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Iceberg Data Connector

The Iceberg Data Connector helps query Apache Iceberg tables using federated SQL. Every Iceberg dataset requires an Iceberg catalog to provide table metadata and manage access.

When working with multiple datasets, it is recommended to use a catalog connector (instead of a data connector), such as the Iceberg Catalog Connector or AWS Glue Catalog Connector instead of configuring individual datasets.

Iceberg catalogs can be of several types:

  • Iceberg REST Catalog: The most common and recommended approach. REST Catalogs expose Iceberg tables over HTTP(S) endpoints and are compatible with most managed Iceberg services and cloud providers.
  • AWS Glue Catalog: Integrates with AWS Glue as a catalog provider, supporting Iceberg tables stored in S3. This is the preferred method for AWS environments.
  • Hadoop-style Catalogs: Use file-based storage (e.g., file://, s3://, s3a://) to manage table metadata. This approach is typically used for local development or legacy deployments.
Hadoop-style Catalogs

For production and cloud environments, REST and AWS Glue catalogs are recommended. Hadoop-style catalogs are supported but less common and not recommended for most new deployments.

datasets:
  - from: iceberg:https://iceberg-catalog-host.com/v1/namespaces/my_namespace/tables/my_table
    name: my_table

Configuration​

from​

The from field specifies the Iceberg table to connect to, in the format iceberg:<table_path>. The table_path is the URL to the Iceberg table in the catalog provider. For REST Catalogs, use the format http[s]://<iceberg_catalog_host>/v1/{prefix}/namespaces/<namespace_name>/tables/<table_name>. For AWS Glue catalogs, the URL format is https://glue.<region>.amazonaws.com/iceberg/v1/catalogs/<account_id>/namespaces, where <account_id> is the AWS account ID. While possible to connect to Iceberg tables hosted by Glue using this generic connector, it is recommended to instead use the AWS Glue Data Connector for connecting to Iceberg tables managed by Glue for a better experience.

Example (REST Catalog):

datasets:
  - from: iceberg:https://iceberg-catalog-host.com/v1/namespaces/my_namespace/tables/my_table
    name: my_table

Example (AWS Glue Catalog):

datasets:
  - from: iceberg:https://glue.us-east-1.amazonaws.com/iceberg/v1/catalogs/123456789012/namespaces/my_namespace/tables/my_table
    name: glue_table

Hadoop-style catalogs use file-based paths such as file://, s3://, or s3a://. For these, specify the warehouse path as the table location. This is typically only used for local development or legacy setups.

Example (Hadoop Catalog, local):

datasets:
  - from: iceberg:file:///tmp/hadoop_warehouse/test/my_table_1
    name: local_hadoop

Example (Hadoop Catalog, S3):

datasets:
  - from: iceberg:s3a://my-bucket/hadoop_warehouse/test/my_table_2
    name: s3_hadoop

name​

The name field sets the table name within Spice. This name is used to reference the dataset in SQL queries. The name cannot be a reserved keyword.

Example:

datasets:
  - from: iceberg:https://iceberg-catalog-host.com/v1/namespaces/my_namespace/tables/my_table
    name: transactions
    params:
      iceberg_token: ${secrets:iceberg_token}
SELECT COUNT(*) FROM transactions;
+----------+
| count(*) |
+----------+
| 1234567  |
+----------+

params​

Parameter NameDescription
iceberg_tokenBearer token value to use for Authorization header.
iceberg_oauth2_credentialCredential to use for OAuth2 client credential flow when connecting to the table. Format: <client_id>:<client_secret>
iceberg_oauth2_scopeScope to use for OAuth2 client credential flow when connecting to the table. Default: catalog
iceberg_oauth2_server_urlURL of the OAuth2 server tokens endpoint for the client credential flow.
iceberg_s3_endpointS3-compatible endpoint where the Iceberg table data is stored.
iceberg_s3_regionRegion of the S3-compatible endpoint.
iceberg_s3_access_key_idThe AWS access key ID to use for S3 storage. If not provided, credentials will be loaded from environment variables or IAM roles.
iceberg_s3_secret_access_keyThe AWS secret access key to use for S3 storage. If not provided, credentials will be loaded from environment variables or IAM roles.
iceberg_s3_session_tokenSession token for the S3-compatible endpoint.
iceberg_s3_role_arnARN of the IAM role to assume when accessing the S3-compatible endpoint.
iceberg_s3_role_session_nameSession name to use when assuming the IAM role.
iceberg_s3_connect_timeoutConnection timeout in seconds for the S3-compatible endpoint. Default: 60
iceberg_sigv4_enabledEnable SigV4 (AWS Signature Version 4) authentication when connecting to the catalog. Automatically enabled if the URL in from is an AWS Glue catalog. Default: false
iceberg_signing_regionRegion to use for SigV4 authentication. Extracted from the URL in from if not specified.
iceberg_signing_nameService name to use for SigV4 authentication. Default: glue.
metadata_pathThe path including scheme to the metadata file for the Hadoop table. Must specify a path to a .json file. For example, s3a://my-bucket/warehouse/namespace/table/metadata/v1.metadata.json

Authentication​

Authentication to the Iceberg catalog. Supported methods include:

  • Bearer Token: Use iceberg_token for Authorization header.
  • OAuth2 Client Credentials: Use iceberg_oauth2_credential, iceberg_oauth2_scope, and iceberg_oauth2_server_url.
  • AWS SigV4: For AWS Glue, set iceberg_sigv4_enabled: true (or use a Glue URL).
  • S3 Authentication: Use iceberg_s3_* parameters for S3 data access.

AWS Authentication​

If AWS credentials are not explicitly provided in the configuration, the connector will automatically load credentials from the following sources in order. These credentials will be used to connect to the S3 bucket as well as the Glue catalog (if configured).

  1. Environment Variables:

    • AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY
    • AWS_SESSION_TOKEN (if using temporary credentials)

  2. Shared AWS Config/Credentials Files:

    • Config file: ~/.aws/config (Linux/Mac) or %UserProfile%\.aws\config (Windows)

    • Credentials file: ~/.aws/credentials (Linux/Mac) or %UserProfile%\.aws\credentials (Windows)

    • The AWS_PROFILE environment variable can be used to specify a named profile, otherwise the [default] profile is used.

    • Supports both static credentials and SSO sessions

    • Example credentials file:

      # Static credentials
      [default]
      aws_access_key_id = YOUR_ACCESS_KEY
      aws_secret_access_key = YOUR_SECRET_KEY

      # SSO profile
      [profile sso-profile]
      sso_start_url = https://my-sso-portal.awsapps.com/start
      sso_region = us-west-2
      sso_account_id = 123456789012
      sso_role_name = MyRole
      region = us-west-2
    tip

    To set up SSO authentication:

    1. Run aws configure sso to configure a new SSO profile
    2. Use the profile by setting AWS_PROFILE=sso-profile
    3. Run aws sso login --profile sso-profile to start a new SSO session

  3. AWS STS Web Identity Token Credentials:

    • Used primarily with OpenID Connect (OIDC) and OAuth
    • Common in Kubernetes environments using IAM roles for service accounts (IRSA)

  4. ECS Container Credentials:

    • Used when running in Amazon ECS containers
    • Automatically uses the task's IAM role
    • Retrieved from the ECS credential provider endpoint
    • Relies on the environment variable AWS_CONTAINER_CREDENTIALS_RELATIVE_URI or AWS_CONTAINER_CREDENTIALS_FULL_URI which are automatically injected by ECS.

  5. AWS EC2 Instance Metadata Service (IMDSv2):

    • Used when running on EC2 instances.
    • Automatically uses the instance's IAM role.
    • Retrieved securely using IMDSv2.

The connector will try each source in order until valid credentials are found. If no valid credentials are found, an authentication error will be returned.

IAM Permissions

Regardless of the credential source, the IAM role or user must have appropriate S3/Glue permissions (e.g., s3:ListBucket, s3:GetObject) to access the tables. If the Spicepod connects to multiple different AWS services, the permissions should cover all of them.

Required IAM Permissions​

The IAM role or user needs the following permissions to access Iceberg tables in S3/Glue:

{
    "Version": "2012-10-17",
    "Statement": [
      {
        "Effect": "Allow",
        "Action": ["s3:ListBucket"],
        "Resource": "arn:aws:s3:::company-bucketname-datasets"
      },
      {
        "Effect": "Allow",
        "Action": ["s3:GetObject"],
        "Resource": "arn:aws:s3:::company-bucketname-datasets/*"
      },
      {
        "Effect": "Allow",
        "Action": [
          "glue:GetCatalog",
          "glue:GetDatabases",
          "glue:GetDatabase",
          "glue:GetTable",
          "glue:GetTables"
        ],
        Resource: "*"
      }
    ]
}

Permission Details​

PermissionPurpose
s3:ListBucketRequired. Allows scanning all objects from the bucket
s3:GetObjectRequired. Allows fetching objects
glue:GetCatalogRequired. Retrieve metadata about the specified catalog.
glue:GetDatabasesRequired. List the databases available in the current catalog.
glue:GetDatabaseRequired. Retrieve metadata about the specified database.
glue:GetTableRequired. Retrieve metadata about the specified table.
glue:GetTablesRequired. List the tables available in the current database.

Examples​

Basic Example (REST Catalog)​

Connect to an Iceberg table with token authentication:

datasets:
  - from: iceberg:https://iceberg-catalog-host.com/v1/namespaces/my_namespace/tables/my_table
    name: my_table
    params:
      iceberg_token: ${secrets:iceberg_token}

AWS Glue Catalog Example​

Connect to an Iceberg table in AWS Glue catalog:

datasets:
  - from: iceberg:https://glue.us-east-1.amazonaws.com/iceberg/v1/catalogs/123456789012/namespaces/my_namespace/tables/my_table
    name: glue_table
    params:
      iceberg_sigv4_enabled: true

OAuth2 Authentication Example​

Connect to an Iceberg table using OAuth2 authentication:

datasets:
  - from: iceberg:https://iceberg-catalog-host.com/v1/namespaces/my_namespace/tables/my_table
    name: oauth_table
    params:
      iceberg_oauth2_credential: ${secrets:client_id}:${secrets:client_secret}
      iceberg_oauth2_scope: catalog
      iceberg_oauth2_server_url: https://iceberg-catalog-host.com/oauth2/token

S3 Storage Example​

Connect to an Iceberg table with custom S3 storage configuration:

datasets:
  - from: iceberg:https://iceberg-catalog-host.com/v1/namespaces/my_namespace/tables/my_table
    name: s3_table
    params:
      iceberg_token: ${secrets:iceberg_token}
      iceberg_s3_endpoint: http://localhost:9000
      iceberg_s3_region: us-west-2
      iceberg_s3_access_key_id: ${secrets:aws_access_key_id}
      iceberg_s3_secret_access_key: ${secrets:aws_secret_access_key}

Hadoop Catalog Example​

Connect to an Iceberg table using Hadoop Catalog with a local warehouse:

datasets:
  - from: iceberg:file:///tmp/hadoop_warehouse/test/my_table_1
    name: local_hadoop
    params:
      metadata_path: file:///tmp/hadoop_warehouse/test/my_table_1/metadata/v1.metadata.json

Connect to an Iceberg table using Hadoop Catalog with S3:

datasets:
  - from: iceberg:s3a://my-bucket/hadoop_warehouse/test/my_table_2
    name: s3_hadoop
    params:
      metadata_path: s3a://my-bucket/hadoop_warehouse/test/my_table_2/metadata/v1.metadata.json

Secrets​

Spice integrates with multiple secret stores to help manage sensitive data securely. For detailed information on supported secret stores, refer to the secret stores documentation. Additionally, learn how to use referenced secrets in component parameters by visiting the using referenced secrets guide.

Limitations​

Performance Considerations

When querying Iceberg tables, performance depends on the size of the table, the complexity of the query, and the underlying storage system. For large tables, consider using appropriate filtering to limit the amount of data scanned.

The connector needs to access both the Iceberg catalog metadata and the underlying data files (typically stored in S3 or a compatible object store). Ensure proper network connectivity and authentication for both systems.