Added support to rotate the pgadmin log file on the basis of Size and Age. Fixes #6395

docs/en_US/release_notes_5_4.rst

@@ -11,6 +11,7 @@ New features
 
 | `Issue #2341 <https://redmine.postgresql.org/issues/2341>`_ -  Added support to launch PSQL for the connected database server.
 | `Issue #4064 <https://redmine.postgresql.org/issues/4064>`_ -  Added window maximize/restore functionality for properties dialog.
+| `Issue #6395 <https://redmine.postgresql.org/issues/6395>`_ -  Added support to rotate the pgadmin log file on the basis of Size and Age.
 
 Housekeeping
 ************

web/config.py

@@ -286,6 +286,13 @@ if SERVER_MODE and not IS_WIN:
 else:
     LOG_FILE = os.path.join(DATA_DIR, 'pgadmin4.log')
 
+# Log rotation setting
+# Log file will be rotated considering values for LOG_ROTATION_SIZE
+# & LOG_ROTATION_AGE. Rotated file will be named in format
+# - LOG_FILE.Y-m-d_H-M-S
+LOG_ROTATION_SIZE = 10  # In MBs
+LOG_ROTATION_AGE = 1440  # In minutes
+LOG_ROTATION_MAX_LOG_FILES = 90  # Maximum number of backups to retain
 ##########################################################################
 # Server Connection Driver Settings
 ##########################################################################

web/pgadmin/__init__.py

@@ -262,7 +262,13 @@ def create_app(app_name=None):
         create_app_data_directory(config)
 
         # File logging
-        fh = logging.FileHandler(config.LOG_FILE, encoding='utf-8')
+        from pgadmin.utils.enhanced_log_rotation import \
+            EnhancedRotatingFileHandler
+        fh = EnhancedRotatingFileHandler(config.LOG_FILE,
+                                         config.LOG_ROTATION_SIZE,
+                                         config.LOG_ROTATION_AGE,
+                                         config.LOG_ROTATION_MAX_LOG_FILES)
+
         fh.setLevel(config.FILE_LOG_LEVEL)
         fh.setFormatter(logging.Formatter(config.FILE_LOG_FORMAT))
         app.logger.addHandler(fh)

web/pgadmin/utils/enhanced_log_rotation.py

@@ -0,0 +1,59 @@
+##########################################################################
+#
+# pgAdmin 4 - PostgreSQL Tools
+#
+# Copyright (C) 2013 - 2021, The pgAdmin Development Team
+# This software is released under the PostgreSQL Licence
+#
+##########################################################################
+
+import re
+import logging.handlers as handlers
+
+
+class EnhancedRotatingFileHandler(handlers.TimedRotatingFileHandler,
+                                  handlers.RotatingFileHandler):
+    """
+    Handler for logging to a set of files, which switches from one file
+    to the next when the current file reaches a certain size, or at certain
+    timed intervals
+    @filename - log file name
+    @max_bytes - file size in bytes to rotate  file
+    @interval - Duration to rotate file
+    @backup_count - Maximum number of files to retain
+    @encoding - file encoding
+    @when -  'when' events supported:
+            # S - Seconds
+            # M - Minutes
+            # H - Hours
+            # D - Days
+            # midnight - roll over at midnight
+            # W{0-6} - roll over on a certain day; 0 - Monday
+    Here we are defaulting rotation with minutes interval
+    """
+    def __init__(self, filename, max_bytes=1, interval=60, backup_count=0,
+                 encoding=None, when='M'):
+        max_bytes = max_bytes * 1024 * 1024
+        handlers.TimedRotatingFileHandler.__init__(self, filename=filename,
+                                                   when=when,
+                                                   interval=interval,
+                                                   backupCount=backup_count,
+                                                   encoding=encoding)
+
+        handlers.RotatingFileHandler.__init__(self, filename=filename,
+                                              mode='a',
+                                              maxBytes=max_bytes,
+                                              backupCount=backup_count,
+                                              encoding=encoding)
+
+    # Time & Size combined rollover
+    def shouldRollover(self, record):
+        return handlers.TimedRotatingFileHandler.shouldRollover(self, record) \
+            or handlers.RotatingFileHandler.shouldRollover(self, record)
+
+    # Roll overs current file
+    def doRollover(self):
+        self.suffix = "%Y-%m-%d_%H-%M-%S"
+        self.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}-\d{2}-\d{2}(\.\w+)?$"
+        self.extMatch = re.compile(self.extMatch, re.ASCII)
+        handlers.TimedRotatingFileHandler.doRollover(self)