bind/bin/tests/system/conftest.py

# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
#
# SPDX-License-Identifier: MPL-2.0
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0.  If a copy of the MPL was not distributed with this
# file, you can obtain one at https://mozilla.org/MPL/2.0/.
#
# See the COPYRIGHT file distributed with this work for additional
# information regarding copyright ownership.

import os
import pytest


# ======================= LEGACY=COMPATIBLE FIXTURES =========================
# The following fixtures are designed to work with both pytest system test
# runner and the legacy system test framework.
#
# FUTURE: Rewrite the individual port fixtures to re-use the `ports` fixture.


@pytest.fixture(scope="module")
def named_port():
    return int(os.environ.get("PORT", default=5300))


@pytest.fixture(scope="module")
def named_tlsport():
    return int(os.environ.get("TLSPORT", default=8853))


@pytest.fixture(scope="module")
def named_httpsport():
    return int(os.environ.get("HTTPSPORT", default=4443))


@pytest.fixture(scope="module")
def control_port():
    return int(os.environ.get("CONTROLPORT", default=9953))


# ======================= PYTEST SYSTEM TEST RUNNER ==========================
# From this point onward, any setting, fixtures or functions only apply to the
# new pytest runner. Ideally, these would be in a separate file. However, due
# to how pytest works and how it's used by the legacy runner, the best approach
# is to have everything in this file to avoid duplication and set the
# LEGACY_TEST_RUNNER if pytest is executed from the legacy framework.
#
# FUTURE: Once legacy runner is no longer supported, remove the env var and
# don't branch the code.

if os.getenv("LEGACY_TEST_RUNNER", "0") == "0":
    from functools import partial
    import logging
    from pathlib import Path
    import re
    import shutil
    import subprocess
    import tempfile
    import time
    from typing import Any, Dict, List, Optional

    # Silence warnings caused by passing a pytest fixture to another fixture.
    # pylint: disable=redefined-outer-name

    # ----------------------- Globals definition -----------------------------

    LOG_FORMAT = "%(asctime)s %(levelname)7s:%(name)s  %(message)s"
    XDIST_WORKER = os.environ.get("PYTEST_XDIST_WORKER", "")
    FILE_DIR = os.path.abspath(Path(__file__).parent)
    ENV_RE = re.compile("([^=]+)=(.*)")
    PORT_MIN = 5001
    PORT_MAX = 32767
    PORTS_PER_TEST = 20

    # ---------------------- Module initialization ---------------------------

    def parse_env(env_text):
        """Parse the POSIX env format into Python dictionary."""
        out = {}
        for line in env_text.splitlines():
            match = ENV_RE.match(line)
            if match:
                out[match.groups()[0]] = match.groups()[1]
        return out

    def get_env(cmd):
        try:
            proc = subprocess.run(
                [cmd],
                shell=True,
                check=True,
                cwd=FILE_DIR,
                stdout=subprocess.PIPE,
            )
        except subprocess.CalledProcessError as exc:
            logging.error("failed to get shell env: %s", exc)
            raise exc
        env_text = proc.stdout.decode("utf-8")
        return parse_env(env_text)

    # Read common environment variables for running tests from conf.sh.
    # FUTURE: Remove conf.sh entirely and define all variables in pytest only.
    CONF_ENV = get_env(". ./conf.sh && env")
    os.environ.update(CONF_ENV)
    logging.debug("conf.sh env: %s", CONF_ENV)

    # --------------------------- pytest hooks -------------------------------

    def pytest_configure():
        # Ensure this hook only runs on the main pytest instance if xdist is
        # used to spawn other workers.
        if not XDIST_WORKER:
            logging.debug("compiling required files")
            env = os.environ.copy()
            env["TESTS"] = ""  # disable automake test framework - compile-only
            try:
                # FUTURE: Remove the need to run this compilation command
                # before executing tests. Currently it's only here to have
                # on-par functionality with the legacy test framework.
                proc = subprocess.run(
                    "make -e check",
                    shell=True,
                    check=True,
                    cwd=FILE_DIR,
                    stdout=subprocess.PIPE,
                    stderr=subprocess.STDOUT,
                    env=env,
                )
            except subprocess.CalledProcessError as exc:
                logging.debug(exc.stdout)
                logging.error("failed to compile test files: %s", exc)
                raise exc
            logging.debug(proc.stdout)

    # --------------------------- Fixtures -----------------------------------

    @pytest.fixture(scope="session")
    def modules():
        """Sorted list of all modules. Used to determine port distribution."""
        mods = []
        for dirpath, _dirs, files in os.walk(os.getcwd()):
            for file in files:
                if file.startswith("tests_") and file.endswith(".py"):
                    mod = f"{dirpath}/{file}"
                    mods.append(mod)
        return sorted(mods)

    @pytest.fixture(scope="session")
    def module_base_ports(modules):
        """
        Dictionary containing assigned base port for every module.

        Note that this is a session-wide fixture. The port numbers are
        deterministically assigned before any testing starts. This fixture MUST
        return the same value when called again during the same test session.
        When running tests in parallel, this is exactly what happens - every
        worker thread will call this fixture to determine test ports.
        """
        port_min = PORT_MIN
        port_max = PORT_MAX - len(modules) * PORTS_PER_TEST
        if port_max < port_min:
            raise RuntimeError(
                "not enough ports to assign unique port set to each module"
            )

        # Rotate the base port value over time to detect possible test issues
        # with using random ports. This introduces a very slight race condition
        # risk. If this value changes between pytest invocation and spawning
        # worker threads, multiple tests may have same port values assigned. If
        # these tests are then executed simultaneously, the test results will
        # be misleading.
        base_port = int(time.time() // 3600) % (port_max - port_min)

        return {mod: base_port + i * PORTS_PER_TEST for i, mod in enumerate(modules)}

    @pytest.fixture(scope="module")
    def base_port(request, module_base_ports):
        """Start of the port range assigned to a particular test module."""
        port = module_base_ports[request.fspath]
        return port

    @pytest.fixture(scope="module")
    def ports(base_port):
        """Dictionary containing port names and their assigned values."""
        return {
            "PORT": str(base_port),
            "TLSPORT": str(base_port + 1),
            "HTTPPORT": str(base_port + 2),
            "HTTPSPORT": str(base_port + 3),
            "EXTRAPORT1": str(base_port + 4),
            "EXTRAPORT2": str(base_port + 5),
            "EXTRAPORT3": str(base_port + 6),
            "EXTRAPORT4": str(base_port + 7),
            "EXTRAPORT5": str(base_port + 8),
            "EXTRAPORT6": str(base_port + 9),
            "EXTRAPORT7": str(base_port + 10),
            "EXTRAPORT8": str(base_port + 11),
            "CONTROLPORT": str(base_port + 12),
        }

    @pytest.fixture(scope="module")
    def env(ports):
        """Dictionary containing environment variables for the test."""
        env = CONF_ENV.copy()
        env.update(ports)
        env["builddir"] = f"{env['TOP_BUILDDIR']}/bin/tests/system"
        env["srcdir"] = f"{env['TOP_SRCDIR']}/bin/tests/system"
        return env

    @pytest.fixture(scope="module")
    def system_test_name(request):
        """Name of the system test directory."""
        path = Path(request.fspath)
        return path.parent.name

    @pytest.fixture(scope="module")
    def logger(system_test_name):
        """Logging facility specific to this test."""
        return logging.getLogger(system_test_name)

    @pytest.fixture(scope="module")
    def system_test_dir(request, env, system_test_name, logger):
        """
        Temporary directory for executing the test.

        This fixture is responsible for creating (and potentially removing) a
        copy of the system test directory which is used as a temporary
        directory for the test execution.

        FUTURE: This removes the need to have clean.sh scripts.
        """

        # Create a temporary directory with a copy of the original system test dir contents
        system_test_root = Path(f"{env['TOP_BUILDDIR']}/bin/tests/system")
        testdir = Path(
            tempfile.mkdtemp(prefix=f"{system_test_name}_tmp_", dir=system_test_root)
        )
        shutil.rmtree(testdir)
        shutil.copytree(system_test_root / system_test_name, testdir)

        # Configure logger to write to a file inside the temporary test directory
        logger.handlers.clear()
        logger.setLevel(logging.DEBUG)
        handler = logging.FileHandler(testdir / "pytest.log.txt", mode="w")
        formatter = logging.Formatter(LOG_FORMAT)
        handler.setFormatter(formatter)
        logger.addHandler(handler)

        # System tests are meant to be executed from their directory - switch to it.
        old_cwd = os.getcwd()
        os.chdir(testdir)
        logger.info("switching to tmpdir: %s", testdir)
        try:
            yield testdir  # other fixtures / tests will execute here
        finally:
            os.chdir(old_cwd)
            logger.debug("changed workdir to: %s", old_cwd)

            # cases when tempdir should be kept are handled in follow-up commits
            logger.debug("deleting temporary directory")
            shutil.rmtree(testdir)

    def _run_script(  # pylint: disable=too-many-arguments
        env,
        logger,
        system_test_dir: Path,
        interpreter: str,
        script: str,
        args: Optional[List[str]] = None,
    ):
        """Helper function for the shell / perl script invocations (through fixtures below)."""
        if args is None:
            args = []
        path = Path(script)
        if not path.is_absolute():
            # make sure relative paths are always relative to system_dir
            path = system_test_dir.parent / path
        script = str(path)
        cwd = os.getcwd()
        if not path.exists():
            raise FileNotFoundError(f"script {script} not found in {cwd}")
        logger.debug("running script: %s %s %s", interpreter, script, " ".join(args))
        logger.debug("  workdir: %s", cwd)
        stdout = b""
        returncode = 1
        try:
            proc = subprocess.run(
                [interpreter, script] + args,
                env=env,
                check=True,
                stdout=subprocess.PIPE,
                stderr=subprocess.STDOUT,
            )
        except subprocess.CalledProcessError as exc:
            stdout = exc.stdout
            returncode = exc.returncode
            raise exc
        else:
            stdout = proc.stdout
            returncode = proc.returncode
        finally:
            if stdout:
                for line in stdout.decode().splitlines():
                    logger.debug("    %s", line)
            logger.debug("  exited with %d", returncode)
        return proc

    @pytest.fixture(scope="module")
    def shell(env, system_test_dir, logger):
        """Function to call a shell script with arguments."""
        return partial(_run_script, env, logger, system_test_dir, env["SHELL"])

    @pytest.fixture(scope="module")
    def perl(env, system_test_dir, logger):
        """Function to call a perl script with arguments."""
        return partial(_run_script, env, logger, system_test_dir, env["PERL"])

    @pytest.fixture(scope="module", autouse=True)
    def system_test(  # pylint: disable=too-many-arguments,too-many-statements
        request,
        env: Dict[str, str],
        logger,
        system_test_dir,
        shell,
        perl,
    ):
        """
        Driver of the test setup/teardown process. Used automatically for every test module.

        This is the most important one-fixture-to-rule-them-all. Note the
        autouse=True which causes this fixture to be loaded by every test
        module without the need to explicitly specify it.

        When this fixture is used, it utilizes other fixtures, such as
        system_test_dir, which handles the creation of the temporary test
        directory.

        Afterwards, it checks the test environment and takes care of starting
        the servers. When everything is ready, that's when the actual tests are
        executed. Once that is done, this fixture stops the servers and checks
        for any artifacts indicating an issue (e.g. coredumps).

        Finally, when this fixture reaches an end (or encounters an exception,
        which may be caused by fail/skip invocations), any fixtures which is
        used by this one are finalized - e.g. system_test_dir performs final
        checks and cleans up the temporary test directory.
        """

        def check_net_interfaces():
            try:
                perl("testsock.pl", ["-p", env["PORT"]])
            except subprocess.CalledProcessError as exc:
                logger.error("testsock.pl: exited with code %d", exc.returncode)
                pytest.skip("Network interface aliases not set up.")

        def check_prerequisites():
            try:
                shell(f"{system_test_dir}/prereq.sh")
            except FileNotFoundError:
                pass  # prereq.sh is optional
            except subprocess.CalledProcessError:
                pytest.skip("Prerequisites missing.")

        def setup_test():
            try:
                shell(f"{system_test_dir}/setup.sh")
            except FileNotFoundError:
                pass  # setup.sh is optional
            except subprocess.CalledProcessError as exc:
                logger.error("Failed to run test setup")
                pytest.fail(f"setup.sh exited with {exc.returncode}")

        def start_servers():
            try:
                perl("start.pl", ["--port", env["PORT"], system_test_dir.name])
            except subprocess.CalledProcessError as exc:
                logger.error("Failed to start servers")
                pytest.fail(f"start.pl exited with {exc.returncode}")

        def stop_servers():
            try:
                perl("stop.pl", [system_test_dir.name])
            except subprocess.CalledProcessError as exc:
                logger.error("Failed to stop servers")
                pytest.fail(f"stop.pl exited with {exc.returncode}")

        def get_core_dumps():
            try:
                shell("get_core_dumps.sh", [system_test_dir.name])
            except subprocess.CalledProcessError as exc:
                logger.error("Found core dumps")
                pytest.fail(f"get_core_dumps.sh exited with {exc.returncode}")

        os.environ.update(env)  # Ensure pytests have the same env vars as shell tests.
        logger.info(f"test started: {request.node.name}")
        port = int(env["PORT"])
        logger.info("using port range: <%d, %d>", port, port + PORTS_PER_TEST - 1)

        # Perform checks which may skip this test.
        check_net_interfaces()
        check_prerequisites()

        setup_test()
        try:
            start_servers()
            logger.debug("executing test(s)")
            yield
        finally:
            logger.debug("test(s) finished")
            stop_servers()
            get_core_dumps()