parse_challonge_credentials.py

#!/usr/bin/env python3

"""Tool for parsing Challonge credentials from a config file.

The Challonge API key is something you want to keep secret. I set up this tool
so you can easily parse your Challonge info from a config file that can be
ignored from your git repo instead of hardcoding it into your code.

Example:

  python parse_challonge_config.py my_challonge.ini
    => { user: 'blah', api_key: 'not telling' }
"""


import configparser
import sys

import defaults


# Section in the config file with challonge credential info.
_CHALLONGE_CONFIG_CREDENTIAL_SECTION = "Challonge Credentials"
_CHALLONGE_CONFIG_USER_OPTION = "user"
_CHALLONGE_CONFIG_API_KEY_OPTION = "api_key"


def parse_challonge_credentials_from_config(config_filename):
    """Parses Challonge credentials from a config file.

    Args:
      config_filename: The filename of the config file to parse.

    Raises:
      ConfigParser.NoSectionError:
        If the file doesn't exist or the Challonge Credentials section doesn't
        exist in the config file.

      ConfigParser.NoOptionError:
        If the user or api_key options don't exist in the config file.

    Returns:
      A dictionary with {"user", "api_key"} keys parsed from the config file.
    """
    config_parser = configparser.RawConfigParser()
    config_parser.read(config_filename)

    user = config_parser.get(
        _CHALLONGE_CONFIG_CREDENTIAL_SECTION, _CHALLONGE_CONFIG_USER_OPTION
    )
    api_key = config_parser.get(
        _CHALLONGE_CONFIG_CREDENTIAL_SECTION, _CHALLONGE_CONFIG_API_KEY_OPTION
    )

    return {"user": user, "api_key": api_key}


def safe_parse_challonge_credentials_from_config(config_filename):
    """Parses Challonge credentials from a config file with error handling.

    Config parsing errors will be caught and logged to stderr.

    Args:
      config_filenae: The filename of the config file to parse.

    Returns:
      A dictionary with {"user", "api_key"} keys parsed from the config file,
      or None if the credentials could not be parsed.
    """
    try:
        return parse_challonge_credentials_from_config(config_filename)
    except configparser.Error as err:
        sys.stderr.write(
            "Failed to read credentials from {0}: {1}.\n".format(config_filename, err)
        )
        sys.stderr.write(
            "Check {0} for instructions on how to setup your config.\n".format(
                defaults.DEFAULT_CONFIG_FILENAME
            )
        )
        return None


if __name__ == "__main__":
    if len(sys.argv) > 2:
        sys.stderr.write("Usage: {0} [<credentials_file>]\n".format(sys.argv[0]))
        sys.exit(1)

    if len(sys.argv) == 2:
        config_filename = sys.argv[1]
    else:
        config_filename = defaults.DEFAULT_CONFIG_FILENAME

    credentials = safe_parse_challonge_credentials_from_config(config_filename)
    if not credentials:
        sys.exit(1)
    else:
        print(credentials)