🔀 Add a basic logger to the template

Do not use `print()` anymore in the script to print stuff on STDOUT,
use `logger.info()` instead.

If script is run in crontab, it loggs to syslog.

main.py

@@ -12,9 +12,48 @@ This file is part of [`<GIT REPO NAME>`](<GIT REPO URL>)
 """
 
 import argparse
-from os import environ
+import logging
+import logging.handlers
+from os import environ, path
 import sys
-from pprint import pprint as pp
+
+
+logger = logging.getLogger(path.splitext(path.basename(sys.argv[0]))[0])
+
+
+def setup_logging(options):
+    """Configure logging."""
+    root = logging.getLogger("")
+    logger.setLevel(options.debug and logging.DEBUG or logging.INFO)
+    format_debug = "%(levelname)s\t[%(name)s] %(message)s"
+    format_default = "%(message)s"
+
+    if options.debug:
+        # Logging with --debug option
+
+        if not sys.stderr.isatty():
+            # Logging in a file when launched not in a terminal
+
+            facility = logging.handlers.SysLogHandler.LOG_DAEMON
+            handler_syslog = logging.handlers.SysLogHandler(
+                address="/dev/log", facility=facility
+            )
+            handler_syslog.setFormatter(logging.Formatter(format_default))
+            root.addHandler(handler_syslog)
+
+        else:
+            # Logging on terminal standard output
+
+            handler_console = logging.StreamHandler()
+            handler_console.setFormatter(logging.Formatter(format_debug))
+            root.addHandler(handler_console)
+
+    else:
+        # Logging default setings
+
+        handler_console = logging.StreamHandler()
+        handler_console.setFormatter(logging.Formatter(format_default))
+        root.addHandler(handler_console)
 
 
 class CustomFormatter(
@@ -110,15 +149,16 @@ def main():
     2
     """
     pargs = parse_args()
+    setup_logging(pargs)
 
     if pargs.foo:
-        pp(i_am_foo())
+        logger.info(i_am_foo())
 
     elif pargs.bar:
-        pp(i_am_bar(pargs.bar))
+        logger.info(i_am_bar(pargs.bar))
 
     if pargs.debug and pargs:
-        pp(pargs)
+        logger.debug(pargs)
 
 
 if __name__ == "__main__":