python logging: email entire log file as attachment when level >= ERROR

Question

My logging system has a few handlers, log file (INFO), an email handler (>ERROR), and a stream handler for optional debugging. When an error/exception/critical message occurs, I want the email handler to attach the log file from the file handler to the error email.

import logging

def initialize_logging():
    logger = logging.getLogger()
    logger.setLevel(logging.INFO)

    file_handler = createFileHandler()
    file_handler.setLevel(logging.INFO)
    logger.addHandler(file_handler)

    email_handler = createEmailHandler(file_handler.baseFilename)
    email_handler.setLevel(logging.ERROR)
    logger.addHandler(email_handler)

I found this example, but it's basically writing the handler from scratch. https://gist.github.com/LavinJ/238ccb229ac594a50b0a

I'd love if there was a simpler means of modifying the existing SMTPHandler

Answer 1

Looking at the source, it appears this is the easiest way to do it. Attaching the log file alone works well with this handler and the above code

class SMTPAttachmentHandler(logging.handlers.SMTPHandler):
    def __init__(self, mailhost, fromaddr, toaddrs, subject, credentials=None,
                 secure=None, attachment=None):
        super(SMTPAttachmentHandler, self).__init__(mailhost, fromaddr, toaddrs, subject,
                                                    credentials, secure)
        self.attachment = attachment

    def emit(self, record):
        if self.attachment is None or not os.path.isfile(self.attachment):
            return super(SMTPAttachmentHandler, self).emit(record)
        try:
            import smtplib
            from email.utils import formatdate
            from email.mime.text import MIMEText
            from email.mime.multipart import MIMEMultipart

            port = self.mailport
            if not port:
                port = smtplib.SMTP_PORT
            smtp = smtplib.SMTP(self.mailhost, port, timeout=self._timeout)

            msg = MIMEMultipart()
            msg['From'] = self.fromaddr
            msg['To'] = ",".join(self.toaddrs)
            msg['Date'] = formatdate()
            msg['Subject'] = self.getSubject(record)
            msg.attach(MIMEText(self.format(record).encode('utf-8'), 'html', 'utf-8'))

            dispo = 'attachment; filename="%s"' % os.path.basename(self.attachment)
            with open(self.attachment, "rb") as fd:
                attachment = MIMEText(fd.read())
                attachment.add_header("Content-Disposition", "attachment",
                                      filename=os.path.basename(self.attachment))
                msg.attach(attachment)

            if self.username:
                if self.secure is not None:
                    smtp.ehlo()
                    smtp.starttls(*self.secure)
                    smtp.ehlo()
                smtp.login(self.username, self.password)
            smtp.sendmail(self.fromaddr, self.toaddrs, msg.as_string())
            smtp.quit()
        except (KeyboardInterrupt, SystemExit):
            raise
        except:
            self.handleError(record)