Enforcing pylint standards and default for our test code seems
counter-productive. Since most of the newly added code are tests or is
test-related, encountering these checks rarely make us refactor the code
in other ways and we just disable these checks individually. Code that
is too complex or convoluted will be pointed out in reviews anyways.
Instead of invoking get_algorithms.py script repeatedly (which may yield
different results), move the algorithm configuration to an isctest
module. This ensures the variables are consistent across the entire test
run.
Make sure all initialization takes place in isctest.vars.__init__ and
export the initial env vars there. Remove the no longer needed env
fixture and use os.environ instead.
Provide a single point of access to all the variables used by tests. Use
a custom dict-like structure to access the underlying data without
making a copy. This allows the individual modules to update the contents
at runtime, which is used for some variables.
Remove conf.sh.in and move the environment variables into isctest/vars
python package. This enabled the removal of an ugly pytest hack which
loaded and parsed these variables from the environment.
Initializing the conftest logging upon importing the isctest package
isn't practical when there are standalone pieces which can be used
outside of the testing framework, such as the asyncdnsserver module.
Unify the different loggers (conftest, module, test) into a single
interface. Remove the need to select the proper logger by automatically
selecting the most-specific logger currently available.
This also removes the need to use the logger/mlogger fixtures manually
and pass these around. This was especially annoying and unwieldy when
splitting the test cases into functions, because logger had to always be
passed around. Instead, it is now possible to use the
isctest.log.(debug,info,warning,error) functions.
Controlling named instances using RNDC is a common action in BIND 9
system tests. However, there is currently no standardized way of doing
that from Python-based system tests, which leads to code duplication.
Add a set of Python classes and pytest fixtures which intend to simplify
and standardize use of RNDC in Python-based system tests.
For now, RNDC commands are sent to servers by invoking the rndc binary.
However, a switch to a native Python module able to send RNDC commands
without executing external binaries is expected to happen soon. Even
when that happens, though, having the capability to invoke the rndc
binary (in order to test it) will remain useful. Define a common Python
interface that such "RNDC executors" should implement (RNDCExecutor), in
order to make switching between them convenient.
Co-authored-by: Štěpán Balážik <stepan@isc.org>
Create a utility package for code shared by the python tests. The
utility functions should use reasonable defaults and be split up into
modules according to their functionality.
Ensure assert rewriting is enabled for the modules to get the most
useful output from pytest.
The previous symlink name convention was prone to name collisions If a
system test contained both a shell test and a pytest module of the same
name (e.g. dnstap test has both tests.sh and tests_dnstap.py), then
these would have the same convenience symlink, which could cause test
setup issues as well as confusion when examining test artifacts.
Update the naming convention to include the full pytest module name.
This results in a slightly more verbose names for shell tests (e.g.
dnstap_sh_dnstap instead of the previous dnstap_dnstap), but it removes
the chance of a collision.
Reorganize individual port fixtures and re-use the ports fixture to
obtain their number. Store it as integer and only cast it to string when
setting it as environment variable.
Remove code fork for legacy runner, reorganize imports and move a
pylint-silencing snippet to the top of the file. The rest of the code
was just unindented.
To allow concurrent invocations of pytest, it is necessary to assign
ports properly to avoid conflicts. In order to do that, pytest needs to
know a complete list of all test modules.
When pytest is invoked from run.sh, the current working directory is the
system test directory. To properly detect other tests, the conftest.py
has to look in the bin/tests/system directory, rather than the current
working directory.
Using check_PROGRAMS would postpone compiling the binaries needed by
system tests until `make check` would be called. Since it's preferable
to invoke pytest directly to run the system test suite, compile these
binaries without installing them during `make all` instead by using
noinst_PROGRAMS.
This removes the need to use TESTS= make -e check hack invoked from
pytest to work around this issue.
While it'd be fairly easy to split the function up into smaller ones,
the readability wouldn't be improved in this case. Silence the
suggestions instead.
While temporary directories are useful for test execution to keep
everything clean, they are difficult to work with manually. Create a
symlink for each test artifact directory with a stable and predictable
path. The symlink always either points to the latest artifacts, or is
missing in case the last run succeeded.
Ensure these symlinked directories aren't detected as test suites by the
pytest runner.
This test uses key timing metadata to do rollovers, this is no longer
applicable with 'dnssec-policy'. Note that with 'dnssec-policy' key
timing metadata is still written, but it is not used for determining
what and when to do key rollovers.
The module-level logger has a handler that writes into a temporary
directory. Ensure the logging output is flushed and the handler is
closed before attempting to remove this temporary directory.
EL8+ systems declare "which" function using environment variables in the
/etc/profile.d/which2.sh file. Because of our suboptimal environment
variable detection, which is required in order to support the legacy
runner, these variables are picked up by the pytest runner.
If subprocesses are spawned with these environment variables set, it
will cause the following issue when they spawn yet another subprocess:
/bin/sh: which: line 1: syntax error: unexpected end of file
/bin/sh: error importing function definition for `which'
Instantiate a new logger that is used during pytest initialization /
configuration. This logging isn't handled by pytest itself, since it
happens outside of any tests or fixtures.
Root logger can't be reused for this purpose, because that would
duplicate the logs. Instead, create a conftest-specific logger for this
purpose.
Unfortunately, this introduces another log file,
pytest.conftest.log.txt, which contains only the logging from pytest
initialization. However, unless one is debugging the runner /
environment, there should be no need to investigate this file.
In order to take the most advantage of parallel execution of tests,
ensure certain long running tests are scheduled first.
The list of tests considered long-running was created empirically. In
addition to the test run time, its position in the default
(alphabetical) ordering was also taken into account.
The logger fixture is provided as a test-level logging facility which
can be easily passed to tests to enable capturing and/or displaying
messages from tests written in Python.
While this works optimally with the pytest runner, messages on INFO
level or above will also be visible when using the legacy runner.
If a test fails with an assertion failure or exception, its content
along with traceback is displayed in pytest output. This information
should be preserved in the test-specific logger for a given system test
to make it easier to debug test failures.
In order to avoid issues with decoding/encoding env variables due to
different encodings on different systems, deal with the environment
variables directly as bytes.
The loadscope setting is required for parallel execution of our system
tests using pytest. The option ensure that all tests within a single
(module) scope will be assigned to the same worker.
This is neccessary because the worker sets up the nameservers for all
the tests within a module scope. If tests from the same module would be
assigned to different workers, then the setup could happen multiple
times, causing a race condition. This happens because each module uses
deterministic port numbers for the nameservers.
In order to run the shell system tests, the pytest runner has to pick
them up somehow. Adding an extra python file with a single function
for the shell tests for each system test proved to be the most
compatible way of running the shell tests across older pytest/xdist
versions.
Modify the legacy run.sh script to ignore these pytest-runner specific
glue files when executing tests written in pytest.
Special care needs to be taken to support older pytest / xdist versions.
The target versions are what is available in EL8, since that seems to
have the oldest versions that can be reasonably supported.
When an issue occurs inside a fixture (e.g. servers fail to start/stop),
the test result won't be detected as failed, but rather an error will be
thrown.
To ensure the tempdir is kept even if the test itself passes but the
system_test() fixture throws an error, a different mechanism is needed.
At the start of the critical test setup section, note that the fixture
hasn't finished yet. When this is detected in the system_test_dir()
fixture, it is recognized as error in test setup/teardown and the temp
directory is kept.
This may seem cumbersome, because it is. It's basically a workaround for
the way pytest handles fixtures and test errors in general.
The temporary directory contains artifacts for the pytest module. That
module may contain multiple individual tests which were executed
sequentially. The artifacts should be kept if even one of these tests
failed.
Since pytest doesn't have any facility to expose test results to
fixtures, customize the pytest_runtest_makereport() hook to enable that.
It stores the test results into a session scope variable which is
available in all fixtures.
When deciding whether to remove the temporary directory, find the
relevant test results for this module and don't remove the tmpdir if any
one the tests failed.
For every pytest module, create a copy of its system test directory and
run the test from that directory. This makes it easier to clean up
afterwards and makes it less error-prone when re-running (failed) tests.
Configure the logger to capture the module's log output into a separate
file available from the temporary directory. This is quite convenient
for exploring failures.
Cases where temporary directory should be kept are handled in a
follow-up commits.
This is basically the pytest re-implementation of the run.sh script.
The fixture is applied to every module and ensures complete test
setup/teardown, such as starting/stopping servers, detecting coredumps
etc.
Note that the fixture system_test_dir is not defined yet. It is omitted
now for review readability and it's added in follow-up commits.
Add fixtures for deriving system test name from the directory name and
for a module-specific logger.
Add fixtures to execute shell and perl scripts. Similar to how run.sh
calls commands, this functionality is also needed in pytest. The
fixtures take care of switching to a proper directory, logging
everything and handling errors.
Note that the fixture system_test_dir is not defined yet. It is omitted
now for review readability and it's added in follow-up commits.
This is basically a pytest re-implementation of the get_ports.sh script.
The main difference is that ports are assigned on a module basis, rather
than a directory basis. Module is the new atomic unit for parallel
execution, therefore it needs to have unique ports to avoid collisions.
Each module gets its ports through the env fixture which is updated with
ports and other module-specific variables.
Some system tests require extra programs and/or dependencies to be
compiled first. This is done via `make check` with the automake
framework when using check_* variables such as check_PROGRAMS.
To avoid running any tests via the automake framework, set the TESTS
env variable to empty string and utilize `make -e check` to override
default Makefile variables with environment ones. This ensures automake
will only compile the needed dependencies without running any tests.
Additional consideration needs to be taken for xdist. The compilation
command should be called just once before any tests are executed. To
achieve that, use the pytest_configure() hook and check that the
PYTEST_XDIST_WORKER env variable isn't set -- if it is, it indicates
we're in the spawned xdist worker and the compilation was already done
by the main pytest process that spawned the workers.
This is mostly done to have on-par functionality with legacy test
framework. In the future, we should get rid of the need to run "empty"
make -e check and perhaps compile test-stuff by default.
The commands executed by pytest during a system test need to have the
same environment variables set as if they were executed by the run.sh
shell script.
It was decided that for the moment, legacy way of executing system tests
with run.sh should be kept, which complicates things a bit. In order to
avoid duplicating the required variables in both conf.sh and pytest, it
was decided to use the existing conf.sh as the only authoritative
place for the variables.
It is necessary to process the environment variables from conf.sh right
when conftest.py is loaded, since they might be needed right away (e.g.
to test for feature support during test collection).
This solution is a bit hacky and is only meant to be used during the
transitory phase when both pytest and the legacy run.sh are both
supported. In the future, a superior pytest-only solution should be
used.
For discussion of other options, refer to
https://gitlab.isc.org/isc-projects/bind9/-/merge_requests/6809#note_318889
The legacy system test framework uses pytest to execute some tests.
Since it'd be quite difficult to convince pytest to decide whether to
include conftest.py (or which ones to include when launching from
subdir), it makes more sense to have a shared conftest.py which is used
by both the legacy test runner invocations of pytest and the new pytest
system test runner. It is ugly, but once we drop support for the legacy
runner, we'll get rid of it.
Properly scope the *port fixtures in order to ensure they'll work as
expected with the new pytest runner. Instead of using "session" (which
means the fixture is only evaluated once for the entire execution of
pytest), use "module" scope, which is evaluated separately for each
module. The legacy runner invoked pytest for each system test
separately, while the new pytest runner is invoked once for all system
tests -- therefore it requires the more fine-grained "module" scope to
for the fixtures to work properly.
Remove python shebang, as conftest.py isn't supposed to be an executable
script.
