Client Configuration¶

When Nessie is integrated into a broader data processing environment, authentication settings need to be provided in a way specific to the tool used.

Nessie client configuration options¶

See also Authentication Settings below.

Common settings¶

Network settings¶

HTTP settings¶

Bearer authentication settings¶

See also Authentication Settings below.

OAuth2 settings¶

See also Authentication Settings below.

OAuth2 Token Exchange settings¶

The Nessie client now supports token exchange, which allows the client to exchange an access token for another access token.

AWS authentication settings¶

Additional AWS authentication configuration should be provided via standard AWS configuration files.

See also Authentication Settings below.

Basic authentication settings¶

See also Authentication Settings below.

Java 11 connection pool options¶

The Java 11 HTTP client can be configured using Java system properties. Since Java’s HttpClient API does not support the configuration of these properties programmatically, Nessie cannot expose those via its configuration mechanism.

Spark¶

When Nessie is used in Spark-based environments (with Iceberg the Nessie authentication settings are configured via Spark session properties (Replace <catalog_name> with the name of your catalog).

// local spark instance, assuming NONE authentication
conf.set("spark.sql.catalog.<catalog_name>", "org.apache.iceberg.spark.SparkCatalog")
    .set("spark.sql.catalog.<catalog_name>.authentication.type", "NONE")
    .set(...);
spark = SparkSession.builder()
                    .master("local[2]")
                    .config(conf)
                    .getOrCreate();

# local spark instance, assuming NONE authentication
spark = SparkSession.builder \
        .config("spark.sql.catalog.<catalog_name>", "org.apache.iceberg.spark.SparkCatalog") \
        .config("spark.sql.catalog.<catalog_name>.authentication.type", "NONE") \
        .config(...) 
        .getOrCreate()

Property Prefixes¶

The spark.sql.catalog.<catalog_name> prefix identifies properties for the Nessie catalog. The <catalog_name> part is just the name of the catalog in this case (not to be confused with the Nessie project name).

Multiple Nessie catalogs can be configured in the same Spark environment, each with its own set of configuration properties and its own property name prefix.

Flink¶

When Nessie is used in Flink with Iceberg, the Nessie authentication settings are configured when creating the Nessie catalog in Flink (Replace <catalog_name> with the name of your catalog):

table_env.execute_sql(
        """CREATE CATALOG <catalog_name> WITH (
        'type'='iceberg',
        'catalog-impl'='org.apache.iceberg.nessie.NessieCatalog',
        'authentication.type'='NONE')""")

Authentication Settings¶

The sections below discuss specific authentication settings. The property names are shown without environment-specific prefixes for brevity. Nonetheless, in practice the property names should be given appropriate prefixes (as in the examples above) for them to be recognized by the tools and Nessie code.

The value of the authentication.type property can be one of the following:

• NONE (default)
• BEARER
• OAUTH2
• AWS

Authentication Type NONE¶

For the Authentication Type NONE only the authentication.type property needs to be set.

This is also the default authentication type if nothing else is configured.

Authentication Type BEARER¶

For the BEARER Authentication Type the authentication.token property should be set to a valid OpenID token.

This authentication type is recommended only when the issued access token has a lifespan large enough to cover the duration of the entire Nessie client’s session. Once the token is expired, the Nessie client will not be able to refresh it and will have to be restarted, with a different token. If the token needs to be refreshed periodically, then the OAUTH2 authentication type should be preferred to this one.

Authentication Type OAUTH2¶

The OAUTH2 Authentication Type is able to authenticate against an OAuth2 server and obtain a valid access token. Only Bearer access tokens are currently supported. The access token is then used to authenticate against Nessie. The client will automatically refresh the access token. This authentication type is recommended when the access token has a lifespan shorter than the Nessie client’s session lifespan.

Note that the Nessie server must be configured to accept OAuth2 tokens from the same server. For example, if the OAuth2 server is Keycloak, this can be done by defining the following properties in the application.properties file of the Nessie server:

nessie.server.authentication.enabled=true
quarkus.oidc.auth-server-url=https://<keycloak-server>/realms/<realm-name>

The most important property is authentication.oauth2.grant-type, which defines the grant type to use when authenticating against the OAuth2 server. Valid values are:

• client_credentials : enables the Client Credentials grant (default);
• password : enables the Resource Owner Password Credentials grant;
• authorization_code : enables the Authorization Code grant;
• device_code : enables the Device Authorization grant.

The full list of available properties is shown above.

Which grant type to use?¶

The “client_credentials” grant type is the simplest one, but it requires the client to be granted enough permissions to access the Nessie server on behalf of the user. This is not always possible, and should be avoided if the resource owner (the user) is a human.

The “password” grant type is also simple, but it requires passing the user’s password to the client, which may not be acceptable in some cases for security reasons.

For real users trying to authenticate within a terminal session, such as a Spark shell, the “authorization_code” grant type is recommended. It requires the user to authenticate in a browser window, thus sparing the need to provide the user’s password directly to the client. The user will be prompted to authenticate in a separate browser window, and the Nessie client will be notified when the authentication is complete.

If the terminal session is running remotely however, on inside an embedded device, then the “authorization_code” grant type may not be suitable, as the browser and the terminal session must be running on the same machine. In this case, the “device_code” grant type is recommended. Similar to the “authorization_code” grant type, it requires the user to authenticate in a browser window, but it does not require the browser and the terminal session to be running on the same machine. The user will be prompted to authenticate in a local browser window, and the remote Nessie client will poll the OAuth2 server for the authentication status, until the authentication is complete.