add: first implementation of the logging handlers

redmail/__init__.py

@@ -1,3 +1,4 @@
 from .email import EmailSender, send_email, gmail
+from .log import EmailHandler, MultiEmailHandler
 from . import _version
 __version__ = _version.get_versions()['version']

redmail/log.py

@@ -0,0 +1,234 @@
+
+import logging
+from logging import Handler, LogRecord
+from logging.handlers import SMTPHandler, BufferingHandler
+from textwrap import dedent
+from typing import List
+
+from redmail.email.sender import EmailSender
+
+class _EmailHandlerMixin:
+
+    def set_sender(self, 
+                   host, port, 
+                   user_name=None, password=None, 
+                   sender=None, receivers=None,
+                   subject=None):
+        "Create a simple default sender"
+        self.sender = EmailSender(
+            host=host, port=port,
+            user_name=user_name, password=password
+        )
+        self.sender.receivers = receivers
+        self.sender.sender = sender
+        if receivers is not None:
+            self.sender.receivers = receivers
+        elif user_name is not None:
+            self.sender.receivers = user_name
+        else:
+            raise ValueError("Missing receiver")
+        
+        self.sender.text = self.default_text
+        self.sender.subject = subject or "Log record"
+
+    def get_subject(self, record):
+        "Get subject of the email"
+        if self.fmt_subject is not None:
+            return self.fmt_subject.format(
+                record=record, handler=self
+            )
+
+
+class EmailHandler(_EmailHandlerMixin, Handler):
+    """Logging handler for sending a log record as an email
+
+    Parameters
+    ----------
+    level : int
+        Log level of the handler
+    sender : EmailSender
+        Sender instance to be used for sending
+        the log records.
+    fmt_subject : str, optional
+        Format of the email subject. ``record``
+        is passed as a format argument.
+    kwargs : dict
+        Keyword arguments for creating the 
+        sender if ``sender`` was not passed.
+
+    Examples
+    --------
+
+        Minimal example:
+
+        .. code-block:: python
+
+            handler = EmailHandler(
+                host="smtp.myhost.com", port=0,
+                fmt_subject="Log: {record.levelname}",
+                sender="no-reply@example.com",
+                receivers=["me@example.com"],
+            )
+
+        Customized example:
+
+        .. code-block:: python
+
+            from redmail import EmailSender
+            email = EmailSender(
+                host="smtp.myhost.com",
+                port=0
+            )
+            email.sender = "no-reply@example.com"
+            email.receivers = ["me@example.com"]
+            email.html = '''
+                <h1>Record: {{ record.levelname }}</h1>
+                <pre>{{ record.msg }}</pre>
+                <h2>Info</h2>
+                <ul>
+                    <li>Path: {{ record.pathname }}</li>
+                    <li>Function: {{ record.funcName }}</li>
+                    <li>Line number: {{ record.lineno }}</li>
+                </ul>
+            '''
+            handler = EmailHandler(sender=email, fmt_subject="{record.name}}: {record.levelname}")
+
+            import logging
+            logger = logging.getLogger()
+            logger.addHandler(handler)
+    """
+
+    def __init__(self, level:int=logging.NOTSET, sender:EmailSender=None, fmt_subject=None, **kwargs):
+        super().__init__(level)
+        if sender is not None:
+            self.sender = sender
+        else:
+            self.set_sender(**kwargs)
+        self.fmt_subject = fmt_subject
+
+    default_text = "{{ msg }}"
+
+    def emit(self, record:logging.LogRecord):
+        "Emit a record"
+
+        self.sender.send(
+            subject=self.get_subject(record),
+            body_params={
+                "record": record,
+                "msg": self.format(record),
+                "handler": self,
+            }
+        )
+
+
+class MultiEmailHandler(_EmailHandlerMixin, BufferingHandler):
+    """Logging handler for sending multiple log records as an email
+
+    Parameters
+    ----------
+    capacity : int
+        Number of 
+    sender : EmailSender
+        Sender instance to be used for sending
+        the log records.
+    fmt_subject : str, optional
+        Format of the email subject. ``record``
+        is passed as a format argument.
+    kwargs : dict
+        Keyword arguments for creating the 
+        sender if ``sender`` was not passed.
+
+    Examples
+    --------
+
+        Minimal example:
+
+        .. code-block:: python
+
+            handler = MultiEmailHandler(
+                host="smtp.myhost.com", port=0,
+                fmt_subject="Log: {min_level_name} - {max_level_name}",
+                sender="no-reply@example.com",
+                receivers=["me@example.com"],
+            )
+
+        Customized example:
+
+        .. code-block:: python
+
+            from redmail import EmailSender
+            email = EmailSender(
+                host="smtp.myhost.com",
+                port=0
+            )
+            email.sender = "no-reply@example.com"
+            email.receivers = ["me@example.com"]
+            email.html = '''
+                <h1>Record: {{ record.levelname }}</h1>
+                <pre>{{ record.msg }}</pre>
+                <h2>Info</h2>
+                <ul>
+                    <li>Path: {{ record.pathname }}</li>
+                    <li>Function: {{ record.funcName }}</li>
+                    <li>Line number: {{ record.lineno }}</li>
+                </ul>
+            '''
+            handler = EmailHandler(sender=email, fmt_subject="{record.name}}: {record.levelname}")
+
+            import logging
+            logger = logging.getLogger()
+            logger.addHandler(handler)
+    """
+
+    default_text = dedent("""
+    {% for record in records -%}
+    Log Record
+    ----------------------------
+    {% set msg = handler.format(record) -%}
+    {{ msg }}
+
+
+    {% endfor %}""")[1:]
+
+    def __init__(self, capacity:int, sender:EmailSender=None, fmt_subject=None, **kwargs):
+        super().__init__(capacity)
+        if sender is not None:
+            self.sender = sender
+        else:
+            self.set_sender(**kwargs)
+        self.fmt_subject = fmt_subject
+
+    def flush(self):
+        "Flush (send) the records"
+        self.acquire()
+        try:
+            
+            for rec in self.buffer:
+            # This creates msg, exc_text etc. to LogRecords
+                self.format(rec)
+                # For some reason logging does not create this attr unless having asctime in the format string
+                if self.formatter is None:
+                    rec.asctime = logging.Formatter().formatTime(rec)
+
+            self.sender.send(
+                subject=self.get_subject(self.buffer),
+                body_params={
+                    "records": self.buffer,
+                    "handler": self
+                }
+            )
+            self.buffer = []
+        finally:
+            self.release()
+
+    def get_subject(self, records:List[LogRecord]):
+        "Get subject of the email"
+        if self.fmt_subject is not None:
+            min_level = min([record.levelno for record in records])
+            max_level = max([record.levelno for record in records])
+            return self.fmt_subject.format(
+                min_level_name=logging.getLevelName(min_level), 
+                max_level_name=logging.getLevelName(max_level),
+                handler=self,
+                records=records
+            )