Sindbad~EG File Manager

# -*- coding: utf-8 -*-

# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2018 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# http://cloudlinux.com/docs/LICENSE.TXT
#


from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import logging
from logging.handlers import SysLogHandler
import smtplib
import subprocess
import os
from _socket import error as socketerror


__author__ = "Aleksandr Shyshatsky"


class MailSendFailed(Exception):
    pass


class MailHelper:
    def __init__(self):
        if not logging.root.handlers:
            if os.path.exists('/dev/log'):
                SYS_LOG = SysLogHandler(address='/dev/log', facility=SysLogHandler.LOG_DAEMON)
                logging.root.addHandler(SYS_LOG)
                formatter_sys = logging.Formatter(fmt='mail_helper: (%(name)s) [%(levelname)s] %(message)s')
                SYS_LOG.setFormatter(formatter_sys)  # write in system log only ERROR-s and FATALLERROR-s
                SYS_LOG.setLevel(logging.ERROR)
            else:
                logging.basicConfig()
        self._log = logging.getLogger()

    def _sendmail_console(self, msg, encoding_name: str = None):
        """
        Alternative function that should be called
        when we cannot send email via smtp
        :type msg: email.mime.base.MIMEBase 
        :type encoding_name: encoding name to encode message text
        """
        try:
            if encoding_name:
                s_message = msg.as_string().encode(encoding_name)
            else:
                s_message = msg.as_string()
            cmd = ["/usr/sbin/sendmail", "-t", "-oi"]
            p = subprocess.Popen(cmd, stdin=subprocess.PIPE,
                                 stdout=subprocess.PIPE,
                                 stderr=subprocess.PIPE,
                                 text=True)
            stdout = p.communicate(s_message)[0]
            if p.returncode != 0:
                raise subprocess.CalledProcessError(p.returncode, cmd, stdout)

        except (OSError, subprocess.CalledProcessError) as ex:
            raise MailSendFailed(str(ex))

    def _sendmail_smtp(self, from_addr, to_addrs, msg, encoding_name: str = None):
        """
        Send email using smtp protocol; 
        :type from_addr: str
        :type to_addrs: list 
        :type msg: email.mime.base.MIMEBase
        :type encoding_name: encoding name to encode message text
        """
        try:
            smtp_instance = smtplib.SMTP('localhost')
            if encoding_name:
                s_message = msg.as_string().encode(encoding_name)
            else:
                s_message = msg.as_string()
            smtp_instance.sendmail(from_addr, to_addrs, s_message)
            smtp_instance.quit()
        except (smtplib.SMTPException, socketerror) as ex:
            raise MailSendFailed(str(ex))

    def sendmail(self, from_addr, to_addrs, msg, encoding_name: str = None):
        """
        Try to send message using local smtp;
        If that can't be done - try to use /usr/sbin/sendmail;
        :type from_addr: str
        :type to_addrs: list 
        :type msg: MIMEMultipart
        :type encoding_name: encoding name to encode message text
        """
        self._log.debug("Trying to send mail with params: %s, %s, %s", from_addr, to_addrs, msg)
        try:
            self._sendmail_smtp(from_addr, to_addrs, msg, encoding_name)
        except MailSendFailed as smtp_exception:
            self._log.debug("Smtp send failed, trying to send via sendmail")
            try:
                self._sendmail_console(msg)
            except MailSendFailed:
                self._log.exception("Cannot send email neither via smtp nor using sendmail; "
                                    "Please, check your mail server configuration")
                self._log.error(str(smtp_exception))