[Cast Streaming] Add standalone python test script

This patch adds standalone_e2e.py, a simple-ish script that exercises
the standalone sender and receiver executables.

Change-Id: Ibf8c8580ebf6759f03fa17c41e9034bb91f93513
Reviewed-on: https://chromium-review.googlesource.com/c/openscreen/+/3001104
Commit-Queue: Jordan Bayles <jophba@chromium.org>
Reviewed-by: mark a. foltz <mfoltz@chromium.org>

4 files changed, 309 insertions, 1 deletions

diff --git a/cast/standalone_e2e.py b/cast/standalone_e2e.py
new file mode 100755
index 00000000..b27e3c65
--- /dev/null
+++ b/cast/standalone_e2e.py
@@ -0,0 +1,302 @@
+#!/usr/bin/env python3
+# Copyright 2021 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+"""
+This script is intended to cover end to end testing for the standalone sender
+and receiver executables in cast. This ensures that the basic functionality of
+these executables is not impaired, such as the TLS/UDP connections and encoding
+and decoding video.
+"""
+
+import argparse
+import os
+import pathlib
+import logging
+import subprocess
+import sys
+import time
+import unittest
+import ssl
+from collections import namedtuple
+
+from enum import IntFlag
+from urllib import request
+
+# Environment variables that can be overridden to set test properties.
+ROOT_ENVVAR = 'OPENSCREEN_ROOT_DIR'
+BUILD_ENVVAR = 'OPENSCREEN_BUILD_DIR'
+
+TEST_VIDEO_NAME = 'Contador_Glam.mp4'
+# NOTE: we use the HTTP protocol instead of HTTPS due to certificate issues
+# in the legacy urllib.request API.
+TEST_VIDEO_URL = ('https://storage.googleapis.com/openscreen_standalone/' +
+                  TEST_VIDEO_NAME)
+
+PROCESS_TIMEOUT = 15  # seconds
+
+# Open Screen test certificates expire after 3 days. We crop this slightly (by
+# 8 hours) to account for potential errors in time calculations.
+CERT_EXPIRY_AGE = (3 * 24 - 8) * 60 * 60
+
+# These properties are based on compiled settings in Open Screen, and should
+# not change without updating this file.
+TEST_CERT_NAME = 'generated_root_cast_receiver.crt'
+TEST_KEY_NAME = 'generated_root_cast_receiver.key'
+SENDER_BINARY_NAME = 'cast_sender'
+RECEIVER_BINARY_NAME = 'cast_receiver'
+
+EXPECTED_RECEIVER_MESSAGES = [
+    "CastService is running.", "Found codec: opus (known to FFMPEG as opus)",
+    "Found codec: vp8 (known to FFMPEG as vp8)",
+    "Successfully negotiated a session, creating SDL players.",
+    "Receivers are currently destroying, resetting SDL players."
+]
+
+EXPECTED_SENDER_MESSAGES = [
+    "Launching Mirroring App on the Cast Receiver",
+    "Max allowed media bitrate (audio + video) will be",
+    "Contador_Glam.mp4 (starts in one second)...",
+    "The video capturer has reached the end of the media stream.",
+    "The audio capturer has reached the end of the media stream.",
+    "Video complete. Exiting...", "Shutting down..."
+]
+
+MISSING_LOG_MESSAGE = """Missing an expected message from either the sender
+or receiver. This either means that one of the binaries misbehaved, or you
+changed or deleted one of the log messages used for validation. Please ensure
+that the necessary log messages are left unchanged, or update this
+test suite's expectations."""
+
+DESCRIPTION = """Runs end to end tests for the standalone Cast Streaming sender
+and receiver. By default, this script assumes it is being ran from a current
+working directory inside Open Screen's source directory, and uses
+<root_dir>/out/Default as the build directory. To override these, set the
+OPENSCREEN_ROOT_DIR and OPENSCREEN_BUILD_DIR environment variables. If the root
+directory is set and the build directory is not,
+<OPENSCREEN_ROOT_DIR>/out/Default will be used.
+
+See below for the the help output generated by the `unittest` package."""
+
+
+def _set_log_level(is_verbose):
+    """Sets the logging level, either DEBUG or ERROR as appropriate."""
+    level = logging.DEBUG if is_verbose else logging.INFO
+    logging.basicConfig(stream=sys.stdout, level=level)
+
+
+def _get_loopback_adapter_name():
+    """Retrieves the name of the loopback adapter (lo on Linux/lo0 on Mac)."""
+    if sys.platform == 'linux' or sys.platform == 'linux2':
+        return 'lo'
+    if sys.platform == 'darwin':
+        return 'lo0'
+    return None
+
+
+def _get_file_age_in_seconds(path):
+    """Get the age of a given file in seconds"""
+    # Time is stored in seconds since epoch
+    file_last_modified = 0
+    if path.exists():
+        file_last_modified = path.stat().st_mtime
+    return time.time() - file_last_modified
+
+
+def _get_build_paths():
+    """Gets the root and build paths (either default or from the environment
+    variables), and sets related paths to binaries and files."""
+    root_path = pathlib.Path(
+    os.environ[ROOT_ENVVAR] if os.getenv(ROOT_ENVVAR) else subprocess.
+    getoutput('git rev-parse --show-toplevel'))
+    assert root_path.exists(), 'Could not find openscreen root!'
+
+    build_path = pathlib.Path(os.environ[BUILD_ENVVAR]) if os.getenv(
+        BUILD_ENVVAR) else root_path.joinpath('out',
+                                                    'Default').resolve()
+    assert build_path.exists(), 'Could not find openscreen build!'
+
+    BuildPaths = namedtuple("BuildPaths",
+                            "root build test_video cast_receiver cast_sender")
+    return BuildPaths(root = root_path,
+        build = build_path,
+        test_video = build_path.joinpath(TEST_VIDEO_NAME).resolve(),
+        cast_receiver = build_path.joinpath(RECEIVER_BINARY_NAME).resolve(),
+        cast_sender = build_path.joinpath(SENDER_BINARY_NAME).resolve()
+        )
+
+
+class TestFlags(IntFlag):
+    """
+    Test flags, primarily used to control sender and receiver configuration
+    to test different features of the standalone libraries.
+    """
+    UseRemoting = 1
+    UseAndroidHack = 2
+
+
+class StandaloneCastTest(unittest.TestCase):
+    """
+    Test class for setting up and running end to end tests on the
+    standalone sender and receiver binaries. This class uses the unittest
+    package, so methods that are executed as tests all have named prefixed
+    with "test_".
+
+    This suite sets the current working directory to the root of the Open
+    Screen repository, and references all files from the root directory.
+    Generated certificates should always be in |cls.build_paths.root|.
+    """
+
+    @classmethod
+    def setUpClass(cls):
+        """Shared setup method for all tests, handles one-time updates."""
+        cls.build_paths = _get_build_paths()
+        os.chdir(cls.build_paths.root)
+        cls.download_video()
+        cls.generate_certificates()
+
+    @classmethod
+    def download_video(cls):
+        """Downloads the test video from Google storage."""
+        if os.path.exists(cls.build_paths.test_video):
+            logging.debug('Video already exists, skipping download...')
+            return
+
+        logging.debug('Downloading video from %s', TEST_VIDEO_URL)
+        with request.urlopen(TEST_VIDEO_URL, context=ssl.SSLContext()) as url:
+            with open(cls.build_paths.test_video, 'wb') as file:
+                file.write(url.read())
+
+    @classmethod
+    def generate_certificates(cls):
+        """Generates test certificates using the cast receiver."""
+        cert_age = _get_file_age_in_seconds(pathlib.Path(TEST_CERT_NAME))
+        key_age = _get_file_age_in_seconds(pathlib.Path(TEST_KEY_NAME))
+        if cert_age < CERT_EXPIRY_AGE and key_age < CERT_EXPIRY_AGE:
+            logging.debug('Credentials are up to date...')
+            return
+
+        logging.debug('Credentials out of date, generating new ones...')
+        subprocess.check_output(
+            [
+                cls.build_paths.cast_receiver,
+                '-g',  # Generate certificate and private key.
+                '-v'  # Enable verbose logging.
+            ],
+            stderr=subprocess.STDOUT)
+
+    def launch_receiver(self):
+        """Launches the receiver process with discovery disabled."""
+        logging.debug('Launching the receiver application...')
+        loopback = _get_loopback_adapter_name()
+        self.assertTrue(loopback)
+
+        #pylint: disable = consider-using-with
+        return subprocess.Popen(
+            [
+                self.build_paths.cast_receiver,
+                '-d',
+                TEST_CERT_NAME,
+                '-p',
+                TEST_KEY_NAME,
+                '-x',  # Skip discovery, only necessary on Mac OS X.
+                '-v',  # Enable verbose logging.
+                loopback
+            ],
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE)
+
+    def launch_sender(self, flags):
+        """Launches the sender process, running the test video file once."""
+        logging.debug('Launching the sender application...')
+        command = [
+            self.build_paths.cast_sender,
+            '127.0.0.1:8010',
+            self.build_paths.test_video,
+            '-d',
+            TEST_CERT_NAME,
+            '-n'  # Only play the video once, and then exit.
+        ]
+        if TestFlags.UseAndroidHack in flags:
+            command.append('-a')
+        if TestFlags.UseRemoting in flags:
+            command.append('-r')
+
+        #pylint: disable = consider-using-with
+        return subprocess.Popen(command,
+                                stdout=subprocess.PIPE,
+                                stderr=subprocess.PIPE)
+
+    def check_logs(self, logs):
+        """Checks that the outputted logs contain expected behavior."""
+        for message in EXPECTED_RECEIVER_MESSAGES:
+            self.assertTrue(
+                message in logs[0],
+                'Missing log message: {}.\n{}'.format(message,
+                                                      MISSING_LOG_MESSAGE))
+        for message in EXPECTED_SENDER_MESSAGES:
+            self.assertTrue(
+                message in logs[1],
+                'Missing log message: {}.\n{}'.format(message,
+                                                      MISSING_LOG_MESSAGE))
+        for log, prefix in logs, ["[ERROR:", "[FATAL:"]:
+            self.assertTrue(prefix not in log, "Logs contained an error")
+        logging.debug('Finished validating log output')
+
+    def get_output(self, flags):
+        """Launches the sender and receiver, and handles exit output."""
+        receiver_process = self.launch_receiver()
+        logging.debug('Letting the receiver start up...')
+        time.sleep(3)
+        sender_process = self.launch_sender(flags)
+
+        logging.debug('Launched sender PID %i and receiver PID %i...',
+            sender_process.pid, receiver_process.pid)
+        logging.debug('collating output...')
+        output = (receiver_process.communicate(
+            timeout=PROCESS_TIMEOUT)[1].decode('utf-8'),
+                  sender_process.communicate(
+                      timeout=PROCESS_TIMEOUT)[1].decode('utf-8'))
+
+        # TODO(issuetracker.google.com/194292855): standalones should exit zero.
+        # Remoting causes the sender to exit with code -4.
+        if not TestFlags.UseRemoting in flags:
+            self.assertEqual(sender_process.returncode, 0,
+                             'sender had non-zero exit code')
+        return output
+
+    def test_golden_case(self):
+        """Tests that when settings are normal, things work end to end."""
+        output = self.get_output([])
+        self.check_logs(output)
+
+    def test_remoting(self):
+        """Tests that basic remoting works."""
+        output = self.get_output(TestFlags.UseRemoting)
+        self.check_logs(output)
+
+    def test_with_android_hack(self):
+        """Tests that things work when the Android RTP hack is enabled."""
+        output = self.get_output(TestFlags.UseAndroidHack)
+        self.check_logs(output)
+
+
+def parse_args():
+    """Parses the command line arguments and sets up the logging module."""
+    # NOTE for future developers: the `unittest` module will complain if it is
+    # passed any args that it doesn't understand. If any Open Screen-specific
+    # command line arguments are added in the future, they should be cropped
+    # from sys.argv before |unittest.main()| is called.
+    parser = argparse.ArgumentParser(description=DESCRIPTION)
+    parser.add_argument('-v',
+                        '--verbose',
+                        help='enable debug logging',
+                        action='store_true')
+
+    parsed_args = parser.parse_args(sys.argv[1:])
+    _set_log_level(parsed_args.verbose)
+
+
+if __name__ == '__main__':
+    parse_args()
+    unittest.main()
diff --git a/cast/standalone_receiver/streaming_playback_controller.cc b/cast/standalone_receiver/streaming_playback_controller.cc
index 4a81c7ed..5f6412a4 100644
--- a/cast/standalone_receiver/streaming_playback_controller.cc
+++ b/cast/standalone_receiver/streaming_playback_controller.cc
@@ -89,6 +89,7 @@ void StreamingPlaybackController::OnRemotingNegotiated(
 void StreamingPlaybackController::OnReceiversDestroying(
     const ReceiverSession* session,
     ReceiversDestroyingReason reason) {
+  OSP_LOG_INFO << "Receivers are currently destroying, resetting SDL players.";
   audio_player_.reset();
   video_player_.reset();
 }
@@ -101,6 +102,7 @@ void StreamingPlaybackController::OnError(const ReceiverSession* session,
 void StreamingPlaybackController::Initialize(
     ReceiverSession::ConfiguredReceivers receivers) {
 #if defined(CAST_STANDALONE_RECEIVER_HAVE_EXTERNAL_LIBS)
+  OSP_LOG_INFO << "Successfully negotiated a session, creating SDL players.";
   if (receivers.audio_receiver) {
     audio_player_ = std::make_unique<SDLAudioPlayer>(
         &Clock::now, task_runner_, receivers.audio_receiver,
diff --git a/cast/streaming/remoting_capabilities.h b/cast/streaming/remoting_capabilities.h
index 6957028f..a2f7b173 100644
--- a/cast/streaming/remoting_capabilities.h
+++ b/cast/streaming/remoting_capabilities.h
@@ -37,7 +37,8 @@ enum class VideoCapability {
   kH264,
   kVp8,
   kVp9,
-  kHevc
+  kHevc,
+  kAv1
 };
 
 // This class is similar to the RemotingSinkMetadata in Chrome, however
diff --git a/cast/streaming/sender_session.cc b/cast/streaming/sender_session.cc
index cae6f3e4..c47e9667 100644
--- a/cast/streaming/sender_session.cc
+++ b/cast/streaming/sender_session.cc
@@ -186,6 +186,9 @@ RemotingCapabilities ToCapabilities(const ReceiverCapability& capability) {
       case MediaCapability::kHevc:
         out.video.push_back(VideoCapability::kHevc);
         break;
+      case MediaCapability::kAv1:
+        out.video.push_back(VideoCapability::kAv1);
+        break;
       case MediaCapability::kVideo:
         // noop, as "video" is ignored by Chrome remoting.
         break;