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Create an external location to connect cloud storage to Azure Databricks

  • Artikkeli

This article describes how to configure an external location in Unity Catalog to connect cloud storage to Azure Databricks.

External locations associate Unity Catalog storage credentials with cloud object storage containers. External locations are used to define managed storage locations for catalogs and schemas, and to define locations for external tables and external volumes.

You can create an external location that references storage in an Azure Data Lake Storage Gen2 storage container or Cloudflare R2 bucket.

You can create an external location using Catalog Explorer, the Databricks CLI, SQL commands in a notebook or Databricks SQL query, or Terraform.

For more information about the uses of external locations and the relationship between storage credentials and external locations, see Manage access to cloud storage using Unity Catalog.

Before you begin

Prerequisites:

Permissions requirements:

  • You must have the CREATE EXTERNAL LOCATION privilege on both the metastore and the storage credential referenced in the external location. Metastore admins have CREATE EXTERNAL LOCATION on the metastore by default.
  • If you are creating an external location for the DBFS root storage location, the system can create the storage credential for you, but you must be a workspace admin. For details, see Create an external location for data in DBFS root

Create an external location manually using Catalog Explorer

You can create an external location manually using Catalog Explorer.

Permissions and prerequisites: see Before you begin.

To create the external location:

  1. Log in to a workspace that is attached to the metastore.

  2. In the sidebar, click Catalog icon Catalog.

  3. On the Quick access page, click the External data > button, go to the External Locations tab, and click Create location.

  4. Enter an External location name.

  5. Under URL, enter or select the path to the external location. You have three options:

    • To copy the container path from an existing DBFS mount point, click Copy from DBFS.

    • To copy the subpath to the DBFS root storage location, click Copy from DBFS and select Copy from DBFS root. If you are a workspace admin, the system also creates the storage credential for you.

      See Create an external location for data in DBFS root.

    • If you aren’t copying from an existing mount point or DBFS root, use the URL field to enter the storage container or R2 bucket path that you want to use as the external location.

      For example, abfss://my-container-name@my-storage-account.dfs.core.windows.net/<path> or r2://my-bucket@my-account-id.r2.cloudflarestorage.com/<path>.

  6. Select the storage credential that grants access to the external location.

    Note

    If your external location is for the DBFS root and you are a workspace admin, the system creates the storage credential for you, and you do not need to select one.

    If you don’t have a storage credential, you can create one:

    1. In the Storage credential drop-down list, select + Create new storage credential.

    2. In the Credential type drop-down list, select the type of credential you want to use in the storage credential object: Azure Managed Identity or Cloudflare API token.

    3. For Azure Managed Identity, enter the access connector ID and (optionally) the user-assigned managed identity that give access to the storage location. For Cloudflare API tokens, enter the Cloudflare account, access key ID, and secret access key.

      For more information, see Create a storage credential for connecting to Azure Data Lake Storage Gen2 or Create a storage credential for connecting to Cloudflare R2.

  7. (Optional) If you want users to have read-only access to the external location, click Advanced Options and select Read only. For more information, see Mark an external location as read-only.

  8. (Optional) If the external location is intended for a Hive metastore federated catalog, click Advanced options and enable Fallback mode.

    See Enable fallback mode on external locations.

  9. Click Create.

  10. (Optional) Bind the external location to specific workspaces.

    By default, any privileged user can use the external location on any workspace attached to the metastore. If you want to allow access only from specific workspaces, go to the Workspaces tab and assign workspaces. See (Optional) Assign an external location to specific workspaces.

  11. Go to the Permissions tab to grant permission to use the external location.

    For anyone to use the external location you must grant permissions:

    • To use the external location to add a managed storage location to metastore, catalog, or schema, grant the CREATE MANAGED LOCATION privilege.
    • To create external tables or volumes, grant CREATE EXTERNAL TABLE or CREATE EXTERNAL VOLUME.
    1. Click Grant.
    2. On the Grant on <external location> dialog, select users, groups, or service principals in Principals field, and select the privilege you want to grant.
    3. Click Grant.

Create an external location using SQL

To create an external location using SQL, run the following command in a notebook or the SQL query editor. Replace the placeholder values. For required permissions and prerequisites, see Before you begin.

  • <location-name>: A name for the external location. If location_name includes special characters, such as hyphens (-), it must be surrounded by backticks (` `). See Names.

  • <bucket-path>: The path in your cloud tenant that this external location grants access to. For example, abfss://my-container-name@my-storage-account.dfs.core.windows.net/<path> or r2://my-bucket@my-account-id.r2.cloudflarestorage.com/<path>.

  • <storage-credential-name>: The name of the storage credential that authorizes reading from and writing to the storage container or bucket path. If the storage credential name includes special characters, such as hyphens (-), it must be surrounded by backticks (` `).

CREATE EXTERNAL LOCATION [IF NOT EXISTS] `<location-name>`
URL '<bucket-path>'
WITH ([STORAGE] CREDENTIAL `<storage-credential-name>`)
[COMMENT '<comment-string>'];

If you want to limit external location access to specific workspaces in your account, also known as workspace binding or external location isolation, see (Optional) Assign an external location to specific workspaces.

(Optional) Assign an external location to specific workspaces

Important

This feature is in Public Preview.

By default, an external location is accessible from all of the workspaces in the metastore. This means that if a user has been granted a privilege (such as READ FILES) on that external location, they can exercise that privilege from any workspace attached to the metastore. If you use workspaces to isolate user data access, you might want to allow access to an external location only from specific workspaces. This feature is known as workspace binding or external location isolation.

Typical use cases for binding an external location to specific workspaces include:

  • Ensuring that data engineers who have the CREATE EXTERNAL TABLE privilege on an external location that contains production data can create external tables on that location only in a production workspace.
  • Ensuring that data engineers who have the READ FILES privilege on an external location that contains sensitive data can only use specific workspaces to access that data.

For more information about how to restrict other types of data access by workspace, see Limit catalog access to specific workspaces.

Important

Workspace bindings are referenced at the point when privileges against the external location are exercised. For example, if a user creates an external table by issuing the statement CREATE TABLE myCat.mySch.myTable LOCATION 'abfss://my-container-name@storage-account-name.dfs.core.windows.net/finance' from the myWorkspace workspace, the following workspace binding checks are performed in addition to regular user privilege checks:

  • Is the external location covering 'abfss://my-container-name@storage-account-name.dfs.core.windows.net/finance' bound to myWorkspace?
  • Is the catalog myCat bound to myWorkspace with access level Read & Write?

If the external location is subsequently unbound from myWorkspace, then the external table continues to function.

This feature also allows you to populate a catalog from a central workspace and make it available to other workspaces using catalog bindings, without also having to make the external location available in those other workspaces.

Bind an external location to one or more workspaces

To assign an external location to specific workspaces, you can use Catalog Explorer or the Databricks CLI.

Permissions required: Metastore admin, external location owner, or MANAGE on the external location.

Note

Metastore admins can see all external locations in a metastore using Catalog Explorer—and external location owners can see all external locations that they own in a metastore—regardless of whether the external location is assigned to the current workspace. External locations that are not assigned to the workspace appear grayed out.

Catalog Explorer

  1. Log in to a workspace that is linked to the metastore.

  2. In the sidebar, click Catalog icon Catalog.

  3. On the Quick access page, click the External data > button to go to the External Locations tab.

  4. Select the external location and go to the Workspaces tab.

  5. On the Workspaces tab, clear the All workspaces have access checkbox.

    If your external location is already bound to one or more workspaces, this checkbox is already cleared.

  6. Click Assign to workspaces and enter or find the workspaces you want to assign.

To revoke access, go to the Workspaces tab, select the workspace, and click Revoke. To allow access from all workspaces, select the All workspaces have access checkbox.

CLI

There are two Databricks CLI command groups and two steps required to assign an external location to a workspace.

In the following examples, replace <profile-name> with the name of your Azure Databricks authentication configuration profile. It should include the value of a personal access token, in addition to the workspace instance name and workspace ID of the workspace where you generated the personal access token. See Azure Databricks personal access token authentication.

  1. Use the external-locations command group’s update command to set the external location’s isolation mode to ISOLATED:

    databricks external-locations update <my-location> \
--isolation-mode ISOLATED \
--profile <profile-name>

    The default isolation-mode is OPEN to all workspaces attached to the metastore.

  2. Use the workspace-bindings command group’s update-bindings command to assign the workspaces to the external location:

    databricks workspace-bindings update-bindings external-location <my-location> \
--json '{
  "add": [{"workspace_id": <workspace-id>}...],
  "remove": [{"workspace_id": <workspace-id>}...]
}' --profile <profile-name>

    Use the "add" and "remove" properties to add or remove workspace bindings.

    Note

    Read-only binding (BINDING_TYPE_READ_ONLY) is not available for external locations. Therefore there is no reason to set binding_type for the external locations binding.

To list all workspace assignments for an external location, use the workspace-bindings command group’s get-bindings command:

databricks workspace-bindings get-bindings external-location <my-location> \
--profile <profile-name>

See also Workspace Bindings in the REST API reference.

Unbind an external location from a workspace

Instructions for revoking workspace access to an external location using Catalog Explorer or the workspace-bindings CLI command group are included in Bind an external location to one or more workspaces.

Next steps