Mongo Adapter

A python implementation of a mongo adapter.

The idea is to make a base class that handles the connection to a mongod instance. It is nice to handle the connection in the same way for different python projects that involves a mongo database.

The Mongo Adapter takes a client as init argument and then we connect to a database with setup(database), fortunately mongo_adapter can handle the client part as well.

Example:

from mongo_adapter import MongoAdapter, get_client

db_name = 'test'
client = get_client()
adapter = MongoAdapter(client, db_name)

assert adapter.db_name == db_name

Testing

The package can be used for testing as well

Example:

from mongo_adapter import MongoAdapter, get_client
import mongomock

db_name = 'test'
uri = "mongomock://"
client = get_client(uri=uri)
adapter = MongoAdapter(client, db_name)

assert isinsance(client, mongomock.MongoClient)

installation

git:

git clone https://github.com/moonso/mongo_adapter
cd mongo_adapter
pip install --editable .

pip:

pip install mongo_adapter

Intended usage

The intended usage is here illustrated with an example

from mongo_adapter import MongoAdapter, get_client

class LibraryAdapter(MongoAdapter):
    def setup(self, db_name='library'):
        """Overrides the basic setup method"""
        if self.client is None:
            raise SyntaxError("No client is available")
        if self.db is None:
            self.db = self.client[db_name]
            self.db_name = db_name

        self.books_collection = self.db.book
        self.user_collection = self.db.book

    def add_book(self, title, author):
        """Add a book to the books collection"""
        result = self.books_collection.insert_one(
            {
                'title': title,
                'author': author
            }
        )
        return result

if __name__ == '__main__':
    client = get_client()
    adapter = LibraryAdapter(client, database='library')

    adapter.add_book('Moby Dick', 'Herman Melville')

API

Client

def check_connection(client):
    """Check if the mongod process is running

    Args:
        client(MongoClient)

    Returns:
        bool
    """

def get_client(host='localhost', port=27017, username=None, password=None,
              uri=None, mongodb=None, timeout=20):
    """Get a client to the mongo database

    Args:
        host(str): Host of database
        port(int): Port of database
        username(str)
        password(str)
        uri(str)
        timeout(int): How long should the client try to connect

    Returns:
        client(pymongo.MongoClient)

    """

Adapter

class MongoAdapter(object):
    """Adapter for communicating with a mongo database"""
    def __init__(self, client=None, db_name=None):
        """
        Args:
            client(MongoClient)
            db_name(str)
        """
        self.client = client
        self.db = None
        self.db_name = None
        if (db_name and client):
            self.setup(database)

    def init_app(self, app):
        """Setup via Flask"""
        host = app.config.get('MONGO_HOST', 'localhost')
        port = app.config.get('MONGO_PORT', 27017)
        self.db_name = app.config['MONGO_DBNAME']
        self.client = app.extensions['pymongo']['MONGO'][0]
        self.db = app.extensions['pymongo']['MONGO'][1]
        LOG.info("connecting to database: %s:%s/%s", host, port, self.db_name)
		self.setup(self.db_name)

    def setup(self, db_name):
        """Setup connection to a database

        Args:
            db_name(str)
            db(pymongo.Database)
        """
        if self.client is None:
            raise SyntaxError("No client is available")
        if self.db is None:
            self.db = self.client[db_name]
            self.db_name = db_name
        LOG.info("Use database %s", self.db_name)