Writing AutoQA Tests

Introduction

Here's some info on writing tests for AutoQA. There's four parts to a test: the test code, the test object, the Autotest control file, and the AutoQA control file. Typically they all live in a single directory, located in the tests/ dir of the autoqa source tree.

Start with a test
Before considering integrating a test into AutoQA or Autotest, create a working test. Creating a working test should not require knowledge of autotest or autoqa. This page outlines the process of integrating an existing test into AutoQA.

No support for per-package tests
AutoQA currently supports only generic Fedora tests (tests that concern packages - or other objects - in general). We have plans to support per-package tests in the future (e.g. tests for sshd, tests for gimp, etc). Until AutoQA support exists, consider merging your test into upstream's test suite, or including your test in the Fedora rpm package, and have it executed during %check or ask the package maintainer to manually execute tests and provide results during bodhi updates.

Write test code first

I'll say it again: Write the test first. The tests don't require anything from autotest or autoqa. You should have a working test before you even start thinking about AutoQA.

You can package up pre-existing tests or you can write a new test in whatever language you're comfortable with. It doesn't even need to return a meaningful exit code if you don't want it to (even though it is definitely better). You'll handle parsing the output and returning a useful result in the test object.

If you are writing a brand new test, there are some python libraries that have been developed for use in existing AutoQA tests. More information about this will be available once these libraries are packaged correctly, but they are not necessary to write your own tests. You can choose to use whatever language and libraries you want.

The test directory

Create a new directory to hold your test. The directory name will be used as the test name, and the test object name should match that. Choose a name that doesn't use spaces, dashes, or dots. Underscores are acceptable.

Drop your test code into the directory - it can be a bunch of scripts, a tarball of sources that may need compiling, whatever.

Next, from the directory autoqa/doc/, copy template files control.template, control.autoqa.template and test_class.py.template into your test directory. Rename them to control, control.autoqa and [testname].py, respectively.

The control file

The control file defines some metadata for this test - who wrote it, what kind of a test it is, what test arguments it uses from AutoQA, and so on. Here's an example control file:

control file for conflicts test

AUTHOR = "Will Woods <wwoods@redhat.com>"
TIME="SHORT"
NAME = 'conflict'
DOC = """
This test runs potential_conflict from yum-utils to check for possible
file / package conflicts.
"""
TEST_TYPE = 'CLIENT'
TEST_CLASS = 'General'
TEST_CATEGORY = 'Functional'

job.run_test('conflicts', config=autoqa_conf, **autoqa_args)

Required data

The following control file items are required for valid AutoQA tests. The first three are important for us, the rest is not so important but still required.

• NAME: The name of the test. Should match the test directory name, the test object name, etc.
• AUTHOR: Your name and email address.
• DOC: A verbose description of the test - its purpose, the logs and data it will generate, and so on.
• TIME: either 'SHORT', 'MEDIUM', or 'LONG'. This defines the expected runtime of the test - either 15 minutes, less than 4 hours, or more than 4 hours.
• TEST_TYPE: either 'CLIENT' or 'SERVER'. Use 'CLIENT' unless your test requires multiple machines (e.g. a client and server for network-based testing).
• TEST_CLASS: This is used to group tests in the UI. 'General' is fine. We may use this field to refer to the test event in the future.
• TEST_CATEGORY: This defines the category your test is a part of - usually this describes the general type of test it is. Examples include Functional, Stress, Performance, and Regression.

Optional data

The following control file items are optional, and infrequently used, for AutoQA tests.

DEPENDENCIES = 'POWER, CONSOLE'
SYNC_COUNT = 1

• DEPENDENCIES: Comma-separated list of hardware requirements for the test. Currently unsupported.
• SYNC_COUNT: The number of hosts to set up and synchronize for this test. Only relevant for SERVER-type tests that need to run on multiple machines.

Launching the test object

Most tests will have a line in the control file like this:

job.run_test('conflicts', config=autoqa_conf, **autoqa_args)

This will create a 'conflicts' test object (see below) and pass along the following variables.

autoqa_conf

Contains string with autoqa.conf file, usually located at /etc/autoqa/autoqa.conf. Note, though, that some of the values in autoqa_conf are changed by the autoqa harness while scheduling the testrun.

autoqa_args

A dictionary, containing all the event-specific variables (e.g. kojitag for post-koji-build event). Documentation on these is to be found in events/[eventname]/README files. Some more variables may be also present, as described in the template file.

Those variables will be inserted into the control file by the autoqa test harness when it's time to schedule the test.

The control.autoqa file

The control.autoqa file allows a test to define any scheduling requirements or modify input arguments. This file will decide whether to run this test at all, on what architectures/distributions it should run, and so on. It is evaluated on the AutoQA server before the test itself is scheduled and run on AutoQA client.

All variables available in control.autoqa are documented in doc/control.autoqa.template. You can override them to customize your test's scheduling. Basically you can influence:

• Which event the test runs for and under which conditions.
• The type of system the test needs. This includes system architecture, operating system version and whether the system supports virtualization (see autotest labels for additional information)
• Data passed from the event to the test object.

Here is example control.autoqa file:

# this test can be run just once and on any architecture,
# override the default set of architectures
archs = ['noarch']

# this test may be destructive, let's require a virtual machine for it
labels = ['virt']

# we want to run this test just for post-koji-build event;
# please note that 'execute' defaults to 'False' and to have
# the test scheduled, control.autoqa needs to complete with
# 'execute' set to 'True'
if event in ['post-koji-build']:
    execute = True

Similar to the control file, the control.autoqa file is a Python script, so you can execute conditional expressions, loops or virtually any other Python statements there. However, it is heavily recommended to keep this file as simple as possible and put all the logic to the test object.

Test Object

The test object is a python file that defines an object that represents your test. It handles the setup for the test (installing packages, modifying services, etc), running the test code, and sending results to Autotest (and other places).

Convention holds that the test object file - and the object itself - should have the same name as the test. For example, the conflicts test contains a file named conflicts.py, which defines a conflicts class, as follows:

from autotest_lib.client.bin import utils
from autoqa.test import AutoQATest
from autoqa.decorators import ExceptionCatcher

class conflicts(AutoQATest):
    ...

The name of the class must match the name given in the run_test() line of the control file, and test classes must be subclasses of the AutoQATest class. But don't worry too much about how this works - the test_class.py.template contains the skeleton of an appropriate test object. Just change the name of the file (and class!) to something appropriate for your test.

AutoQATest base class

This class contains the functionality common to all the tests. When you override some of its methods (like setup(), initialize() or run_once()) it is important to call the parent method first.

The most important attribute of this class is detail (an instance of TestDetail class) that is used for storing all test outcomes.

The most important methods include log() that you are advised to use for logging test output and post_results() that you can use for changing the way your test results are reported (if you're not satisfied with the default behavior).

Whenever your test crashes, the process_exception() method will automatically catch the exception and log it (more on that in the next section).

ExceptionCatcher decorator

When an unintended exception is raised during test setup (setup()), initialization (initialize()) or execution (run_once()) and ExceptionCatcher() decorator is used for these methods (the default), it calls the process_exception() method instead of simply crashing. In this way we are able to operate and submit results even of crashed tests.

When such event occurs, the test result is set to CRASHED, the exception traceback is added into the test output and the exception info is put into the test summary. Then the results are reported in a standard way (by creating log files and sending emails). Finally the original exception is re-raised.

If a different recovery procedure than process_exception() is desired, you may define the method and provide the method name as an argument to the decorator. For example, see below:

def my_exception_handler(self, exc = None):
   '''do something different'''

@ExceptionCatcher('self.my_exception_handler')
def run_once(self, **kwargs):
    ...

**kwargs parameter
Because of some nasty Autotest magic, it is required to have the **kwargs argument in the decorated function. This is because Autotest magic can not find out what is the correct subset of arguments from **autoqa_args to pass, so it passes them all - which causes error, if you don't have them all listed.

Test stages

setup()

This is an optional method of the test class. This is where you make sure that any required packages are installed, services are started, your test code is compiled, and so on. For example:

    @ExceptionCatcher()
    def setup(self):
        retval = utils.system('yum -y install httpd')
        assert retval == 0
        if utils.system('service httpd status') != 0:
            utils.system('service httpd start')

initialize()

This does any pre-test initialization that needs to happen. AutoQA tests typically uses this method to initialize various structures, set self.detail.id and similar attributes. This is an optional method.

All basic initialization is done in the AutoQATest class, so check it out, before you re-define it.

Call AutoQATest.initialize
If you re-implement the initialize function, make sure, that you call super(self.__class__, self).initialize(config) inside it, so all the required initialization is executed

run_once()

This is where the test code actually gets run. It's the only required method for your test object.

In short, this method should build the argument list, run the test binary and process the test result and output. For example, see below:

    @ExceptionCatcher()
    def run_once(self, baseurl, parents, name, **kwargs):
        super(self.__class__, self).run_once()

        cmd = './potential_conflict.py --tempcache --newest ' \
              '--repofrompath=target,%s --repoid=target' % baseurl

        out = utils.system_output(cmd, retain_output=True)
        self.log(out, printout=False)

This above example will run the command potential_conflict.py and save its output. It will raise CmdError if the command ends with non-zero exit code.

If you need to receive just the exit code of the command, use utils.system() method instead.

Additionally, if you need both the exit code and command output, use the built-in utils.run() method:

    cmd_result = utils.run(cmd, ignore_status=True, stdout_tee=utils.TEE_TO_LOGS, stderr_tee=utils.TEE_TO_LOGS)
    output = cmd_result.stdout
    retval = cmd_result.exit_status

Useful test object attributes

AutoQATest instances have the following attributes available:

outputdir       eg. results/<job>/<testname.tag>
resultsdir      eg. results/<job>/<testname.tag>/results
profdir         eg. results/<job>/<testname.tag>/profiling
debugdir        eg. results/<job>/<testname.tag>/debug
bindir          eg. tests/<test>
src             eg. tests/<test>/src
tmpdir          eg. tmp/<tempname>_<testname.tag>

Test Results

The AutoQATest class provides a detail attribute to be used for storing test results. This is an instance of TestDetail class and serves as a container for everything related to the test outcome.

If your test tests several independent things at once, you can create several TestDetail objects and then submit results for all of them manually. For example upgradepath test uses that for reporting results for every proposed Bodhi update. But this is really advanced stuff, see upgradepath or depcheck tests for inspiration.

Overall Result

The overall test result is stored in self.detail.result. You should set it in run_once() according to the result of your test. You can choose from these values:

• PASSED - the test has passed, there is no problem with it
• INFO - the test has passed, but there is some important information that a relevant person would very probably like to review
• FAILED - the test has failed, requirements are not met
• NEEDS_INSPECTION (default)- the test has failed, but a relevant person is needed to inspect it and possibly may waive the errors
• ABORTED - some third party error has occurred (networking error, external script used for testing has crashed, etc) and the test could not complete because of that. Re-running this test with same input arguments could solve this problem.
• CRASHED - the test has crashed because of a programming error somewhere in our code (test script or autoqa code). Close inspection is necessary to be able to solve this issue.

If no value is set in self.detail.result, a value of NEEDS_INSPECTION is used.

If an exception occurs, and is caught by the ExceptionCatcher decorator (i.e. you don't catch it yourself), self.detail.result is set to CRASHED.

Using ABORTED result properly

If you want to end your test with ABORTED result, simple set self.detail.result and then re-raise the original exception. self.detail.summary will be filled-in automatically (extracted from the exception message), if empty.

try:
    //download from Koji
except IOError, e: //or some other error
    self.detail.result = 'ABORTED'
    raise

If you don't have any exception to re-raise but still want to end the test, again set self.detail.result, but this time be sure to also provide an explanation in self.detail.summary and then end the test by raising autotest_lib.client.common_lib.error.TestFail. Alternatively you can provide the error explanation as an argument to the TestFail class instead of filling in self.detail.summary.

from autotest_lib.client.common_lib import error
foo = //do some stuff
if foo == None:
    self.detail.result = 'ABORTED'
    raise error.TestFail('No result returned from service bar')

Posting feedback into Bodhi

After the result of a test is known, it can be sent into Bodhi. You need to manually call post_results() method at the end of our test and provide a bodhi parameter.

        # Report all results to Bodhi
        for title, td in update_result.items():  # mapping of Bodhi update title -> TestDetail object
            self.post_results(td, bodhi = {'title': title})

Summary

The self.detail.summary should contain a few words summarizing the test output. It is then used in the log overview and in the email subject. E.g. for conflicts test it can be "69 packages with file conflicts". Don't repeat test name, test result or test ID in here.

Highlights

The self.highlights should contain a digest from the stdout/stderr generated by your test. Traditionally, this is used to draw attention to important warnings or errors. For example, you may have several hundred/thousand lines of test output (self.outputs), but you wouldn't want to inspect that everytime to determine the nature of a failure. Draw attention to specific issues by using self.highlights.

The self.highlights can contain a string, or a list of strings.

Detailed Output

Put any detailed output into the self.outputs variable. Usually it contains the stdout/stderr of your test script, but it may contain less or more, as you wish. This detailed output will probably represent the largest portion of the test result report.

The self.outputs can contain a string or a list of strings.

Extra Data

Further test-level info can be returned by using test.write_test_keyval(dict). The following example demonstrates extracting and saving the kernel version used when running a test:

extrainfo = dict()
for line in self.results.stdout:
    if line.startswith("kernel version "):
        extrainfo['kernelver'] = line.split()[3]
    ...
self.write_test_keyval(extrainfo)

In addition to test-level key/value pairs, per-iteration key/value information (e.g. performance metrics) can be recorded:

1. self.write_attr_keyval(attr_dict) - Store test attributes (string data). Test attributes are limited to 100 characters.
2. self.write_perf_keyval(perf_dict) - Store test performance metrics (numerical data). Performance values must be floating-point numbers.
3. self.write_iteration_keyval(attr_dict, perf_dict) - Storing both, attributes and performance data

Log files and scratch data

Autotest automatically logs all the client/server output, the full output of any commands you run, operating system variables and others and stores them on the server. There is a hyperlink to the directory with all these log files in every test report.

If you want to store a custom file (like your own log), just save it to self.resultsdir directory. All those files will be saved at the end of the test. On the other hand, any files written to self.tmpdir will be discarded.

output.log

After the test completes, an output.log file is created in the directory referenced by self.resultsdir. The output.log file combines all test output variables (self.result/summary/highlights/outputs) and writes them in a consistent format - the same format that is used for email reports. You can use this file to review the final test report even if you don't have access to the email one.

How to run AutoQA tests

Install AutoQA from GIT

First of all, you'll need to checkout some version from GIT. You can either use master, or some tagged 'release'.

To checkout master branch:

git clone git://git.fedorahosted.org/autoqa.git autoqa
cd autoqa

To checkout tagged release:

git clone git://git.fedorahosted.org/autoqa.git autoqa
cd autoqa
git tag -l
# now you'll get a list of tags, at the time of writing this document, the latests tag was v0.3.5-1
git checkout -b v0.3.5-1 tags/v0.3.5-1

Add your test

The best way to add your test into the directory structure is to create a new branch, copy your test and make install autoqa.

git checkout -b my_new_awesome_test
cp -r /path/to/directory/with/your/test ./tests
make clean install

Dependencies
It's possible that make install will fail due to missing some python modules (e.g. turbogears2). In that case install them using yum.

Run your test

This is dependent on the event, your test is supposed to run under. Let's assume, that it is the post-koji-build.

/usr/share/autoqa/post-koji-build/watch-koji-builds.py --dry-run

This command will show you current koji builds e.g.

No previous run - checking builds in the past 3 hours
autoqa post-koji-build --kojitag dist-f12-updates-candidate --arch x86_64 --arch i686 espeak-1.42.04-1.fc12
autoqa post-koji-build --kojitag dist-f11-updates-candidate --arch x86_64 kdemultimedia-4.3.4-1.fc11
autoqa post-koji-build --kojitag dist-f11-updates-candidate --arch x86_64 kdeplasma-addons-4.3.4-1.fc11
autoqa post-koji-build --kojitag dist-f12-updates-candidate --arch x86_64 --arch i686 cryptopp-5.6.1-0.1.svn479.fc12
autoqa post-koji-build --kojitag dist-f12-updates-candidate --arch x86_64 drupal-6.15-1.fc12
autoqa post-koji-build --kojitag dist-f12-updates-candidate --arch x86_64 --arch i686 seamonkey-2.0.1-1.fc12
... output trimmed ...

So to run your test, just select one of the lines, and add parameters --test name_of_your_test --local, which will locally execute the test you just wrote. If you wanted to run rpmlint, for example, the command would be

autoqa post-koji-build --kojitag dist-f12-updates-candidate --arch x86_64 --arch i686 espeak-1.42.04-1.fc12 --test rpmlint --local

--local
It is important to add the --local parameter. If you won't, the test will fail to run provided that you don't have Autotest server installed and configured.

Links

• Verifying AutoQA tests

Autotest documentation

• ControlRequirements (covers the requirements for control files)
• AddingTest (covers the basics of test writing)
• AutotestApi (more detailed info about writing tests)