Since this thing is on the innerwebs I suppose it should have a

[python_utils.git] / config.py

diff --git a/config.py b/config.py
index ea5f68a296b66ea8946a61e6f85fe1891a0b33a8..bea701837c520ca86d584f9b48cead98ab06e838 100644 (file)
--- a/config.py
+++ b/config.py
@@ -1,5 +1,7 @@
 #!/usr/bin/env python3
 
 #!/usr/bin/env python3
 

+# © Copyright 2021-2022, Scott Gasch
+

 """Global configuration driven by commandline arguments, environment variables
 and saved configuration files.  This works across several modules.
 
 """Global configuration driven by commandline arguments, environment variables
 and saved configuration files.  This works across several modules.
 


@@ -77,37 +79,52 @@ from typing import Any, Dict, List, Optional
 # taking any unnecessary dependencies back on them.
 
 # Defer logging messages until later when logging has been initialized.
 # taking any unnecessary dependencies back on them.
 
 # Defer logging messages until later when logging has been initialized.

-saved_messages: List[str] = []
+SAVED_MESSAGES: List[str] = []

 
 # Make a copy of the original program arguments.
 
 # Make a copy of the original program arguments.

-program_name = os.path.basename(sys.argv[0])
-original_argv = [arg for arg in sys.argv]
+PROGRAM_NAME: str = os.path.basename(sys.argv[0])
+ORIG_ARGV: List[str] = sys.argv.copy()
+
+
+class OptionalRawFormatter(argparse.HelpFormatter):
+    """This formatter has the same bahavior as the normal argparse text
+    formatter except when the help text of an argument begins with
+    "RAW|".  In that case, the line breaks are preserved and the text
+    is not wrapped.
+
+    """
+
+    def _split_lines(self, text, width):
+        if text.startswith('RAW|'):
+            return text[4:].splitlines()
+        return argparse.HelpFormatter._split_lines(self, text, width)

 
 
 # A global parser that we will collect arguments into.
 
 
 # A global parser that we will collect arguments into.

-args = argparse.ArgumentParser(
+ARGS = argparse.ArgumentParser(

     description=None,
     description=None,

-    formatter_class=argparse.ArgumentDefaultsHelpFormatter,
+    formatter_class=OptionalRawFormatter,

     fromfile_prefix_chars="@",
     fromfile_prefix_chars="@",

-    epilog=f'{program_name} uses config.py ({__file__}) for global, cross-module configuration setup and parsing.'
+    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.
 )
 
 # Keep track of if we've been called and prevent being called more
 # than once.

-config_parse_called = False
+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.
 
 
 # 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 = {}
+config: Dict[str, Any] = {}
+

 # It would be really nice if this shit worked from interactive python
 
 
 def add_commandline_args(title: str, description: str = ""):
     """Create a new context for arguments and return a handle."""
 # It would be really nice if this shit worked from interactive python
 
 
 def add_commandline_args(title: str, description: str = ""):
     """Create a new context for arguments and return a handle."""

-    return args.add_argument_group(title, description)
+    return ARGS.add_argument_group(title, description)

 
 
 group = add_commandline_args(
 
 
 group = add_commandline_args(


@@ -133,6 +150,20 @@ group.add_argument(
     default=None,
     help='Populate config file compatible with --config_loadfile to save global config for later use.',
 )
     default=None,
     help='Populate config file compatible with --config_loadfile to save global config for later use.',
 )

+group.add_argument(
+    '--config_rejects_unrecognized_arguments',
+    default=False,
+    action='store_true',
+    help=(
+        'If present, config will raise an exception if it doesn\'t recognize an argument.  The '
+        + 'default behavior is to ignore this so as to allow interoperability with programs that '
+        + 'want to use their own argparse calls to parse their own, separate commandline args.'
+    ),
+)
+
+
+def overwrite_argparse_epilog(msg: str) -> None:
+    ARGS.epilog = msg

 
 
 def is_flag_already_in_argv(var: str):
 
 
 def is_flag_already_in_argv(var: str):


@@ -143,37 +174,20 @@ def is_flag_already_in_argv(var: str):
     return False
 
 
     return False
 
 

-def parse(entry_module: Optional[str]) -> Dict[str, Any]:
-    """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:
-        return config
-
-    global saved_messages
-
-    # If we're about to do the usage message dump, put the main module's
-    # argument group last in the list (if possible) so that when the user
-    # passes -h or --help, it will be visible on the screen w/o scrolling.
+def reorder_arg_action_groups_before_help(entry_module: Optional[str]):

     reordered_action_groups = []
     reordered_action_groups = []

-    global prog
-    for arg in sys.argv:
-        if arg == '--help' or arg == '-h':
-            for group in args._action_groups:
-                if entry_module is not None and entry_module in group.title:
-                    reordered_action_groups.append(group)
-                elif program_name in group.title:
-                    reordered_action_groups.append(group)
-                else:
-                    reordered_action_groups.insert(0, group)
-            args._action_groups = reordered_action_groups
+    for grp in ARGS._action_groups:
+        if entry_module is not None and entry_module in grp.title:  # type: ignore
+            reordered_action_groups.append(grp)
+        elif PROGRAM_NAME in group.title:  # type: ignore
+            reordered_action_groups.append(grp)
+        else:
+            reordered_action_groups.insert(0, grp)
+    return reordered_action_groups

 
 

-    # 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()
+
+def augment_sys_argv_from_environment_variables():
+    usage_message = ARGS.format_usage()

     optional = False
     var = ''
     for x in usage_message.split():
     optional = False
     var = ''
     for x in usage_message.split():


@@ -196,10 +210,9 @@ def parse(entry_module: Optional[str]) -> Dict[str, Any]:
                 if env in os.environ:
                     if not is_flag_already_in_argv(var):
                         value = os.environ[env]
                 if env in os.environ:
                     if not is_flag_already_in_argv(var):
                         value = os.environ[env]

-                        saved_messages.append(
-                            f'Initialized from environment: {var} = {value}'
-                        )
+                        SAVED_MESSAGES.append(f'Initialized from environment: {var} = {value}')

                         from string_utils import to_bool
                         from string_utils import to_bool

+

                         if len(chunks) == 1 and to_bool(value):
                             sys.argv.append(var)
                         elif len(chunks) > 1:
                         if len(chunks) == 1 and to_bool(value):
                             sys.argv.append(var)
                         elif len(chunks) > 1:


@@ -207,10 +220,9 @@ def parse(entry_module: Optional[str]) -> Dict[str, Any]:
                             sys.argv.append(value)
                 var = ''
                 env = ''
                             sys.argv.append(value)
                 var = ''
                 env = ''

-        else:
-            next

 
 

-    # Look for loadfile and read/parse it if present.
+
+def augment_sys_argv_from_loadfile():

     loadfile = None
     saw_other_args = False
     grab_next_arg = False
     loadfile = None
     saw_other_args = False
     grab_next_arg = False


@@ -227,50 +239,86 @@ def parse(entry_module: Optional[str]) -> Dict[str, Any]:
             saw_other_args = True
 
     if loadfile is not None:
             saw_other_args = True
 
     if loadfile is not None:

+        if not os.path.exists(loadfile):
+            raise Exception(
+                f'ERROR: --config_loadfile argument must be a file, {loadfile} not found.'
+            )

         if saw_other_args:
             msg = f'Augmenting commandline arguments with those from {loadfile}.'
         if saw_other_args:
             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'ERROR: --config_loadfile argument must be a file, {loadfile} not found.',
-                  file=sys.stderr)
-            sys.exit(-1)
+        else:
+            msg = f'Reading commandline arguments from {loadfile}.'
+        print(msg, file=sys.stderr)
+        SAVED_MESSAGES.append(msg)
+

         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 += newargs
 
         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 += newargs
 

+
+def parse(entry_module: Optional[str]) -> Dict[str, Any]:
+    """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:
+        return config
+
+    # If we're about to do the usage message dump, put the main
+    # module's argument group last in the list (if possible) so that
+    # when the user passes -h or --help, it will be visible on the
+    # screen w/o scrolling.
+    for arg in sys.argv:
+        if arg in ('--help', '-h'):
+            if entry_module is not None:
+                entry_module = os.path.basename(entry_module)
+            ARGS._action_groups = reorder_arg_action_groups_before_help(entry_module)
+
+    # Examine the environment for variables that match known flags.
+    # For a flag called --example_flag the corresponding environment
+    # variable would be called EXAMPLE_FLAG.  If found, hackily add
+    # these into sys.argv to be parsed.
+    augment_sys_argv_from_environment_variables()
+
+    # Look for loadfile and read/parse it if present.  This also
+    # works by jamming these values onto sys.argv.
+    augment_sys_argv_from_loadfile()
+

     # Parse (possibly augmented, possibly completely overwritten)
     # commandline args with argparse normally and populate config.
     # Parse (possibly augmented, possibly completely overwritten)
     # commandline args with argparse normally and populate config.

-    known, unknown = args.parse_known_args()
+    known, unknown = ARGS.parse_known_args()

     config.update(vars(known))
 
     # Reconstruct the argv with unrecognized flags for the benefit of
     # future argument parsers.  For example, unittest_main in python
     # has some of its own flags.  If we didn't recognize it, maybe
     # someone else will.
     config.update(vars(known))
 
     # Reconstruct the argv with unrecognized flags for the benefit of
     # future argument parsers.  For example, unittest_main in python
     # has some of its own flags.  If we didn't recognize it, maybe
     # someone else will.

+    if len(unknown) > 0:
+        if config['config_rejects_unrecognized_arguments']:
+            raise Exception(
+                f'Encountered unrecognized config argument(s) {unknown} with --config_rejects_unrecognized_arguments enabled; halting.'
+            )
+        SAVED_MESSAGES.append(f'Config encountered unrecognized commandline arguments: {unknown}')

     sys.argv = sys.argv[:1] + unknown
 
     # Check for savefile and populate it if requested.
     savefile = config['config_savefile']
     if savefile and len(savefile) > 0:
         with open(savefile, 'w') as wf:
     sys.argv = sys.argv[:1] + unknown
 
     # Check for savefile and populate it if requested.
     savefile = config['config_savefile']
     if savefile and len(savefile) > 0:
         with open(savefile, 'w') as wf:

-            wf.write(
-                "\n".join(original_argv[1:])
-            )
+            wf.write("\n".join(ORIG_ARGV[1:]))

 
     # Also dump the config on stderr if requested.
     if config['config_dump']:
         dump_config()
 
 
     # Also dump the config on stderr if requested.
     if config['config_dump']:
         dump_config()
 

-    config_parse_called = True
+    CONFIG_PARSE_CALLED = True

     return config
 
 
 def has_been_parsed() -> bool:
     """Has the global config been parsed yet?"""
     return config
 
 
 def has_been_parsed() -> bool:
     """Has the global config been parsed yet?"""

-    global config_parse_called
-    return config_parse_called
+    return CONFIG_PARSE_CALLED

 
 
 def dump_config():
 
 
 def dump_config():


@@ -283,6 +331,6 @@ def dump_config():
 def late_logging():
     """Log messages saved earlier now that logging has been initialized."""
     logger = logging.getLogger(__name__)
 def late_logging():
     """Log messages saved earlier now that logging has been initialized."""
     logger = logging.getLogger(__name__)

-    global saved_messages
-    for _ in saved_messages:
+    logger.debug('Original commandline was: %s', ORIG_ARGV)
+    for _ in SAVED_MESSAGES:

         logger.debug(_)
         logger.debug(_)