Add config init flow from a file in a config directory

amanuensis/__main__.py

@@ -55,15 +55,34 @@ def get_parser(valid_commands):
 	parser = argparse.ArgumentParser(
 		description="Available commands:\n{}\n".format(command_descs),
 		formatter_class=argparse.RawDescriptionHelpFormatter)
+	# The config directory.
+	parser.add_argument("--config-dir",
+		dest="config_dir",
+		default=os.environ.get(configs.ENV_CONFIG_DIR, "./config"),
+		help="The config directory for Amanuensis")
+	# Logging settings.
+	parser.add_argument("--verbose", "-v",
+		action="store_true",
+		dest="verbose",
+		help="Enable verbose console logging")
+	parser.add_argument("--log-file",
+		dest="log_file",
+		default=os.environ.get(configs.ENV_LOG_FILE),
+		help="Enable verbose file logging")
+	parser.add_argument("--log-file-size",
+		dest="log_file_size",
+		default=os.environ.get(configs.ENV_LOG_FILE_SIZE),
+		help="Maximum rolling log file size")
+	parser.add_argument("--log-file-num",
+		dest="log_file_num",
+		default=os.environ.get(configs.ENV_LOG_FILE_NUM),
+		help="Maximum rolling file count")
+	# Lexicon settings.
 	parser.add_argument("-n",
 		metavar="LEXICON",
 		dest="lexicon",
 		help="The name of the lexicon to operate on")
-	parser.add_argument("-v",
-		action="store_true",
-		dest="verbose",
-		help="Enable debug logging")
-	parser.set_defaults(func=repl)
+	parser.set_defaults(func=lambda args: repl(args) if args.lexicon else parser.print_help())
 	subp = parser.add_subparsers(
 		metavar="COMMAND",
 		help="The command to execute")
@@ -90,9 +109,8 @@ def main(argv):
 
 	args = get_parser(commands).parse_args(argv)
 
-	# Configure logging.
-	if args.verbose:
-		configs.log_verbose()
+	# With the arguments parsed, initialize the configs.
+	configs.init(args)
 
 	# Execute command.
 	args.func(args)

amanuensis/cli.py

@@ -2,8 +2,24 @@
 from argparse import ArgumentParser as AP
 from functools import wraps
 
+#
+# The cli module must not import other parts of the application at the module
+# level. This is because most other modules depend on the config module. The
+# config module may depend on __main__'s commandline parsing to locate config
+# files, and __main__'s commandline parsing requires importing (but not
+# executing) the functions in the cli module. Thus, cli functions must only
+# import the config module inside the various command methods, which are only
+# run after commandline parsing has already occurred.
+#
 
+#
+# These function wrappers are used to make the command_* methods accept an
+# ArgumentParser as a parameter, which it then configures with the given
+# argument and returns. This way, we can configure each command's subparser
+# in this module without having to write a separate function to configure it.
+#
 def add_argument(*args, **kwargs):
+	"""Passes the given args and kwargs to subparser.add_argument"""
 	def argument_adder(command):
 		@wraps(command)
 		def augmented_command(cmd_args):
@@ -15,6 +31,7 @@ def add_argument(*args, **kwargs):
 	return argument_adder
 
 def no_argument(command):
+	"""Noops for subparsers"""
 	@wraps(command)
 	def augmented_command(cmd_args):
 		if type(cmd_args) is not AP:
@@ -22,7 +39,9 @@ def no_argument(command):
 	return augmented_command
 
 @add_argument("--foo", action="store_true")
-def command_a(args):
-	"""a docstring"""
-	print(args.foo)
+def command_dump(args):
+	"""Dumps the global config or the config for the given lexicon"""
+	import json
+	import configs
+	print(json.dumps(configs.GLOBAL_CONFIG, indent=2))
 

amanuensis/configs.py

@@ -1,19 +1,93 @@
+# Standard library imports
+from collections import OrderedDict as odict
+import copy
+import json
 import logging
+import logging.config
+import os
 
-logger = logging.getLogger("amanuensis")
-handler = logging.StreamHandler()
-logger.addHandler(handler)
+# Module imports
+from errors import MissingConfigError, MalformedConfigError
 
-def log_normal():
-	logger.setLevel(logging.INFO)
-	handler.setLevel(logging.INFO)
-	formatter = logging.Formatter('[{levelname}] {message}', style="{")
-	handler.setFormatter(formatter)
 
-def log_verbose():
-	logger.setLevel(logging.DEBUG)
-	handler.setLevel(logging.DEBUG)
-	formatter = logging.Formatter('[{asctime}] [{levelname}:{filename}:{lineno}] {message}', style="{")
-	handler.setFormatter(formatter)
+# Environment variable name constants
+ENV_CONFIG_DIR =    "AMANUENSIS_CONFIG_DIR"
+ENV_LOG_FILE =      "AMANUENSIS_LOG_FILE"
+ENV_LOG_FILE_SIZE = "AMANUENSIS_LOG_FILE_SIZE"
+ENV_LOG_FILE_NUM =  "AMANUENSIS_LOG_FILE_NUM"
+
+# Functions to be used for moving configs on and off of disk.
+def read(path):
+	with open(path, 'r') as config_file:
+		return json.load(config_file, object_pairs_hook=odict)
+
+def write(config, path):
+	with open(path, 'w') as dest_file:
+		json.dump(config, dest_file, allow_nan=False, indent='\t')
+
+#
+# The config directory can be set by cli input, so the config infrastructure
+# needs to wait for initialization before it can load any configs.
+#
+CONFIG_DIR = None
+GLOBAL_CONFIG = None
+
+def init(args):
+	"""
+	Initializes the config infrastructure to read configs from the
+	directory given by args.config_dir. Initializes logging.
+	"""
+	# Check that config dir exists
+	if not os.path.isdir(args.config_dir):
+		raise MissingConfigError("Config directory not found: {}".format(args.config_dir))
+	# Check that global config file exists
+	global_config_path = os.path.join(args.config_dir, "config.json")
+	if not os.path.isfile(global_config_path):
+		raise MissingConfigError("Config directory missing global config file: {}".format(args.config_dir))
+	# Check that global config file has logging settings
+	global_config_file = read(global_config_path)
+	if 'logging' not in global_config_file.keys():
+		raise MalformedConfigError("No 'logging' section in global config")
+	# Check that the global config file has a lexicon data directory
+	if 'lexicon_data' not in global_config_file.keys():
+		raise MalformedConfigError("No 'lexicon_data' setting in global config")
+	# Configs verified, use them for initialization
+	global CONFIG_DIR, GLOBAL_CONFIG
+	CONFIG_DIR = args.config_dir
+	GLOBAL_CONFIG = global_config_file
+	# Initialize logging
+	init_logging(args)
+
+def init_logging(args):
+	"""
+	Initializes logging by using the logging section of the global config
+	file.
+	"""
+	# Get the logging config section
+	cfg = copy.deepcopy(GLOBAL_CONFIG['logging'])
+	# Apply any commandline settings to what was defined in the config file
+	handlers = cfg['loggers']['amanuensis']['handlers']
+	if args.verbose:
+		if 'cli-basic' in handlers:
+			handlers.remove('cli_basic')
+		handlers.append('cli_verbose')
+	if args.log_file:
+		cfg['handlers']['file']['filename'] = args.log_file
+		handlers.append("file")
+	# Load the config
+	try:
+		logging.config.dictConfig(cfg)
+	except:
+		raise MalformedConfigError("Failed to load logging config")
+
+def logger():
+	"""Returns the main logger"""
+	return logging.getLogger("amanuensis")
+
+# Global config values, which shouldn't be changing during runtime, are
+# accessed through config.get()
+
+def get(key):
+	"""Gets the given config value from the global config"""
+	return GLOBAL_CONFIG[key]
 
-log_normal()

amanuensis/errors.py

@@ -0,0 +1,9 @@
+class AmanuensisError(Exception):
+	"""Base class for exceptions in amanuensis"""
+	pass
+
+class MissingConfigError(AmanuensisError):
+	pass
+
+class MalformedConfigError(AmanuensisError):
+	pass