1#!/usr/bin/python
2# Copyright 2015 The Chromium OS Authors. All rights reserved.
3# Use of this source code is governed by a BSD-style license that can be
4# found in the LICENSE file.
5
6"""
7Mail the content of standard input.
8
9Example usage:
10  Use pipe:
11     $ echo "Some content" |./gmail_lib.py -s "subject" abc@bb.com xyz@gmail.com
12
13  Manually input:
14     $ ./gmail_lib.py -s "subject" abc@bb.com xyz@gmail.com
15     > Line 1
16     > Line 2
17     Ctrl-D to end standard input.
18"""
19import argparse
20import base64
21import httplib2
22import logging
23import sys
24import os
25from email.mime.text import MIMEText
26
27import common
28from autotest_lib.client.common_lib import global_config
29from autotest_lib.client.common_lib.cros.graphite import autotest_stats
30from autotest_lib.server import utils as server_utils
31from chromite.lib import retry_util
32
33try:
34  from apiclient.discovery import build as apiclient_build
35  from apiclient import errors as apiclient_errors
36  from oauth2client import file as oauth_client_fileio
37except ImportError as e:
38  apiclient_build = None
39  logging.debug("API client for gmail disabled. %s", e)
40
41
42EMAIL_COUNT_KEY = 'emails.%s'
43DEFAULT_CREDS_FILE = global_config.global_config.get_config_value(
44        'NOTIFICATIONS', 'gmail_api_credentials', default=None)
45RETRY_DELAY = 5
46RETRY_BACKOFF_FACTOR = 1.5
47MAX_RETRY = 10
48RETRIABLE_MSGS = [
49        # User-rate limit exceeded
50        r'HttpError 429',]
51
52class GmailApiException(Exception):
53    """Exception raised in accessing Gmail API."""
54
55
56class Message():
57    """An email message."""
58
59    def __init__(self, to, subject, message_text):
60        """Initialize a message.
61
62        @param to: The recievers saperated by comma.
63                   e.g. 'abc@gmail.com,xyz@gmail.com'
64        @param subject: String, subject of the message
65        @param message_text: String, content of the message.
66        """
67        self.to = to
68        self.subject = subject
69        self.message_text = message_text
70
71
72    def get_payload(self):
73        """Get the payload that can be sent to the Gmail API.
74
75        @return: A dictionary representing the message.
76        """
77        message = MIMEText(self.message_text)
78        message['to'] = self.to
79        message['subject'] = self.subject
80        return {'raw': base64.urlsafe_b64encode(message.as_string())}
81
82
83class GmailApiClient():
84    """Client that talks to Gmail API."""
85
86    def __init__(self, oauth_credentials):
87        """Init Gmail API client
88
89        @param oauth_credentials: Path to the oauth credential token.
90        """
91        if not apiclient_build:
92            raise GmailApiException('Cannot get apiclient library.')
93
94        storage = oauth_client_fileio.Storage(oauth_credentials)
95        credentials = storage.get()
96        if not credentials or credentials.invalid:
97            raise GmailApiException('Invalid credentials for Gmail API, '
98                                    'could not send email.')
99        http = credentials.authorize(httplib2.Http())
100        self._service = apiclient_build('gmail', 'v1', http=http)
101
102
103    def send_message(self, message, ignore_error=True):
104        """Send an email message.
105
106        @param message: Message to be sent.
107        @param ignore_error: If True, will ignore any HttpError.
108        """
109        try:
110            # 'me' represents the default authorized user.
111            message = self._service.users().messages().send(
112                    userId='me', body=message.get_payload()).execute()
113            logging.debug('Email sent: %s' , message['id'])
114        except apiclient_errors.HttpError as error:
115            if ignore_error:
116                logging.error('Failed to send email: %s', error)
117            else:
118                raise
119
120
121def send_email(to, subject, message_text, retry=True, creds_path=None):
122    """Send email.
123
124    @param to: The recipients, separated by comma.
125    @param subject: Subject of the email.
126    @param message_text: Text to send.
127    @param retry: If retry on retriable failures as defined in RETRIABLE_MSGS.
128    @param creds_path: The credential path for gmail account, if None,
129                       will use DEFAULT_CREDS_FILE.
130    """
131    auth_creds = server_utils.get_creds_abspath(
132        creds_path or DEFAULT_CREDS_FILE)
133    if not auth_creds or not os.path.isfile(auth_creds):
134        logging.error('Failed to send email to %s: Credential file does not'
135                      'exist: %s. If this is a prod server, puppet should'
136                      'install it. If you need to be able to send email, '
137                      'find the credential file from chromeos-admin repo and '
138                      'copy it to %s', to, auth_creds, auth_creds)
139        return
140    client = GmailApiClient(oauth_credentials=auth_creds)
141    m = Message(to, subject, message_text)
142    retry_count = MAX_RETRY if retry else 0
143
144    def _run():
145        """Send the message."""
146        client.send_message(m, ignore_error=False)
147
148    def handler(exc):
149        """Check if exc is an HttpError and is retriable.
150
151        @param exc: An exception.
152
153        @return: True if is an retriable HttpError.
154        """
155        if not isinstance(exc, apiclient_errors.HttpError):
156            return False
157
158        error_msg = str(exc)
159        should_retry = any([msg in error_msg for msg in RETRIABLE_MSGS])
160        if should_retry:
161            logging.warning('Will retry error %s', exc)
162        return should_retry
163
164    autotest_stats.Counter(EMAIL_COUNT_KEY % 'total').increment()
165    try:
166        retry_util.GenericRetry(
167                handler, retry_count, _run, sleep=RETRY_DELAY,
168                backoff_factor=RETRY_BACKOFF_FACTOR)
169    except Exception:
170        autotest_stats.Counter(EMAIL_COUNT_KEY % 'fail').increment()
171        raise
172
173
174if __name__ == '__main__':
175    logging.basicConfig(level=logging.DEBUG)
176    parser = argparse.ArgumentParser(
177            description=__doc__, formatter_class=argparse.RawTextHelpFormatter)
178    parser.add_argument('-s', '--subject', type=str, dest='subject',
179                        required=True, help='Subject of the mail')
180    parser.add_argument('recipients', nargs='*',
181                        help='Email addresses separated by space.')
182    args = parser.parse_args()
183    if not args.recipients or not args.subject:
184        print 'Requires both recipients and subject.'
185        sys.exit(1)
186
187    message_text = sys.stdin.read()
188    send_email(','.join(args.recipients), args.subject , message_text)
189