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open-vault/website/source/docs/secrets/cassandra/index.html.md
Jeff Mitchell af73d965a4 Cassandra: 
* Add ability to change protocol version
* Remove config as a root path, use normal ACLs
* Update docs
2016-02-01 10:27:26 -05:00

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docs Secret Backend: Cassandra docs-secrets-cassandra The Cassandra secret backend for Vault generates database credentials to access Cassandra.

Cassandra Secret Backend

Name: cassandra

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

/cassandra/config/connection

POST

Description
Configures the connection information used to communicate with Cassandra. TLS works as follows:

  • • If `tls` is set to true, the connection will use TLS; this happens automatically if `pem_bundle`, `pem_json`, or `insecure_tls` is set
  • • If `insecure_tls` is set to true, the connection will not perform verification of the server certificate; this also sets `tls` to true
  • • If only `issuing_ca` is set in `pem_json`, or the only certificate in `pem_bundle` is a CA certificate, the given CA certificate will be used for server certificate verification; otherwise the system CA certificates will be used
  • • If `certificate` and `private_key` are set in `pem_bundle` or `pem_json`, client auth will be turned on for the connection
`pem_bundle` should be a PEM-concatenated bundle of a private key + client certificate, an issuing CA certificate, or both. `pem_json` should contain the same information; for convenience, the JSON format is the same as that output by the issue command from the PKI backend.
Method
POST
URL
`/cassandra/config/connection`
Parameters
  • hosts required A set of comma-deliniated Cassandra hosts to connect to.
  • username required The username to use for superuser access.
  • password required The password corresponding to the given username.
  • tls optional Whether to use TLS when connecting to Cassandra.
  • insecure_tls optional Whether to skip verification of the server certificate when using TLS.
  • pem_bundle optional Concatenated PEM blocks containing a certificate and private key; a certificate, private key, and issuing CA certificate; or just a CA certificate.
  • pem_json optional JSON containing a certificate and private key; a certificate, private key, and issuing CA certificate; or just a CA certificate. For convenience format is the same as the output of the `issue` command from the `pki` backend; see [the pki documentation](https://www.vaultproject.io/docs/secrets/pki/index.html).
  • protocol_version optional The CQL protocol version to use. Defaults to 2.
Returns
A `204` response code.

/cassandra/roles/

POST

Description
Creates or updates the role definition.
Method
POST
URL
`/cassandra/roles/`
Parameters
  • creation_cql optional The CQL statements executed to create and configure the new user. Must be semi-colon separated. The '{{username}}' and '{{password}}' values will be substituted; it is required that these parameters are in single quotes. The default creates a non-superuser user with no authorization grants.
  • rollback_cql optional The CQL statements executed to attempt a rollback if an error is encountered during user creation. The default is to delete the user. Must be semi-colon separated. The '{{username}}' and '{{password}}' values will be substituted; it is required that these parameters are in single quotes.
  • lease optional The lease value provided as a string duration with time suffix. Hour is the largest suffix.
Returns
A `204` response code.

GET

Description
Queries the role definition.
Method
GET
URL
`/cassandra/roles/`
Parameters
None
Returns
```javascript
{
  "data": {
    "creation_cql": "CREATE USER...",
    "rollback_cql": "DROP USER...",
    "lease": "12h",
  }
}
```

DELETE

Description
Deletes the role definition.
Method
DELETE
URL
`/cassandra/roles/`
Parameters
None
Returns
A `204` response code.

/cassandra/creds/

GET

Description
Generates a new set of dynamic credentials based on the named role.
Method
GET
URL
`/cassandra/creds/`
Parameters
None
Returns
```javascript
{
  "data": {
    "username": "vault-root-1430158508-126",
    "password": "132ae3ef-5a64-7499-351e-bfe59f3a2a21"
  }
}
```