Caravel Documentation

Installation & Configuration

Getting Started

Caravel is currently only tested using Python 2.7.*. Python 3 support is on the roadmap, Python 2.6 won’t be supported.

Follow these few simple steps to install Caravel.:

# Install caravel
pip install caravel

# Create an admin user
fabmanager create-admin --app caravel

# Initialize the database
caravel db upgrade

# Create default roles and permissions
caravel init

# Load some data to play with
caravel load_examples

# Start the development web server
caravel runserver -d

After installation, you should be able to point your browser to the right hostname:port [http://localhost:8088](http://localhost:8088), login using the credential you entered while creating the admin account, and navigate to Menu -> Admin -> Refresh Metadata. This action should bring in all of your datasources for Caravel to be aware of, and they should show up in Menu -> Datasources, from where you can start playing with your data!

Configuration

To configure your application, you need to create a file (module) caravel_config.py and make sure it is in your PYTHONPATH. Here are some of the parameters you can copy / paste in that configuration module:

#---------------------------------------------------------
# Caravel specifix config
#---------------------------------------------------------
ROW_LIMIT = 5000
WEBSERVER_THREADS = 8

CARAVEL_WEBSERVER_PORT = 8088
#---------------------------------------------------------

#---------------------------------------------------------
# Flask App Builder configuration
#---------------------------------------------------------
# Your App secret key
SECRET_KEY = '\2\1thisismyscretkey\1\2\e\y\y\h'

# The SQLAlchemy connection string.
SQLALCHEMY_DATABASE_URI = 'sqlite:////tmp/caravel.db'

# Flask-WTF flag for CSRF
CSRF_ENABLED = True

# Whether to run the web server in debug mode or not
DEBUG = True

This file also allows you to define configuration parameters used by Flask App Builder, the web framework used by Caravel. Please consult the Flask App Builder Documentation for more information on how to configure Caravel.

Caching

Caravel uses Flask-Cache for caching purpose. Configuring your caching backend is as easy as providing a CACHE_CONFIG, constant in your caravel_config.py that complies with the Flask-Cache specifications.

Flask-Cache supports multiple caching backends (Redis, Memcache, SimpleCache (in-memory), or the local filesystem).

For setting your timeouts, this is done in the Caravel metadata and goes up the “timeout searchpath”, from your slice configuration, to your data source’s configuration, to your database’s and ultimately falls back into your global default defined in CACHE_CONFIG.

Druid

  • From the UI, enter the information about your clusters in the

    Admin->Clusters menu by hitting the + sign.

  • Once the Druid cluster connection information is entered, hit the

    Admin->Refresh Metadata menu item to populate

  • Navigate to your datasources