open-vault/website/source/docs/secrets/cassandra/index.html.md

layout	page_title	sidebar_current	description
docs	Cassandra Secret Backend	docs-secrets-cassandra	The Cassandra secret backend for Vault generates database credentials to access Cassandra.

Cassandra Secret Backend

Name: cassandra

~> Deprecation Note: This backend is deprecated in favor of the combined databases backend added in v0.7.1. See the documentation for the new implementation of this backend at Cassandra Database Plugin.

The Cassandra secret backend for Vault generates database credentials dynamically based on configured roles. This means that services that need to access a database no longer need to hardcode credentials: they can request them from Vault, and use Vault's leasing mechanism to more easily roll keys.

Additionally, it introduces a new ability: with every service accessing the database with unique credentials, it makes auditing much easier when questionable data access is discovered: you can track it down to the specific instance of a service based on the Cassandra username.

This page will show a quick start for this backend. For detailed documentation on every path, use vault path-help after mounting the backend.

Quick Start

The first step to using the Cassandra backend is to mount it. Unlike the generic backend, the cassandra backend is not mounted by default.

$ vault mount cassandra
Successfully mounted 'cassandra' at 'cassandra'!

Next, Vault must be configured to connect to Cassandra. This is done by writing one or more hosts, a username, and a password:

$ vault write cassandra/config/connection \
    hosts=localhost \
    username=cassandra \
    password=cassandra

In this case, we've configured Vault with the user "cassandra" and password "cassandra", It is important that the Vault user is a superuser, in order to manage other user accounts.

The next step is to configure a role. A role is a logical name that maps to a policy used to generated those credentials. For example, lets create a "readonly" role:

$ vault write cassandra/roles/readonly \
    creation_cql="CREATE USER '{{username}}' WITH PASSWORD '{{password}}' NOSUPERUSER; \
    GRANT SELECT ON ALL KEYSPACES TO {{username}};"
Success! Data written to: cassandra/roles/readonly

By writing to the roles/readonly path we are defining the readonly role. This role will be created by evaluating the given creation_cql statements. By default, the {{username}} and {{password}} fields will be populated by Vault with dynamically generated values. This CQL statement is creating the named user, and then granting it SELECT or read-only privileges to keyspaces. More complex GRANT queries can be used to customize the privileges of the role. See the CQL Reference Manual for more information.

To generate a new set of credentials, we simply read from that role: Vault is now configured to create and manage credentials for Cassandra!

$ vault read cassandra/creds/readonly
Key           	Value
lease_id       	cassandra/creds/test/7a23e890-3a26-531d-529b-92d18d1fa63f
lease_duration 	3600
lease_renewable	true
password       	dfa80eea-ccbe-b228-ebf7-e2f62b245e71
username       	vault-root-1434647667-9313

By reading from the creds/readonly path, Vault has generated a new set of credentials using the readonly role configuration. Here we see the dynamically generated username and password, along with a one hour lease.

Using ACLs, it is possible to restrict using the cassandra backend such that trusted operators can manage the role definitions, and both users and applications are restricted in the credentials they are allowed to read.

If you get stuck at any time, simply run vault path-help cassandra or with a subpath for interactive help output.

API

The Cassandra secret backend has a full HTTP API. Please see the Cassandra secret backend API for more details.