X-Git-Url: https://wannabe.guru.org/gitweb/?a=blobdiff_plain;f=config.py;h=ea5f68a296b66ea8946a61e6f85fe1891a0b33a8;hb=eb9e6df32ed696158bf34dba6464277b648f5c74;hp=b3580ceed0663bdb34b946d465ea3c2fca3b05f6;hpb=e024f55a3d5b652d0745b6978a28c83f62711e59;p=python_utils.git diff --git a/config.py b/config.py index b3580ce..ea5f68a 100644 --- a/config.py +++ b/config.py @@ -1,7 +1,9 @@ #!/usr/bin/env python3 -"""Global configuration driven by commandline arguments (even across -different modules). Usage: +"""Global configuration driven by commandline arguments, environment variables +and saved configuration files. This works across several modules. + +Usage: module.py: ---------- @@ -36,7 +38,8 @@ different modules). Usage: config.parse() # Very important, this must be invoked! If you set this up and remember to invoke config.parse(), all commandline - arguments will play nicely together: + arguments will play nicely together. This is done automatically for you + if you're using the bootstrap module's initialize wrapper. % main.py -h usage: main.py [-h] @@ -73,10 +76,6 @@ from typing import Any, Dict, List, Optional # This module is commonly used by others in here and should avoid # taking any unnecessary dependencies back on them. -# Note: at this point in time, logging hasn't been configured and -# anything we log will come out the root logger. -logger = logging.getLogger(__name__) - # Defer logging messages until later when logging has been initialized. saved_messages: List[str] = [] @@ -84,23 +83,26 @@ saved_messages: List[str] = [] program_name = os.path.basename(sys.argv[0]) original_argv = [arg for arg in sys.argv] + # A global parser that we will collect arguments into. args = argparse.ArgumentParser( description=None, formatter_class=argparse.ArgumentDefaultsHelpFormatter, fromfile_prefix_chars="@", - epilog=f'-----------------------------------------------------------------------------\n{program_name} uses config.py ({__file__}) for global, cross-module configuration setup and parsing.\n-----------------------------------------------------------------------------' + epilog=f'{program_name} uses config.py ({__file__}) for global, cross-module configuration setup and parsing.' ) # Keep track of if we've been called and prevent being called more # than once. config_parse_called = False + # A global configuration dictionary that will contain parsed arguments. # It is also this variable that modules use to access parsed arguments. # This is the data that is most interesting to our callers; it will hold # the configuration result. -config: Dict[str, Any] = {} +config = {} +# It would be really nice if this shit worked from interactive python def add_commandline_args(title: str, description: str = ""): @@ -116,20 +118,20 @@ group.add_argument( '--config_loadfile', metavar='FILENAME', default=None, - help='Config file from which to read args in lieu or in addition to commandline.', + help='Config file (populated via --config_savefile) from which to read args in lieu or in addition to commandline.', ) group.add_argument( '--config_dump', default=False, action='store_true', - help='Display the global configuration on STDERR at program startup.', + help='Display the global configuration (possibly derived from multiple sources) on STDERR at program startup.', ) group.add_argument( '--config_savefile', type=str, metavar='FILENAME', default=None, - help='Populate config file compatible --config_loadfile to save config for later use.', + help='Populate config file compatible with --config_loadfile to save global config for later use.', ) @@ -142,10 +144,12 @@ def is_flag_already_in_argv(var: str): def parse(entry_module: Optional[str]) -> Dict[str, Any]: - """Main program should call this early in main()""" + """Main program should call this early in main(). Note that the + bootstrap.initialize wrapper takes care of this automatically. + + """ global config_parse_called if config_parse_called: - logger.warning('config.parse has already been called; ignoring spurious invocation') return config global saved_messages @@ -166,8 +170,8 @@ def parse(entry_module: Optional[str]) -> Dict[str, Any]: reordered_action_groups.insert(0, group) args._action_groups = reordered_action_groups - # Examine the environment variables that match known flags. For a - # flag called --example_flag the corresponding environment + # Examine the environment for variables that match known flags. + # For a flag called --example_flag the corresponding environment # variable would be called EXAMPLE_FLAG. usage_message = args.format_usage() optional = False @@ -224,18 +228,17 @@ def parse(entry_module: Optional[str]) -> Dict[str, Any]: if loadfile is not None: if saw_other_args: - print( - 'WARNING: ignoring some commandline arguments; only args in --config_loadfile be parsed.', - file=sys.stderr - ) + msg = f'Augmenting commandline arguments with those from {loadfile}.' + print(msg, file=sys.stderr) + saved_messages.append(msg) if not os.path.exists(loadfile): - print(f'--config_loadfile argument must be a file, {loadfile} not found.', + print(f'ERROR: --config_loadfile argument must be a file, {loadfile} not found.', file=sys.stderr) sys.exit(-1) with open(loadfile, 'r') as rf: newargs = rf.readlines() newargs = [arg.strip('\n') for arg in newargs if 'config_savefile' not in arg] - sys.argv = sys.argv[:1] + newargs + sys.argv += newargs # Parse (possibly augmented, possibly completely overwritten) # commandline args with argparse normally and populate config. @@ -274,6 +277,7 @@ def dump_config(): """Print the current config to stdout.""" print("Global Configuration:", file=sys.stderr) pprint.pprint(config, stream=sys.stderr) + print() def late_logging():