Simple web_app skeleton with arg/conf parsing

web_app.py

#!/usr/bin/env python3
"""
web_app.py
Author: wamsachel
Date: today

web_app is a simple bottle-drive web app which examines how to better handle internet vitriol,
rather than waiting for lawmakers to do so

Usage: $python3 web_app.py
"""

import argparse
from src.bottle import (abort, error, get, post, redirect, request, route, run, template, view, static_file)
import configparser

CONFIGURATION_FILE = './web_app.conf'
CONFIGURATION_SECTION = 'OPTIONS'
APP_DESCRIPTION = '''web_app is a simple bottle-drive web app which examines how to better handle internet vitriol,
rather than waiting for lawmakers to do so
'''


def start_bottle_server(**kwargs):
    """kicks off a bottle web server"""
    if 'address' in kwargs:
        srv_address = kwargs['address']
    else:
        raise Exception('[!] Missing argument: address')
    if 'port' in kwargs:
        srv_port = kwargs['port']
    else:
        raise Exception('[!] Missing argument: port')
    if 'debug' in kwargs:
        srv_debug = kwargs['debug']
    else:
        srv_debug = False

    try:
        run(host=srv_address, port=srv_port, debug=srv_debug, reloader=srv_debug)
    except Exception as e:
        raise e


def read_configuration_file(conf_file, conf_section):
    """ handles configuration file reading, returns dict """
    ret_conf = {}
    config = configparser.ConfigParser()
    try:
        config.read(conf_file)
        if conf_section not in config:
            raise Exception('Invalid configuration file')
    except Exception as e:
        print (repr(e))
    else:
        ret_conf.update(config[conf_section])
    return ret_conf


def read_args():
    """ handles cli arg reading returns dict """
    ret_args = {}
    arg_parser = argparse.ArgumentParser(description=APP_DESCRIPTION)
    arg_parser.add_argument('-a', '--address', required=False, help='Host name for server to run on (e.g 127.0.0.1 or 0.0.0.0)')
    arg_parser.add_argument('-p', '--port', required=False, help='Port for web server to listen on')
    arg_parser.add_argument('-d', '--debug', required=False, action='store_true', help='Run server with debugging options turned on')
    try:
        args = arg_parser.parse_args()
    except Exception as e:
        print(repr(e))
    else:
        if args.address is not None:
            ret_args['address'] = args.address
        if args.port is not None:
            ret_args['port'] = args.port
        if args.debug is not None:
            ret_args['debug'] = args.debug
    return ret_args

if __name__ == '__main__':
    # Read in configuration settings, save into opts_dict
    opts_dict = {}

    conf_opts = read_configuration_file(CONFIGURATION_FILE, CONFIGURATION_SECTION)
    opts_dict.update(conf_opts)

    arg_opts = read_args()
    opts_dict.update(arg_opts)

    for opt in opts_dict:
        print('{}:{}'.format(opt, opts_dict[opt]))

    try:
        start_bottle_server(**opts_dict)
    except Exception as e:
        print(repr(e))
        print('[!] Dirty exit.')
    else:
        print('[*] Clean exit.')
    finally:
        print('[*] Finished...')