app/maillogger.py

   1 import logging
   2 from enum import Enum
   3 from app.tasks.emails import sendEmailRaw
   4
   5 def _has_newline(line):
   6         """Used by has_bad_header to check for \\r or \\n"""
   7         if line and ("\r" in line or "\n" in line):
   8                 return True
   9         return False
  10
  11 def _is_bad_subject(subject):
  12         """Copied from: flask_mail.py class Message def has_bad_headers"""
  13         if _has_newline(subject):
  14                 for linenum, line in enumerate(subject.split("\r\n")):
  15                         if not line:
  16                                 return True
  17                         if linenum > 0 and line[0] not in "\t ":
  18                                 return True
  19                         if _has_newline(line):
  20                                 return True
  21                         if len(line.strip()) == 0:
  22                                 return True
  23         return False
  24
  25
  26 class FlaskMailSubjectFormatter(logging.Formatter):
  27         def format(self, record):
  28                 record.message = record.getMessage()
  29                 if self.usesTime():
  30                         record.asctime = self.formatTime(record, self.datefmt)
  31                 s = self.formatMessage(record)
  32                 return s
  33
  34 class FlaskMailTextFormatter(logging.Formatter):
  35         pass
  36
  37 # TODO: hier nog niet tevreden over (vooral logger.error(..., exc_info, stack_info))
  38 class FlaskMailHTMLFormatter(logging.Formatter):
  39         pre_template = "<h1>%s</h1><pre>%s</pre>"
  40         def formatException(self, exc_info):
  41                 formatted_exception = logging.Handler.formatException(self, exc_info)
  42                 return FlaskMailHTMLFormatter.pre_template % ("Exception information", formatted_exception)
  43         def formatStack(self, stack_info):
  44                 return FlaskMailHTMLFormatter.pre_template % ("<h1>Stack information</h1><pre>%s</pre>", stack_info)
  45
  46
  47 # see: https://github.com/python/cpython/blob/3.6/Lib/logging/__init__.py (class Handler)
  48
  49 class FlaskMailHandler(logging.Handler):
  50         def __init__(self, mailer, subject_template, level=logging.NOTSET):
  51                 logging.Handler.__init__(self, level)
  52                 self.mailer = mailer
  53                 self.send_to = mailer.app.config["MAIL_UTILS_ERROR_SEND_TO"]
  54                 self.subject_template = subject_template
  55                 self.html_formatter = None
  56
  57         def setFormatter(self, text_fmt, html_fmt=None):
  58                 """
  59                 Set the formatters for this handler. Provide at least one formatter.
  60                 When no text_fmt is provided, no text-part is created for the email body.
  61                 """
  62                 assert (text_fmt, html_fmt) != (None, None), "At least one formatter should be provided"
  63                 if type(text_fmt)==str:
  64                         text_fmt = FlaskMailTextFormatter(text_fmt)
  65                 self.formatter = text_fmt
  66                 if type(html_fmt)==str:
  67                         html_fmt = FlaskMailHTMLFormatter(html_fmt)
  68                 self.html_formatter = html_fmt
  69
  70         def getSubject(self, record):
  71                 fmt = FlaskMailSubjectFormatter(self.subject_template)
  72                 subject = fmt.format(record)
  73                 #Since templates can cause header problems, and we rather have a incomplete email then an error, we fix this
  74                 if _is_bad_subject(subject):
  75                         subject="FlaskMailHandler log-entry from %s [original subject is replaced, because it would result in a bad header]" % self.mailer.app.name
  76                 return subject
  77
  78         def emit(self, record):
  79                 text = self.format(record)                              if self.formatter         else None
  80                 html = self.html_formatter.format(record) if self.html_formatter else None
  81                 sendEmailRaw.delay(self.send_to, self.getSubject(record), text, html)
  82
  83
  84 def register_mail_error_handler(app, mailer):
  85         subject_template = "ContentDB crashed (%(module)s > %(funcName)s)"
  86         text_template = """
  87 Message type: %(levelname)s
  88 Location:        %(pathname)s:%(lineno)d
  89 Module:    %(module)s
  90 Function:        %(funcName)s
  91 Time:            %(asctime)s
  92 Message:
  93 %(message)s"""
  94         html_template = """
  95 <style>th { text-align: right}</style><table>
  96 <tr><th>Message type:</th><td>%(levelname)s</td></tr>
  97 <tr>    <th>Location:</th><td>%(pathname)s:%(lineno)d</td></tr>
  98 <tr>      <th>Module:</th><td>%(module)s</td></tr>
  99 <tr>    <th>Function:</th><td>%(funcName)s</td></tr>
 100 <tr>            <th>Time:</th><td>%(asctime)s</td></tr>
 101 </table>
 102 <h2>Message</h2>
 103 <pre>%(message)s</pre>"""
 104
 105         import logging
 106         mail_handler = FlaskMailHandler(mailer, subject_template)
 107         mail_handler.setLevel(logging.ERROR)
 108         mail_handler.setFormatter(text_template, html_template)
 109         app.logger.addHandler(mail_handler)