Fixed eclipse-volttron#229 adding logic to detect the output to file.

src/volttron/server/__main__.py

@@ -40,25 +40,31 @@
 should happen is setting up of logging and verbosity for the server.  After
 that we hand off to the run_server method, which will start the server process.
 """
+import logging
 import logging.config
 import os
 from pathlib import Path
 import sys
 
 import yaml
 
-from volttron.server.logs import get_default_logging_config
+from volttron.server.logs import get_default_logging_config, log_to_file
 
+file_to_log_to: str | None = None
 total_count: int = 0
 logging_config: Path | str | None = None
 
-for arg in sys.argv:
+arg_iter = iter(sys.argv)
+for arg in arg_iter:
     vcount = 0
 
     if arg.startswith("-v"):
         vcount = arg.count("v")
     elif arg == "--verbose":
         vcount = 1
+    elif arg == "--log" or arg == "-l":
+        file_to_log_to = next(arg_iter)
+
     elif arg == "--log-config" or arg == "-L":
         # Find the index of the log configuration so we can replace the
         # file with absolute path.
@@ -78,20 +84,21 @@
 
     total_count += vcount
 
-logging.config.dictConfig(get_default_logging_config(level=total_count))
-
+# If the user has specified a logging configuration then allow them full access to all the
+# responsibility of logging.
 if logging_config:
     with open(logging_config, 'rt') as f:
         cfg = yaml.safe_load(f.read())
 
     logging.config.dictConfig(cfg)
 
-# from volttron.utils.logs import enable_trace, setup_logging
-
-# setup_logging(total_count)
+# The user wants to output all to a file so we can do that for them.
+if file_to_log_to:
+    log_to_file(file_to_log_to, total_count, handler_class=logging.handlers.WatchedFileHandler)
 
-# if total_count <= logging.DEBUG:
-#     enable_trace()
+# Normal here just use the default stream handler setup.
+else:
+    logging.config.dictConfig(get_default_logging_config(level=total_count))
 
 from volttron.server.run_server import _main