Lava-Test Test Definition 1.0

The lava_test_shell action provides a way to employ a black-box style testing appoach with the target device. It does this by deploying an overlay to the target device; it requires a POSIX system to be running on the target. The test definition format is designed to be flexible, allowing many options on how to do things.

Quick start to Test Definition 1.0

A minimal test definition looks like this:

metadata:
  name: passfail
  format: "Lava-Test-Shell Test Definition 1.0"
  description: "A simple passfail test for demo."

run:
  steps:
    - lava-test-case test-1 --result pass
    - lava-test-case test-2 --result fail

Only the mandatory metadata parameters have been included (name, format, description).

Versioned test definitions

If your test definition is not part of a git or bzr repository then it is must include a version parameter in the metadata section like in the following example.

metadata:
  name: passfail
  format: "Lava-Test-Shell Test Definition 1.0"
  description: "A simple passfail test for demo."
  version: "1.0"

How a lava test shell is run

A lava-test-shell is run by:

  • building the test definition into a shell script.

    Note

    This shell script will include set -e, so a failing step will abort the entire test run. If you need to specify a step that might fail, finish the command with || true to make that failure not abort the test run.

  • copying an overlay onto the device. The overlay containins both the test script and the rest of the LAVA Test Helpers. and setup code to run the test script when the device boots

  • booting the device and letting the test run

  • retrieving the output from the device and turning it into a test result

  • run subsequent test definitions, if any.

Writing a test for lava-test-shell

For the majority of cases, the above approach is the easiest thing to do: write shell code that outputs “test-case-id: result” for each test case you are interested in. See the Test Developer Guide:

Warning

Older support for parse patterns and fixup dictionaries is deprecated because the support has proven too difficult to use and very hard to debug. The syntax is Python but converted through YAML and the scope is global. The support remains only for compatibility with existing Lava Test Shell Definitions. In future, any desired parsing should be moved into a custom script contained within the test definition repository. This script can simply call lava-test-case directly with the relevant options once the data is parsed. This has the advantage that the log output from LAVA can be tested directly as input for the script.

When a test runs, $PATH is arranged so that some LAVA-specific utilities are available:

See also

MultiNode API

lava-test-case

lava-test-case records the results of a single test case. For example:

steps:
  - "lava-test-case simpletestcase --result pass"
  - "lava-test-case fail-test --shell false"

It has two forms. One takes arguments to describe the outcome of the test case. The other takes the shell command to run, and the exit code of this shell command is used to produce the test result.

Both forms take the name of the testcase as the first argument.

Specifying results directly

The first form takes these additional arguments:

  • --result $RESULT: $RESULT should be one of pass/fail/skip/unknown
  • --measurement $MEASUREMENT: A numerical measurement associated with the test result
  • --units $UNITS: The units of $MEASUREMENT

--result must always be specified. For example:

run:
  steps:
    - "lava-test-case simpletestcase --result pass"
    - "lava-test-case bottle-count --result pass --measurement 99 --units bottles"

If --measurement is used, --units must also be specified, even if the unit is just a count.

The most useful way to produce output for lava-test-case result is Writing custom scripts to support tests which allow preparation of LAVA results from other sources, complete with measurements. This involves calling lava-test-case from scripts executed by the YAML file:

#!/usr/bin/env python

from subprocess import call


def test_case():
    """
    Calculate something based on a test
    and return the data
    """
    return {"name": "test-rate", "result": "pass",
        "units": "Mb/s", "measurement": 4.23}


def main():
    data = test_case()
    call(
        ['lava-test-case',
         data['name'],
         '--result', data['result'],
         '--measurement', data['measurement'],
         '--units', data['units']])
    return 0

if __name__ == '__main__':
    main()

The custom scripts themselves can be called from a lava-test-case using the --shell command to test whether failures from the tests caused a subsequent failure in the custom script.

Using the exit status of a command

The second form of lava-test-case is indicated by the --shell argument, for example:

run:
  steps:
    - "lava-test-case fail-test --shell false"
    - "lava-test-case pass-test --shell true"

The result of a shell call will only be recorded as a pass or fail, dependent on the exit code of the command.

Using parameters in the job to update the definition

Parameters used in the test definition YAML can be controlled from the YAML job file. See the following YAML test definition for ean example of how it works.

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metadata:
    format: Lava-Test Test Definition 1.0
    name: params-test
    description: "test commands for Linux POSIX images with params"
    version: "1.0"
    maintainer:
        - neil.williams@linaro.org

params:
    VARIABLE_NAME_1: value_1
    VARIABLE_NAME_2: value_2

run:
    steps:
        - lava-test-case test3 --result pass
        - lava-test-case test4 --result fail
        - lava-test-case test5 --result pass --measurement 99 --units bottles
        - lava-test-case test6 --result fail --measurement 0 --units mugs
        - echo $VARIABLE_NAME_1
        - echo $VARIABLE_NAME_2
        - echo $SPACED_VAR
        - echo $PUB_KEY

Download or view params.yaml: examples/test-definitions/params.yaml

This Lava-Test Test Definition 1.0 can be used in a simple QEMU test job:

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      username: root

- test:
    timeout:
      minutes: 5
    definitions:
    - repository: https://git.lavasoftware.org/lava/functional-tests.git
      from: git
      path: posix/parameters.yaml
      name: parse-params
      parameters:
        VARIABLE_NAME_1: "first variable value"

Download or view the test job: examples/test-jobs/qemu-stretch-params.yaml

lava-background-process-start

This starts a process in the background, for example:

steps:
  - lava-background-process-start MEM --cmd "free -m | grep Mem | awk '{print $3}' >> /tmp/memusage"
  - lava-background-process-start CPU --cmd "grep 'cpu ' /proc/stat"
  - uname -a
  - lava-background-process-stop CPU
  - lava-background-process-stop MEM --attach /tmp/memusage text/plain --attach /proc/meminfo application/octet-stream

The arguments are:

  1. The name that is used to identify the process later in lava-background-process-stop
  2. The command line for the process to be run in the background

See Recording test case data.

lava-background-process-stop

This stops a process previously started in the background using lava-background-process-start. The user can attach files to the test run if there is a need.

For example:

steps:
  - lava-background-process-start MEM --cmd "free -m | grep Mem | awk '{print $3}' >> /tmp/memusage"
  - lava-background-process-start CPU --cmd "grep 'cpu ' /proc/stat"
  - uname -a
  - lava-background-process-stop CPU
  - lava-background-process-stop MEM --attach /tmp/memusage text/plain --attach /proc/meminfo application/octet-stream

The arguments are:

  1. The name that was specified in lava-background-process-start
  2. (optional) An indication that you want to attach file(s) to the test run with specified mime type. See Recording test case data.

Handling test attachments

Handling of attachments is in the control of the test writer. A separate publishing location can be configured or text based data is simply to output the contents into the log file.

Deprecated elements

Handling Dependencies (Debian)

Warning

The install element of Lava-Test Test Definition 1.0 is DEPRECATED. See Write portable test definitions. Newly written Lava-Test Test Definition 1.0 files should not use install.

If your test requires some packages to be installed before its run it can express that in the install section with:

install:
    deps:
        - linux-libc-dev
        - build-essential

Adding Git/BZR Repositories

Warning

The install element of Lava-Test Test Definition 1.0 is DEPRECATED. See Write portable test definitions. Newly written Lava-Test Test Definition 1.0 files should not use install.

If the test needs code from a shared repository, the action can clone this data on your behalf with:

install:
    bzr-repos:
        - lp:lava-test
    git-repos:
        - git://git.linaro.org/people/davelong/lt_ti_lava.git

run:
    steps:
        - cd lt_ti_lava
        - echo "now in the git cloned directory"

git-repos

There are several options for customising git repository handling in the git-repos action, for example:

install:
    git-repos:
        - url: https://git.lavasoftware.org/lava/lava.git
          skip_by_default: False
        - url: https://git.lavasoftware.org/lava/lava.git
          destination:  lava-d-r
          branch:       release
        - url: https://git.lavasoftware.org/lava/lava.git
          destination:  lava-d-s
          branch:       staging
  • url is the git repository URL.
  • skip_by_default (optional) accepts a True or False. Repositories can be skipped by default in the test definition YAML and enabled for particular jobs directly in the job submission YAML, and vice versa.
  • destination (optional) is the directory in which the git repository given in url should be cloned, to override normal git behaviour.
  • branch (optional) is the branch within the git repository given in url that should be checked out after cloning.

Install Steps

Warning

The install element of Lava-Test Test Definition 1.0 is DEPRECATED. See Write portable test definitions. Newly written Lava-Test Test Definition 1.0 files should not use install.

Before the test shell code is executed, it will optionally do some install work if needed. For example if you needed to build some code from a git repo you could do:

install:
    git-repos:
        - git://git.linaro.org/people/davelong/lt_ti_lava.git

    steps:
        - cd lt_ti_lava
        - make

Note

The repo steps are done in the dispatcher itself. The install steps are run directly on the target.

Parse patterns

Warning

Parse patterns and fixup dictionaries are confusing and hard to debug. The syntax is Python and the support remains for compatibility with existing Lava Test Shell Definitions. With LAVA V2, it is recommended to move parsing into a custom script contained within the test definition repository. The script can simply call lava-test-case directly with the relevant options once the data is parsed. This has the advantage that the log output from LAVA can be tested directly as input for the script.

You may need to incorporate an existing test that doesn’t output results in in the required pass/fail/skip/unknown format required by LAVA. The parse section has a fixup mechanism that can help:

parse:
    pattern: "(?P<test_case_id>.*-*)\\s+:\\s+(?P<result>(PASS|FAIL))"
    fixupdict:
        PASS: pass
        FAIL: fail

Note

Pattern can be double-quoted or single quoted. If it’s double-quoted, special characters need to be escaped. Otherwise, no escaping is necessary.

Single quote example:

parse:
    pattern: '(?P<test_case_id>.*-*)\s+:\s+(?P<result>(PASS|FAIL))'
    fixupdict:
        PASS: pass
        FAIL: fail