__init__.py

#!/usr/bin/env python
# Copyright (c) 2016 Jonathan Yantis
#
# Permission is hereby granted, free of charge, to any person obtaining a copy of
# this software and associated documentation files (the "Software"), to deal in
# the Software without restriction, including without limitation the rights to
# use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
# the Software, and to permit persons to whom the Software is furnished to do so,
# subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
# FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
# COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
# IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#
"""
Flask API Server
"""
import sys
import os
import re
import logging
from logging.handlers import RotatingFileHandler
import configparser
from flask import Flask, jsonify, request, g, make_response
from flask_httpauth import HTTPBasicAuth
from flask_limiter import Limiter
from flask_limiter.util import get_remote_address
from flask_sqlalchemy import SQLAlchemy

logger = logging.getLogger(__name__)

# Populated from config file
debug = 0

# Flask Limits for Safety
flask_limits = ["1000 per day", "100 per hour", "5 per minute"]

def override_config(cfg):
    """ Override/Add config file variables from environment
        Note: Only adds variables if [section] exists
    """

    for en in os.environ:
        oride = re.search(r'^APISRV_([a-zA-Z]+)_(\w+)', en)
        if oride:
            if oride.group(1) in cfg:
                #print('APISRV Override', oride.group(1), oride.group(2), os.environ[en])
                cfg[oride.group(1)][oride.group(2)] = os.environ[en]

    return cfg

# Initialize Configuration
config_file = 'apisrv.ini'

# Environment Override
if 'APISRV_config_file' in os.environ:
    config_file = os.environ['APISRV_config_file']

config = configparser.ConfigParser()
config.read(config_file)

# Override config file from environment variables
config = override_config(config)


# Check for sane config file
if 'apisrv' not in config:
    print("Could not parse config file: " + config_file)
    sys.exit(1)

# Logging Configuration, default level INFO
logger = logging.getLogger('')
logger.setLevel(logging.INFO)
lformat = logging.Formatter('%(asctime)s %(name)s:%(levelname)s: %(message)s')

# Debug mode Enabled
if 'debug' in config['apisrv'] and int(config['apisrv']['debug']) != 0:
    debug = int(config['apisrv']['debug'])
    logger.setLevel(logging.DEBUG)
    logging.debug('Enabled Debug mode')

# Enable logging to file if configured
if 'logfile' in config['apisrv']:
    lfh = RotatingFileHandler(config['apisrv']['logfile'], maxBytes=(1048576*5), backupCount=3)
    lfh.setFormatter(lformat)
    logger.addHandler(lfh)

# STDOUT Logging defaults to Warning
if not debug:
    lsh = logging.StreamHandler(sys.stdout)
    lsh.setFormatter(lformat)
    lsh.setLevel(logging.WARNING)
    logger.addHandler(lsh)

# Create Flask APP
app = Flask(__name__)
app.config.from_object(__name__)
app.config.update(dict(
    DATABASE=os.path.join(app.root_path, config['apisrv']['database']),
    SQLALCHEMY_DATABASE_URI='sqlite:///' + \
        os.path.join(app.root_path, config['apisrv']['database']),
    SQLALCHEMY_TRACK_MODIFICATIONS=False,
))

# Auth module
auth = HTTPBasicAuth()

# Database module
db = SQLAlchemy(app)

# Apply Rate limiting
limiter = Limiter(
    app,
    key_func=get_remote_address,
    global_limits=flask_limits
)

# Not Required with SQLAlchemy
# @app.teardown_appcontext
# def close_db(error):
#     """Closes the database again at the end of the request."""
#     db.remove()


# Safe circular imports per Flask guide
import apisrv.errors
import apisrv.views
import apisrv.user