chromedriver.py revision 8949a8db9cd4d16f897d88241dfc0d658cf93d44 
1# Copyright (c) 2013 The Chromium OS 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
5import atexit
6import logging
7import os
8import urllib2
9import urlparse
10
11try:
12    from selenium import webdriver
13except ImportError:
14    # Ignore import error, as this can happen when builder tries to call the
15    # setup method of test that imports chromedriver.
16    logging.error('selenium module failed to be imported.')
17    pass
18
19from autotest_lib.client.bin import utils
20from autotest_lib.client.common_lib.cros import chrome
21
22CHROMEDRIVER_EXE_PATH = '/usr/local/chromedriver/chromedriver'
23X_SERVER_DISPLAY = ':0'
24X_AUTHORITY = '/home/chronos/.Xauthority'
25
26
27class chromedriver(object):
28    """Wrapper class, a context manager type, for tests to use Chrome Driver."""
29
30    def __init__(self, extra_chrome_flags=[], subtract_extra_chrome_flags=[],
31                 extension_paths=[], username=None, password=None,
32                 server_port=None, skip_cleanup=False, url_base=None,
33                 extra_chromedriver_args=None, *args, **kwargs):
34        """Initialize.
35
36        @param extra_chrome_flags: Extra chrome flags to pass to chrome, if any.
37        @param subtract_extra_chrome_flags: Remove default flags passed to
38                chrome by chromedriver, if any.
39        @param extension_paths: A list of paths to unzipped extensions. Note
40                                that paths to crx files won't work.
41        @param username: Log in using this username instead of the default.
42        @param password: Log in using this password instead of the default.
43        @param server_port: Port number for the chromedriver server. If None,
44                            an available port is chosen at random.
45        @param skip_cleanup: If True, leave the server and browser running
46                             so that remote tests can run after this script
47                             ends. Default is False.
48        @param url_base: Optional base url for chromedriver.
49        @param extra_chromedriver_args: List of extra arguments to forward to
50                                        the chromedriver binary, if any.
51        """
52        self._cleanup = not skip_cleanup
53        assert os.geteuid() == 0, 'Need superuser privileges'
54
55        # Log in with telemetry
56        self._chrome = chrome.Chrome(extension_paths=extension_paths,
57                                     username=username,
58                                     password=password,
59                                     extra_browser_args=extra_chrome_flags)
60        self._browser = self._chrome.browser
61        # Close all tabs owned and opened by Telemetry, as these cannot be
62        # transferred to ChromeDriver.
63        self._browser.tabs[0].Close()
64
65        # Start ChromeDriver server
66        self._server = chromedriver_server(CHROMEDRIVER_EXE_PATH,
67                                           port=server_port,
68                                           skip_cleanup=skip_cleanup,
69                                           url_base=url_base,
70                                           extra_args=extra_chromedriver_args)
71
72        # Open a new tab using Chrome remote debugging. ChromeDriver expects
73        # a tab opened for remote to work. Tabs opened using Telemetry will be
74        # owned by Telemetry, and will be inaccessible to ChromeDriver.
75        urllib2.urlopen('http://localhost:%i/json/new' %
76                        utils.get_chrome_remote_debugging_port())
77
78        chromeOptions = {'debuggerAddress':
79                         ('localhost:%d' %
80                          utils.get_chrome_remote_debugging_port())}
81        capabilities = {'chromeOptions':chromeOptions}
82        # Handle to chromedriver, for chrome automation.
83        try:
84            self.driver = webdriver.Remote(command_executor=self._server.url,
85                                           desired_capabilities=capabilities)
86        except NameError:
87            logging.error('selenium module failed to be imported.')
88            raise
89
90
91    def __enter__(self):
92        return self
93
94
95    def __exit__(self, *args):
96        """Clean up after running the test.
97
98        """
99        if hasattr(self, 'driver') and self.driver:
100            self.driver.close()
101            del self.driver
102
103        if not hasattr(self, '_cleanup') or self._cleanup:
104            if hasattr(self, '_server') and self._server:
105                self._server.close()
106                del self._server
107
108            if hasattr(self, '_browser') and self._browser:
109                self._browser.Close()
110                del self._browser
111
112    def get_extension(self, extension_path):
113        """Gets an extension by proxying to the browser.
114
115        @param extension_path: Path to the extension loaded in the browser.
116
117        @return: A telemetry extension object representing the extension.
118        """
119        return self._chrome.get_extension(extension_path)
120
121
122    @property
123    def chrome_instance(self):
124        """ The chrome instance used by this chrome driver instance. """
125        return self._chrome
126
127
128class chromedriver_server(object):
129    """A running ChromeDriver server.
130
131    This code is migrated from chrome:
132    src/chrome/test/chromedriver/server/server.py
133    """
134
135    def __init__(self, exe_path, port=None, skip_cleanup=False,
136                 url_base=None, extra_args=None):
137        """Starts the ChromeDriver server and waits for it to be ready.
138
139        Args:
140            exe_path: path to the ChromeDriver executable
141            port: server port. If None, an available port is chosen at random.
142            skip_cleanup: If True, leave the server running so that remote
143                          tests can run after this script ends. Default is
144                          False.
145            url_base: Optional base url for chromedriver.
146            extra_args: List of extra arguments to forward to the chromedriver
147                        binary, if any.
148        Raises:
149            RuntimeError if ChromeDriver fails to start
150        """
151        if not os.path.exists(exe_path):
152            raise RuntimeError('ChromeDriver exe not found at: ' + exe_path)
153
154        chromedriver_args = [exe_path]
155        if port:
156            # Allow remote connections if a port was specified
157            chromedriver_args.append('--whitelisted-ips')
158        else:
159            port = utils.get_unused_port()
160        chromedriver_args.append('--port=%d' % port)
161
162        self.url = 'http://localhost:%d' % port
163        if url_base:
164            chromedriver_args.append('--url-base=%s' % url_base)
165            self.url = urlparse.urljoin(self.url, url_base)
166
167        if extra_args:
168            chromedriver_args.extend(extra_args)
169
170        # TODO(ihf): Remove references to X after M45.
171        # Chromedriver will look for an X server running on the display
172        # specified through the DISPLAY environment variable.
173        os.environ['DISPLAY'] = X_SERVER_DISPLAY
174        os.environ['XAUTHORITY'] = X_AUTHORITY
175
176        self.bg_job = utils.BgJob(chromedriver_args, stderr_level=logging.DEBUG)
177        if self.bg_job is None:
178            raise RuntimeError('ChromeDriver server cannot be started')
179
180        try:
181            timeout_msg = 'Timeout on waiting for ChromeDriver to start.'
182            utils.poll_for_condition(self.is_running,
183                                     exception=utils.TimeoutError(timeout_msg),
184                                     timeout=10,
185                                     sleep_interval=.1)
186        except utils.TimeoutError:
187            self.close_bgjob()
188            raise RuntimeError('ChromeDriver server did not start')
189
190        logging.debug('Chrome Driver server is up and listening at port %d.',
191                      port)
192        if not skip_cleanup:
193            atexit.register(self.close)
194
195
196    def is_running(self):
197        """Returns whether the server is up and running."""
198        try:
199            urllib2.urlopen(self.url + '/status')
200            return True
201        except urllib2.URLError as e:
202            return False
203
204
205    def close_bgjob(self):
206        """Close background job and log stdout and stderr."""
207        utils.nuke_subprocess(self.bg_job.sp)
208        utils.join_bg_jobs([self.bg_job], timeout=1)
209        result = self.bg_job.result
210        if result.stdout or result.stderr:
211            logging.info('stdout of Chrome Driver:\n%s', result.stdout)
212            logging.error('stderr of Chrome Driver:\n%s', result.stderr)
213
214
215    def close(self):
216        """Kills the ChromeDriver server, if it is running."""
217        if self.bg_job is None:
218            return
219
220        try:
221            urllib2.urlopen(self.url + '/shutdown', timeout=10).close()
222        except:
223            pass
224
225        self.close_bgjob()
226