examples for log file rotation

logging.md

@@ -20,6 +20,8 @@ A logging configuration file can be specified in the `config` configuration
 option in the `logging` section. The file format is explained in the
 [Python Logging Module](https://docs.python.org/3/library/logging.config.html#configuration-file-format).
 
+## Logging to a file
+
 An example configuration to write the log output to the file `/var/log/radicale/log`:
 ```ini
 [loggers]
@@ -48,3 +50,31 @@ format = %(asctime)s - [%(thread)x] %(levelname)s: %(message)s
 
 You can specify multiple **logger**, **handler** and **formatter** if you want
 to have multiple simultaneous log outputs.
+
+### Timed rotation of disk log files
+
+An example **handler** configuration to write the log output to the file `/var/log/radicale/log` and rotate it .
+Replace the section `handle_file` from the file logging example:
+```ini
+[handler_file]
+class = handlers.TimedRotatingFileHandler
+# Specify the output file and parameter for rotation here.
+# See https://docs.python.org/3/library/logging.handlers.html#logging.handlers.TimedRotatingFileHandler
+# Example: rollover at midnight and keep 7 files (means one week)
+args = ('/var/log/radicale/log', when='midnight', interval=1, backupCount=7)
+formatter = full
+```
+
+### Rotation of disk log files based on size
+
+An example **handler** configuration to write the log output to the file `/var/log/radicale/log` and rotate it .
+Replace the section `handle_file` from the file logging example:
+```ini
+[handler_file]
+class = handlers.RotatingFileHandler
+# Specify the output file and parameter for rotation here.
+# See https://docs.python.org/3/library/logging.handlers.html#logging.handlers.RotatingFileHandler
+# Example: rollover at 100000 kB and keep 10 files (means 1 MB)
+args = ('/var/log/radicale/log', 'a', 100000, 10)
+formatter = full
+```