cli: expand user's home directory for logging

* Allow to specify a log path relative to the user's home directory in
  the configuration file.

Bug: T244840
Change-Id: I229084cad7fd1186f631d4cb41d95f4f9260aa6b

cumin/cli.py

@@ -451,7 +451,7 @@ def main(argv=None):
         user = get_running_user()
         config = cumin.Config(args.config)
         validate_config(config)
-        setup_logging(config['log_file'], debug=args.debug, trace=args.trace)
+        setup_logging(os.path.expanduser(config['log_file']), debug=args.debug, trace=args.trace)
     except cumin.CuminError as e:
         stderr(e)
         return 2

doc/examples/config.yaml

@@ -3,7 +3,7 @@
 # By default Cumin load the configuration from /etc/cumin/config.yaml, but it can be overriden by command line argument
 #
 transport: clustershell  # Default transport to use, can be overriden by command line argument
-log_file: logs/cumin.log  # Absolute or relative path for the log file
+log_file: ~/.cumin/cumin.log  # Absolute or relative path for the log file, expands ~ into the user's home directory
 # If set, use this backend to parse the query first and only if it fails, fallback to parse it with the general
 # multi-query grammar [optional]
 default_backend: direct