selftests: Introduce tc testsuite

__pycache__/

tdc - Linux Traffic Control (tc) unit testing suite

Author: Lucas Bates - lucasb@mojatatu.com

tdc is a Python script to load tc unit tests from a separate JSON file and

execute them inside a network namespace dedicated to the task.

REQUIREMENTS

------------

*  Minimum Python version of 3.4. Earlier 3.X versions may work but are not

   guaranteed.

*  The kernel must have network namespace support

*   The kernel must have veth support available, as a veth pair is created

   prior to running the tests.

*  All tc-related features must be built in or available as modules.

   To check what is required in current setup run:

   ./tdc.py -c

   Note:

   In the current release, tdc run will abort due to a failure in setup or

   teardown commands - which includes not being able to run a test simply

   because the kernel did not support a specific feature. (This will be

   handled in a future version - the current workaround is to run the tests

   on specific test categories that your kernel supports)

BEFORE YOU RUN

--------------

The path to the tc executable that will be most commonly tested can be defined

in the tdc_config.py file. Find the 'TC' entry in the NAMES dictionary and

define the path.

If you need to test a different tc executable on the fly, you can do so by

using the -p option when running tdc:

	./tdc.py -p /path/to/tc

RUNNING TDC

-----------

To use tdc, root privileges are required. tdc will not run otherwise.

All tests are executed inside a network namespace to prevent conflicts

within the host.

Running tdc without any arguments will run all tests. Refer to the section

on command line arguments for more information, or run:

	./tdc.py -h

tdc will list the test names as they are being run, and print a summary in

TAP (Test Anything Protocol) format when they are done. If tests fail,

output captured from the failing test will be printed immediately following

the failed test in the TAP output.

USER-DEFINED CONSTANTS

----------------------

The tdc_config.py file contains multiple values that can be altered to suit

your needs. Any value in the NAMES dictionary can be altered without affecting

the tests to be run. These values are used in the tc commands that will be

executed as part of the test. More will be added as test cases require.

Example:

	$TC qdisc add dev $DEV1 ingress

COMMAND LINE ARGUMENTS

----------------------

Run tdc.py -h to see the full list of available arguments.

-p PATH           Specify the tc executable located at PATH to be used on this

                  test run

-c                Show the available test case categories in this test file

-c CATEGORY       Run only tests that belong to CATEGORY

-f FILE           Read test cases from the JSON file named FILE

-l [CATEGORY]     List all test cases in the JSON file. If CATEGORY is

                  specified, list test cases matching that category.

-s ID             Show the test case matching ID

-e ID             Execute the test case identified by ID

-i                Generate unique ID numbers for test cases with no existing

                  ID number

ACKNOWLEDGEMENTS

----------------

Thanks to:

Jamal Hadi Salim, for providing valuable test cases

Keara Leibovitz, who wrote the CLI test driver that I used as a base for the

   first version of the tc testing suite. This work was presented at

   Netdev 1.2 Tokyo in October 2016.

Samir Hussain, for providing help while I dove into Python for the first time

    and being a second eye for this code.

tc Testing Suite To-Do list:

- Determine what tc features are supported in the kernel. If features are not

  present, prevent the related categories from running.

- Add support for multiple versions of tc to run successively

- Improve error messages when tdc aborts its run

- Allow tdc to write its results to file

tdc - Adding test cases for tdc

Author: Lucas Bates - lucasb@mojatatu.com

ADDING TEST CASES

-----------------

User-defined tests should be added by defining a separate JSON file.  This

will help prevent conflicts when updating the repository. Refer to

template.json for the required JSON format for test cases.

Include the 'id' field, but do not assign a value. Running tdc with the -i

option will generate a unique ID for that test case.

tdc will recursively search the 'tc' subdirectory for .json files.  Any

test case files you create in these directories will automatically be included.

If you wish to store your custom test cases elsewhere, be sure to run tdc

with the -f argument and the path to your file.

Be aware of required escape characters in the JSON data - particularly when

defining the match pattern. Refer to the tctests.json file for examples when

in doubt.

TEST CASE STRUCTURE

-------------------

Each test case has required data:

id:           A unique alphanumeric value to identify a particular test case

name:         Descriptive name that explains the command under test

category:     A list of single-word descriptions covering what the command

              under test is testing. Example: filter, actions, u32, gact, etc.

setup:        The list of commands required to ensure the command under test

              succeeds. For example: if testing a filter, the command to create

              the qdisc would appear here.

cmdUnderTest: The tc command being tested itself.

expExitCode:  The code returned by the command under test upon its termination.

              tdc will compare this value against the actual returned value.

verifyCmd:    The tc command to be run to verify successful execution.

              For example: if the command under test creates a gact action,

              verifyCmd should be "$TC actions show action gact"

matchPattern: A regular expression to be applied against the output of the

              verifyCmd to prove the command under test succeeded. This pattern

              should be as specific as possible so that a false positive is not

              matched.

matchCount:   How many times the regex in matchPattern should match. A value

              of 0 is acceptable.

teardown:     The list of commands to clean up after the test is completed.

              The environment should be returned to the same state as when

              this test was started: qdiscs deleted, actions flushed, etc.

SETUP/TEARDOWN ERRORS

---------------------

If an error is detected during the setup/teardown process, execution of the

tests will immediately stop with an error message and the namespace in which

the tests are run will be destroyed. This is to prevent inaccurate results

in the test cases.

Repeated failures of the setup/teardown may indicate a problem with the test

case, or possibly even a bug in one of the commands that are not being tested.

It's possible to include acceptable exit codes with the setup/teardown command

so that it doesn't halt the script for an error that doesn't matter. Turn the

individual command into a list, with the command being first, followed by all

acceptable exit codes for the command.

[

    {

        "id": "",

        "name": "",

        "category": [

            "",

            ""

        ],

        "setup": [

            ""

        ],

        "cmdUnderTest": "",

        "expExitCode": "",

        "verifyCmd": "",

        "matchPattern": "",

        "matchCount": "",

        "teardown": [

            ""

        ]

    },

    {

        "id": "",

        "name": "",

        "category": [

            "",

            ""

        ],

        "setup": [

            ""

        ],

        "cmdUnderTest": "",

        "expExitCode": "",

        "verifyCmd": "",

        "matchPattern": "",

        "matchCount": "",

        "teardown": [

            ""

        ]

    }

]