improved logging

src/config-test.py

@@ -14,7 +14,6 @@
 # limitations under the License.
 #
 
-import traceback
 from datetime import datetime
 
 from imapclient import IMAPClient
@@ -23,24 +22,34 @@
 from lib import get_envelope_subject, \
     get_envelope_sender_first, \
     get_envelope_from_first, \
-    get_envelope_date
+    get_envelope_date, \
+    create_logger
 from lib.config import get_config, get_imap_folder, create_imap_connector
 from lib.connector import ImapConnector
 
 if __name__ == '__main__':
-    config = get_config()
+    root_logger = create_logger()
+
+    config = get_config(logger=root_logger)
     if not config:
         exit(1)
 
     sections = config.sections()
     if not sections:
-        print('No IMAP servers configured. Nothing to do.')
+        root_logger.warning('No IMAP servers configured. Nothing to do.')
         exit(0)
 
+    root_logger.info('Testing %s configured IMAP connections...', len(sections))
     for section in sections:
-        connector: ImapConnector = create_imap_connector(config=config, section=section)
+        logger = create_logger(section)
+
+        try:
+            connector: ImapConnector = create_imap_connector(config=config, section=section)
+        except Exception as ex:
+            logger.exception('Invalid configuration. %s', str(ex))
+            continue
 
-        print('[%s] Testing connection...' % section)
+        logger.info('Testing connection...')
         client: IMAPClient | None = None
         try:
             folder = get_imap_folder(config=config, section=section)
@@ -51,63 +60,50 @@
                     select_folder_readonly=True,
                 )
             except Exception as ex:
-                print('[%s] ERROR: Connection failed! %s\n%s' % (
-                    section,
-                    str(ex),
-                    '\n'.join(traceback.format_exception(ex)),
-                ))
+                logger.exception('Connection failed. %s', str(ex))
                 continue
 
-            print('[%s] Connection successful.' % section)
+            logger.info('Connection successful.')
 
             try:
                 capabilities = []
                 for cap in client.capabilities():
                     capabilities.append(cap.decode('utf-8'))
 
-                print('[%s] Capabilities: %s' % (section, ', '.join(sorted(capabilities)),))
+                logger.info('Capabilities: %s', ', '.join(sorted(capabilities)))
             except Exception as ex:
-                print('[%s] ERROR: Can\'t load server capabilities! %s\n%s' % (
-                    section,
-                    str(ex),
-                    '\n'.join(traceback.format_exception(ex)),
-                ))
+                logger.exception('Can\'t load server capabilities. %s', str(ex))
                 continue
 
-            print('[%s] Fetch latest message from "%s".' % (section, folder,))
+            logger.info('Fetch latest message from "%s".', folder)
             message_numbers = client.search()
             if len(message_numbers) < 1:
-                print('[%s] No messages found in "%s".' % (section, folder,))
+                logger.info('No messages found in "%s".', folder)
                 continue
 
             last_message_number = message_numbers[len(message_numbers) - 1]
-            # print('[%s] Fetching message number #%s...' % (section, last_message_number,))
-
             result = client.fetch([last_message_number], ['ENVELOPE'])
             if last_message_number not in result:
-                print('[%s] ERROR: No envelope data found for message nr %s in "%s".' % (
-                    section,
-                    last_message_number,
-                    folder,
-                ))
+                logger.error('No envelope data found for message nr %s in "%s".', last_message_number, folder)
                 continue
 
-            print('[%s] Latest message in "%s":' % (section, folder,))
+            message_info = ['Latest message in "%s":' % folder]
 
             last_message_envelope: Envelope = result[last_message_number][b'ENVELOPE']
-            # pprint(last_message_envelope)
 
             msg_date: datetime | None = get_envelope_date(last_message_envelope)
-            print('-> Date    : %s' % msg_date)
+            message_info.append('-> Date    : %s' % msg_date)
 
             subject: str | None = get_envelope_subject(last_message_envelope)
-            print('-> Subject : %s' % subject)
+            message_info.append('-> Subject : %s' % subject)
 
             from_address: Address | None = get_envelope_from_first(last_message_envelope)
-            print('-> From    : %s' % str(from_address))
+            message_info.append('-> From    : %s' % str(from_address))
 
             sender_address: Address | None = get_envelope_sender_first(last_message_envelope)
-            print('-> Sender  : %s' % str(sender_address))
+            message_info.append('-> Sender  : %s' % str(sender_address))
+
+            logger.info('\n'.join(message_info))
 
         finally:
             # noinspection PyBroadException

src/lib/__init__.py

@@ -14,6 +14,8 @@
 # limitations under the License.
 #
 
+import logging
+import sys
 from datetime import datetime
 from enum import Enum
 
@@ -32,6 +34,32 @@ class EncryptionCertificateCheck(Enum):
     REQUIRED = 'required'
 
 
+__LOGGERS: dict[str, logging.Logger] = {}
+
+
+def create_logger(name: str = 'app', level: int = logging.INFO) -> logging.Logger:
+    if name in __LOGGERS:
+        return __LOGGERS[name]
+
+    logger: logging.Logger = logging.getLogger(name)
+    logger.setLevel(level)
+
+    # noinspection SpellCheckingInspection
+    logger_format = '[%(levelname)s] %(asctime)s | %(message)s' if name == 'app' \
+        else '[%(levelname)s:%(name)s] %(asctime)s | %(message)s'
+    formatter: logging.Formatter = logging.Formatter(
+        fmt=logger_format,
+        datefmt='%Y-%m-%d %H:%M:%S'
+    )
+
+    handler: logging.StreamHandler = logging.StreamHandler(stream=sys.stdout)
+    handler.setFormatter(formatter)
+    logger.addHandler(handler)
+
+    __LOGGERS[name] = logger
+    return logger
+
+
 def get_address_mail(address: Address, charset='utf-8') -> str | None:
     """
     Extracts mail address from an address.
@@ -59,7 +87,7 @@ def get_address_name(address: Address, charset='utf-8') -> str | None:
     :return: mail name or None, if invalid
     """
 
-    if address.name:
+    if not address.name:
         return None
 
     return address.name.decode(charset).strip()

src/lib/callback.py

@@ -15,7 +15,6 @@
 #
 
 import subprocess
-import traceback
 from datetime import datetime
 from os import getcwd
 from threading import Thread
@@ -30,7 +29,8 @@
     get_envelope_sender_first, \
     get_envelope_to_first, \
     get_address_name, \
-    get_address_mail
+    get_address_mail, \
+    create_logger
 
 
 class CallbackHandler:
@@ -115,6 +115,14 @@ def __init__(
         self.__command = command
         self.__environment = {**environment}
         self.__thread = Thread(target=self.__run)
+        self.__logger = create_logger(self.__name)
+
+        # make sure, that environment dict does not contain None values
+        # as it might lead to errors on execution
+        for key, value in self.__environment.items():
+            if value is None:
+                self.__logger.warning('Environment variable "%s" has None value.', key)
+                self.__environment[key] = ''
 
     def start(self):
         """
@@ -136,31 +144,22 @@ def __run(self):
         """
 
         try:
-            print('[%s] Running "%s" from working directory "%s"...' % (
-                self.__name,
-                self.__command,
-                getcwd(),
-            ))
+            self.__logger.info('Running "%s" from working directory "%s"...', self.__command, getcwd())
 
             result: subprocess.CompletedProcess = subprocess.run(
                 self.__command,
                 shell=True,
                 env=self.__environment,
-                cwd=getcwd(),
-                text=True
+                cwd=getcwd()
             )
 
             if result.returncode != 0:
-                print('[%s] ERROR: Callback script "%s" returned non-zero exit code (%s)!' % (
-                    self.__name,
+                self.__logger.warning(
+                    'Callback script "%s" returned non-zero exit code (%s)!',
                     self.__command,
-                    result.returncode,
-                ))
+                    result.returncode
+                )
                 return
 
         except Exception as ex:
-            print('[%s] ERROR: Callback script error! %s\n%s' % (
-                self.__name,
-                str(ex),
-                '\n'.join(traceback.format_exception(ex)),
-            ))
+            self.__logger.exception('Unexpected callback error. %s', str(ex))

src/lib/config.py

@@ -14,6 +14,7 @@
 # limitations under the License.
 #
 
+import logging
 import os
 import sys
 from configparser import ConfigParser
@@ -24,14 +25,14 @@
 from .idle import ImapIdleHandler
 
 
-def get_config() -> ConfigParser | None:
+def get_config(logger: logging.Logger) -> ConfigParser | None:
     if len(sys.argv) < 2:
-        print('ERROR: Please provide a config file as first argument!')
+        logger.error('Please provide a config file as first argument!')
         return None
 
     config_path = sys.argv[1]
     if not os.path.isfile(config_path):
-        print('ERROR: Can\'t find config file at "%s"!' % config_path)
+        logger.error('Can\'t find config file at "%s"!' % config_path)
         return None
 
     config = ConfigParser()
@@ -74,15 +75,20 @@ def create_imap_connector(
         section: str,
         use_uid=False
 ) -> ImapConnector:
+    try:
+        port: int = int(config.get(
+            section, 'port',
+            fallback='143',
+        ).strip())
+    except ValueError:
+        raise Exception('Can\'t read port number "%s".' % config.get(section, 'port'))
+
     return ImapConnector(
         host=config.get(
             section, 'host',
             fallback='localhost',
         ),
-        port=int(config.get(
-            section, 'port',
-            fallback='143',
-        ).strip()),
+        port=port,
         username=config.get(
             section, 'username',
             fallback=None,