1 # Copyright 2012 The Chromium Authors. All rights reserved. 2 # Use of this source code is governed by a BSD-style license that can be 3 # found in the LICENSE file. 4 5 """Start and stop Web Page Replay. 6 7 Of the public module names, the following one is key: 8 ReplayServer: a class to start/stop Web Page Replay. 9 """ 10 11 import logging 12 import os 13 import re 14 import signal 15 import subprocess 16 import sys 17 import urllib 18 19 from telemetry.core import util 20 21 _CHROME_SRC_DIR = os.path.abspath(os.path.join( 22 os.path.dirname(__file__), os.pardir, os.pardir, os.pardir, os.pardir)) 23 REPLAY_DIR = os.path.join( 24 _CHROME_SRC_DIR, 'third_party', 'webpagereplay') 25 LOG_PATH = os.path.join( 26 _CHROME_SRC_DIR, 'webpagereplay_logs', 'logs.txt') 27 28 29 # Chrome options to make it work with Web Page Replay. 30 def GetChromeFlags(replay_host, http_port, https_port): 31 assert replay_host and http_port and https_port, 'All arguments required' 32 return [ 33 '--host-resolver-rules=MAP * %s,EXCLUDE localhost' % replay_host, 34 '--testing-fixed-http-port=%s' % http_port, 35 '--testing-fixed-https-port=%s' % https_port, 36 '--ignore-certificate-errors', 37 ] 38 39 40 # Signal masks on Linux are inherited from parent processes. If anything 41 # invoking us accidentally masks SIGINT (e.g. by putting a process in the 42 # background from a shell script), sending a SIGINT to the child will fail 43 # to terminate it. Running this signal handler before execing should fix that 44 # problem. 45 def ResetInterruptHandler(): 46 signal.signal(signal.SIGINT, signal.SIG_DFL) 47 48 49 class ReplayError(Exception): 50 """Catch-all exception for the module.""" 51 pass 52 53 54 class ReplayNotFoundError(ReplayError): 55 def __init__(self, label, path): 56 super(ReplayNotFoundError, self).__init__() 57 self.args = (label, path) 58 59 def __str__(self): 60 label, path = self.args 61 return 'Path does not exist for %s: %s' % (label, path) 62 63 64 class ReplayNotStartedError(ReplayError): 65 pass 66 67 68 class ReplayServer(object): 69 """Start and Stop Web Page Replay. 70 71 Web Page Replay is a proxy that can record and "replay" web pages with 72 simulated network characteristics -- without having to edit the pages 73 by hand. With WPR, tests can use "real" web content, and catch 74 performance issues that may result from introducing network delays and 75 bandwidth throttling. 76 77 Example: 78 with ReplayServer(archive_path): 79 self.NavigateToURL(start_url) 80 self.WaitUntil(...) 81 82 Environment Variables (for development): 83 WPR_ARCHIVE_PATH: path to alternate archive file (e.g. '/tmp/foo.wpr'). 84 WPR_RECORD: if set, puts Web Page Replay in record mode instead of replay. 85 WPR_REPLAY_DIR: path to alternate Web Page Replay source. 86 """ 87 88 def __init__(self, archive_path, replay_host, dns_port, http_port, https_port, 89 replay_options=None, replay_dir=None, 90 log_path=None): 91 """Initialize ReplayServer. 92 93 Args: 94 archive_path: a path to a specific WPR archive (required). 95 replay_host: the hostname to serve traffic. 96 dns_port: an integer port on which to serve DNS traffic. May be zero 97 to let the OS choose an available port. If None DNS forwarding is 98 disabled. 99 http_port: an integer port on which to serve HTTP traffic. May be zero 100 to let the OS choose an available port. 101 https_port: an integer port on which to serve HTTPS traffic. May be zero 102 to let the OS choose an available port. 103 replay_options: an iterable of options strings to forward to replay.py. 104 replay_dir: directory that has replay.py and related modules. 105 log_path: a path to a log file. 106 """ 107 self.archive_path = os.environ.get('WPR_ARCHIVE_PATH', archive_path) 108 self.replay_options = list(replay_options or ()) 109 self.replay_dir = os.environ.get('WPR_REPLAY_DIR', replay_dir or REPLAY_DIR) 110 self.log_path = log_path or LOG_PATH 111 self.dns_port = dns_port 112 self.http_port = http_port 113 self.https_port = https_port 114 self._replay_host = replay_host 115 116 if 'WPR_RECORD' in os.environ and '--record' not in self.replay_options: 117 self.replay_options.append('--record') 118 self.is_record_mode = '--record' in self.replay_options 119 self._AddDefaultReplayOptions() 120 121 self.replay_py = os.path.join(self.replay_dir, 'replay.py') 122 123 if self.is_record_mode: 124 self._CheckPath('archive directory', os.path.dirname(self.archive_path)) 125 elif not os.path.exists(self.archive_path): 126 self._CheckPath('archive file', self.archive_path) 127 self._CheckPath('replay script', self.replay_py) 128 129 self.replay_process = None 130 131 def _AddDefaultReplayOptions(self): 132 """Set WPR command-line options. Can be overridden if needed.""" 133 self.replay_options = [ 134 '--host', str(self._replay_host), 135 '--port', str(self.http_port), 136 '--ssl_port', str(self.https_port), 137 '--use_closest_match', 138 '--no-dns_forwarding', 139 '--log_level', 'warning' 140 ] + self.replay_options 141 if self.dns_port is not None: 142 self.replay_options.extend(['--dns_port', str(self.dns_port)]) 143 144 def _CheckPath(self, label, path): 145 if not os.path.exists(path): 146 raise ReplayNotFoundError(label, path) 147 148 def _OpenLogFile(self): 149 log_dir = os.path.dirname(self.log_path) 150 if not os.path.exists(log_dir): 151 os.makedirs(log_dir) 152 return open(self.log_path, 'w') 153 154 def IsStarted(self): 155 """Checks to see if the server is up and running.""" 156 port_re = re.compile( 157 '.*?(?P<protocol>[A-Z]+) server started on (?P<host>.*):(?P<port>\d+)') 158 159 if self.replay_process.poll() is not None: 160 return False 161 162 # Read the ports from the WPR log. 163 if not self.http_port or not self.https_port or not self.dns_port: 164 with open(self.log_path) as f: 165 for line in f.readlines(): 166 m = port_re.match(line.strip()) 167 if m: 168 if not self.http_port and m.group('protocol') == 'HTTP': 169 self.http_port = int(m.group('port')) 170 elif not self.https_port and m.group('protocol') == 'HTTPS': 171 self.https_port = int(m.group('port')) 172 elif not self.dns_port and m.group('protocol') == 'DNS': 173 self.dns_port = int(m.group('port')) 174 175 # Try to connect to the WPR ports. 176 if self.http_port and self.https_port: 177 try: 178 up_url = '%s://%s:%s/web-page-replay-generate-200' 179 http_up_url = up_url % ('http', self._replay_host, self.http_port) 180 https_up_url = up_url % ('https', self._replay_host, self.https_port) 181 if (200 == urllib.urlopen(http_up_url, None, {}).getcode() and 182 200 == urllib.urlopen(https_up_url, None, {}).getcode()): 183 return True 184 except IOError: 185 pass 186 return False 187 188 def StartServer(self): 189 """Start Web Page Replay and verify that it started. 190 191 Raises: 192 ReplayNotStartedError: if Replay start-up fails. 193 """ 194 cmd_line = [sys.executable, self.replay_py] 195 cmd_line.extend(self.replay_options) 196 cmd_line.append(self.archive_path) 197 198 logging.debug('Starting Web-Page-Replay: %s', cmd_line) 199 with self._OpenLogFile() as log_fh: 200 kwargs = {'stdout': log_fh, 'stderr': subprocess.STDOUT} 201 if sys.platform.startswith('linux') or sys.platform == 'darwin': 202 kwargs['preexec_fn'] = ResetInterruptHandler 203 self.replay_process = subprocess.Popen(cmd_line, **kwargs) 204 205 try: 206 util.WaitFor(self.IsStarted, 30) 207 except util.TimeoutException: 208 with open(self.log_path) as f: 209 log = f.read() 210 raise ReplayNotStartedError( 211 'Web Page Replay failed to start. Log output:\n%s' % log) 212 213 def StopServer(self): 214 """Stop Web Page Replay.""" 215 if not self.replay_process: 216 return 217 218 logging.debug('Trying to stop Web-Page-Replay gracefully') 219 try: 220 urllib.urlopen('http://%s:%s/web-page-replay-command-exit' % ( 221 self._replay_host, self.http_port), None, {}).close() 222 except IOError: 223 # IOError is possible because the server might exit without response. 224 pass 225 226 try: 227 util.WaitFor(lambda: self.replay_process.poll() is not None, 10) 228 except util.TimeoutException: 229 try: 230 # Use a SIGINT so that it can do graceful cleanup. 231 self.replay_process.send_signal(signal.SIGINT) 232 except: # pylint: disable=W0702 233 # On Windows, we are left with no other option than terminate(). 234 if 'no-dns_forwarding' not in self.replay_options: 235 logging.warning('DNS configuration might not be restored!') 236 try: 237 self.replay_process.terminate() 238 except: # pylint: disable=W0702 239 pass 240 self.replay_process.wait() 241 242 def __enter__(self): 243 """Add support for with-statement.""" 244 self.StartServer() 245 return self 246 247 def __exit__(self, unused_exc_type, unused_exc_val, unused_exc_tb): 248 """Add support for with-statement.""" 249 self.StopServer() 250
