settings.py

import os
basedir = os.path.abspath(os.path.dirname(__file__))

class Config():
    SECRET_KEY = os.environ.get('SECRET KEY') or 'Jai guru deva om'
    MAIL_SERVER = os.environ.get('MAIL_SERVER', 'smtp.googlemail.com')
    MAIL_PORT = int(os.environ.get('MAIL_PORT', '587'))
    MAIL_USE_TLS = os.environ.get('MAIL_USE_TLS', 'true').lower() in \
        ['true', 'on', '1']
    MAIL_USERNAME = os.environ.get('MAIL_USERNAME')
    MAIL_PASSWORD = os.environ.get('MAIL_PASSWORD')
    MARIO_SUBJECT_PREFIX = "Welcome to Mario's blog!"
    MARIO_MAIL_SENDER = "coderlyonma@gmail.com"
    ADMIN_MARIO = "coderlyonma@gmail.com"
    SQLALCHEMY_TRACK_MODIFICATIONS = False
    SQLALCHEMY_RECORD_QUIRIES = True
    BLOG_SLOW_DB_QUERY_TIME = 0.5
    BLOG_POSTS_PER_PAGE = 10
    BLOG_FOLLOWERS_PER_PAGE = 20
    BLOG_COMMENTS_PER_PAGE = 10
    SSL_REDIRECT = False
    
    @staticmethod
    def init_app(app):
        pass
    
class DevelopmentConfig(Config):
    DEBUG = True
    SQLALCHEMY_DATABASE_URI = os.environ.get('DEV_DATABASE_URI') or \
        'sqlite:///' + os.path.join(basedir, 'data-dev.sqlite')


class TestingConfig(Config):
    TESTING = True
    SQLALCHEMY_DATABASE_URI = os.environ.get('TEST_DATABASE_URI') or \
        'sqlite://'
    WTF_CSRF_ENABLED = False


class ProductionConfig(Config):
    SQLALCHEMY_DATABASE_URI = os.environ.get('HEROKU_POSTGRESQL_GREEN_URL') or \
        'sqlite:///' + os.path.join(basedir, 'data.sqlite')

    @classmethod
    def init_app(cls, app):
        Config.init_app(app)

        # notice admin when things go wrong
        import logging
        from logging.handlers import SMTPHandler
        credentials = None
        secure = None
        if getattr(cls, 'MAIL_USERNAME', None) is not None:
            credentials = (cls.MAIL_USERNAME, cls.MAIL_PASSWORD)
            if getattr(cls, 'MAIL_USE_TLS', None):
                secure = ()
        mail_handler = SMTPHandler(
            mailhost=(cls.MAIL_SERVER, cls.MAIL_PORT),
            fromaddr=cls.MARIO_MAIL_SENDER,
            toaddrs=[cls.ADMIN_MARIO],
            subject=cls.MARIO_SUBJECT_PREFIX + ' Application Error',
            credentials=credentials,
            secure=secure)
        mail_handler.setLevel(logging.ERROR)
        app.logger.addHandler(mail_handler)

class HerokuConfig(ProductionConfig):
    @classmethod
    def init_app(cls, app):

        # output to stderr
        import logging
        from logging import StreamHandler
        file_handler = StreamHandler()
        file_handler.setLevel(logging.INFO)
        app.logger.addHandler(file_handler)
        SSL_REDIRECT = True if os.environ.get('DYNO') else False

        # dealing with reversing proxy
        from werkzeug.contrib.fixers import ProxyFix
        app.wsgi_app = ProxyFix(app.wsgi_app)


config = {
    'development': DevelopmentConfig,
    'testing': TestingConfig,
    'production': ProductionConfig,
    'heroku':HerokuConfig,
    
    'default': DevelopmentConfig
}