for one feature don't need to be grouped in just one test
> suite, though.
> +     If the feature requires many testing scenarios to cover,
> +     the test cases would be better off spread over multiple test suites
> +     so that each test suite doesn't take too long to execute.
> +
> +#. **Setup and Teardown methods**
> +
> +   | There are setup and teardown methods for the whole test suite and
> each individual test case.
> +   | Methods ``set_up_suite`` and ``tear_down_suite`` will be executed
> +     before any and after all test cases have been executed, respectively.
> +   | Methods ``set_up_test_case`` and ``tear_down_test_case`` will be
> executed
> +     before and after each test case, respectively.
> +   | These methods don't need to be implemented if there's no need for
> them in a test suite.
> +     In that case, nothing will happen when they're is executed.
> +
> +#. **Test case verification**
> +
> +   Test case verification should be done with the ``verify`` method,
> which records the result.
> +   The method should be called at the end of each test case.
> +
> +#. **Other methods**
> +
> +   Of course, all test suite code should adhere to coding standards.
> +   Only the above methods will be treated specially and any other methods
> may be defined
> +   (which should be mostly private methods needed by each particular test
> suite).
> +   Any specific features (such as NIC configuration) required by a test
> suite
> +   should be implemented in the ``SutNode`` class (and the underlying
> classes that ``SutNode`` uses)
> +   and used by the test suite via the ``sut_node`` field.
> +
>
>  DTS Developer Tools
>  -------------------
> --
> 2.30.2
>
>