Cassandra example connection

cassandra.py

"""
Import the cassandra libraries that will be needed to connect to the cassandra cluster.

Note: Currently the cassandra-driver is only available for python 2.7 on conda-forge

Example install of package
conda install -c conda-forge cassandra-driver
"""
from cassandra.auth import PlainTextAuthProvider
from cassandra.cluster import Cluster


import json


# Get credentials from kubernetes. The credentials were setup as a dictionary
credentials = None
with open('/var/run/secrets/user_credentials/cassandra_credentials') as f:
    credentials = json.load(f)

# Check and make sure the credentials were pulled correctly
if credentials:
    # Setup authentication mechanism
    auth_provider = PlainTextAuthProvider(
        username=credentials.get('username'),
        password=credentials.get('password')
    )

    # Pass parameters to the cluster
    cluster = Cluster(
        auth_provider=auth_provider,
        contact_points=['support-cassandra.dev.anaconda.com']
    )

    # COnnect to cluster and set the keyspace
    session = cluster.connect()
    session.set_keyspace('quote')

    # Run query in keyspace and print out the results
    rows = session.execute('SELECT * FROM historical_prices')
    for row in rows:
        print(row)

    # Disconnect from the cluster
    cluster.shutdown()