cdeploy

cdeploy is a simple tool to manage your Cassandra schema migrations in the style of dbdeploy

Installation

pip install cdeploy

Command Line Usage

By default, cdeploy will look for migrations in './migrations'. This can be overridden by passing the path to your migrations directory as the first argument:

cdeploy db/migrations

The migrations directory should contain CQL scripts using the following naming convention: [version]_migration_description.cql

For example:

migrations/
    001_create_orders_table.cql
    002_create_customers_table.cql

Version numbers should begin from 1. Migration scripts may contain multiple semicolon terminated CQL statements. Comment lines can begin with either "--" or "//".

Migrations can also specify how to revert the changes by including additional statements following a line containing "--//@UNDO". For example:

CREATE TABLE orders(
    order_id uuid PRIMARY KEY,
    price text
);

--//@UNDO

DROP TABLE orders;

To undo the most recently applied migration, run:

cdeploy --undo

Python Library Usage

    from cdeploy import migrator

    schema_migrator = migrator.Migrator('/path/to/migrations/directory', cassandra_session)
    schema_migrator.run_migrations()

Configuration

cdeploy will look in your migrations directory for a configuration file named cassandra.yml, in a subdirectory named config:

migrations/
   config/
       cassandra.yml

The configuration file specifies the hosts to connect to and the keyspace name, and supports multiple environments. For example:

development:
    hosts: [host1]
    keyspace: keyspace_name

production:
    hosts: [host1, host2, host3]
    keyspace: keyspace_name

The environment can be set via the ENV shell variable, and defaults to development if not specified:

ENV=production cdeploy

Additional configuration parameters for Cassandra are available:

development:
    hosts: [host1]
    keyspace: keyspace_name
    auth_enabled: true
    auth_username: username
    auth_password: password
    port: 9042
    ssl_enabled: true
    ssl_ca_certs: /path/to/ca/certs
    consistency_level: ALL
    timeout: 10