Does class MongoDBBackend accept a password parameter?

[oshihirii]

In OpenShift, the standard way to login to MongoDB is with environment variables:

dbname = 'mydbname'
connection = pymongo.MongoClient(os.environ['OPENSHIFT_MONGODB_DB_URL'])
db = connection[dbname]

The environment variable OPENSHIFT_MONGODB_DB_URL consists of:

OPENSHIFT_MONGODB_DB_URL=mongodb://admin:password-here@127.x.xx.xxx:27017/

You can also access these environment variables which are self explanatory:

OPENSHIFT_MONGODB_DB_USERNAME
OPENSHIFT_MONGODB_DB_PASSWORD
OPENSHIFT_MONGODB_DB_HOST
OPENSHIFT_MONGODB_DB_PORT

But in any case, in OpenShift, you have to provide a password to access MongoDB.

I am editing mongodb_backend.py so that it can connect to the database at line 138:

class MongoDBBackend(Backend):
    def __init__(self, db_name='cork', hostname='localhost', port=27017, initialize=False):
    """Initialize MongoDB Backend"""
    connection = MongoClient(host=hostname, port=port)
    db = connection[db_name]

How can I add a password parameter to this class?

(I am a bit of a newb with this, and trying to document my process as I go on the wiki so simple information appreciated if possible - thanks!)

[FedericoCeratto]

See: http://api.mongodb.org/python/current/api/pymongo/mongo_client.html
"The host parameter can be a full mongodb URI, in addition to a simple hostname."
And: http://docs.mongodb.org/manual/reference/connection-string/

[oshihirii]

Could I therefore use:

class MongoDBBackend(Backend):
    def __init__(self, db_name='cork', hostname='os.environ[\'OPENSHIFT_MONGODB_DB_URL\']', initialize=False):
    """Initialize MongoDB Backend"""
    connection = MongoClient(hostname)
    db = connection[db_name]

Two things I am confused about:

• Is the syntax correct for hostname value?
• Would each user therefore be accessing a connection where they were logged in with the MongoDB admin username and password (as that is all in the OPENSHIFT_MONGODB_DB_URL environment variable - see first post)? And if so is that a problem?

Sorry for asking so many questions, but I seem to be coming up against a few issues when implementing. Nevertheless, I hope they may be helpful for others implementing on OpenShift.

[FedericoCeratto]

No need to modify mongodb_backend.py - in your own code you can do:

dbname = 'mydbname'
hostname = os.environ['OPENSHIFT_MONGODB_DB_URL']
port = os.environ['OPENSHIFT_MONGODB_DB_PORT']
port = int(port)
connection = pymongo.MongoClient(hostname=hostname, port=port)
db = connection[dbname]

"connection" would be used by any user within the same application. It should have limited access rights, e.g. update the collection that belong to your webapp and nothing more.

[oshihirii]

Thank you for the clarification, that makes sense to me.

[oshihirii]

I ran my application from shell and got error:

  File "mybottleapp.py", line 47, in populate_mongodb_backend
    connection = pymongo.MongoClient(hostname=hostname)
NameError: global name 'hostname' is not defined

Looking at the class definition of MongoDBBackend in mongodb_backend.py, 'hostname' is defined as a parameter.

This is the code in my application:

def populate_mongodb_backend():
    mb = MongoDBBackend(db_name='cork-example', initialize=True,
            hostname = os.environ['OPENSHIFT_MONGODB_DB_URL'],
            connection = pymongo.MongoClient(hostname=hostname)
            )

Note the value of OPENSHIFT_MONGODB_DB_URL is:

mongodb://admin:password-here@127.x.xx.xxx:27017/

Update:

I realised host is the MongoClient parameter name, not hostname, so I tried:

def populate_mongodb_backend():
    mb = MongoDBBackend(db_name='cork-example', initialize=True,
            hostname = os.environ['OPENSHIFT_MONGODB_DB_URL'],
            connection = pymongo.MongoClient(host=hostname)
            )

And get the same error:

    connection = pymongo.MongoClient(host=hostname)
NameError: global name 'hostname' is not defined

[FedericoCeratto]

That's because the "hostname" variable is not defined. Use:
hostname = os.environ['OPENSHIFT_MONGODB_DB_URL']

[oshihirii]

working code:

def populate_mongodb_backend():
    hostname = os.environ['OPENSHIFT_MONGODB_DB_URL']
    connection = pymongo.MongoClient(host=hostname)
    mb = MongoDBBackend(db_name='cork-example', initialize=True,hostname = hostname)
    .... # the rest is the same