ACL Permissions


Permissions determine the access level that users and groups have on objects. These are represented via streamsets.sdk.sch_models.ACL definitions (ACLs), which contain a list of streamsets.sdk.sch_models.Permission instances for each subject. A streamsets.sdk.sch_models.Permission instance stores the actions a user can take on the object.

ACL permissions exist for numerous objects in Control Hub, including Execution Engines, Pipelines and Fragments, Jobs, Provisioning Agents and Deployments, Topologies, Connections, Reports, Scheduled Tasks, and Subscriptions.

Tip

Accessing the ACL definition is the same for all objects in the SDK, regardless of their type. While not all objects have an ACL, objects that do have ACL permissions will always have them stored under the acl attribute. Likewise, the ACL will always have the same structure of one permission definition per subject.

Find out more on Permissions in the Control Hub Documentation.

Retrieving an object’s ACL permissions

To retrieve an object’s streamsets.sdk.sch_models.ACL definition, you can reference the acl attribute of the object. For example, to retrieve the ACL permissions of a streamsets.sdk.sch_models.Topology instance the following steps can be taken:

topology = sch.topologies.get(topology_name='ACL test topology')

# Show the ACL object for this Topology
topology.acl

# Show the specific permission definitions that are part of the ACL
topology.acl.permissions

Output:

# topology.acl
<ACL (resource_id=fe8f5ead-bee0-475f-b3b7-7875a89a6f0c:admin, resource_type=TOPOLOGY)>

# topology.acl.permissions
[<Permission (resource_id=fe8f5ead-bee0-475f-b3b7-7875a89a6f0c:admin, subject_type=USER, subject_id=admin@admin)>,
 <Permission (resource_id=fe8f5ead-bee0-475f-b3b7-7875a89a6f0c:admin, subject_type=USER, subject_id=user@admin)>,
 <Permission (resource_id=fe8f5ead-bee0-475f-b3b7-7875a89a6f0c:admin, subject_type=GROUP, subject_id=admin_group@admin)>]

You can inspect an individual ACL definition’s actions to see the level of access a particular user or group has to the resource:

# Get the permission definition for a specific subject, 'admin@admin' in this case
permission = topology.acl.permissions.get(subject_id='admin@admin')

# Show the actions that are set for that permission definition (the actions the user/group can take)
permission.actions

Output:

['READ', 'WRITE']

Executable objects, such as streamsets.sdk.sch_models.ReportDefinition or streamsets.sdk.sch_models.Job instances, also have an 'EXECUTE' action that indicates a user or group can execute the object in question, e.g. running a job or generating a report definition.

job = sch.jobs.get(name='Job for ACL pipeline')

# Get the permission definition for a specific subject, 'user@admin' in this case
permission = job.acl.permissions.get(subject_id='user@admin')

# Show the actions set for that permission definition (the actions the user/group can take)
permission.actions

Output:

['READ', 'WRITE', 'EXECUTE']

Adding new ACL permissions to an object

To create a new permission definition for a user or group on an object, the streamsets.sdk.sch_models.ACLPermissionBuilder class is used. While it is possible to instantiate a new streamsets.sdk.sch_models.ACLPermissionBuilder instance directly, most users will want to utilize the builder that is already included within the streamsets.sdk.sch_models.ACL definition of an object.

The permission builder can be accessed directly via the streamsets.sdk.sch_models.ACL.permission_builder attribute. It requires a subject_id, subject_type, and list of actions in order to build a permission definition. Once the permission definition has been built, pass the permission definition to the streamsets.sdk.sch_models.ACL.add_permission() method to add it to the object that owns the ACL:

pipeline = sch.pipelines.get(name='ACL pipeline')

# Retrieve the ACL definition of the pipeline
acl = pipeline.acl

# Create a list of actions to add for the new permission definition
actions = ['READ', 'WRITE']

# Build the new permission definition for the subject_id (username), subject_type (user or group) and the
# actions to allow for this subject.
permission = acl.permission_builder.build(subject_id='user@admin', subject_type='USER', actions=actions)

# Add the permission definition to the ACL
acl.add_permission(permission)

# Show that the permission definition was correctly added to the ACL
pipeline = sch.pipelines.get(name='ACL pipeline')
pipeline.acl.permissions.get(subject_id='user@admin').actions

Output:

['READ', 'WRITE']

Updating existing ACL permissions on an object

Updating an existing permission definition for an object’s ACL is similar to creating a new permission definition, but rather than building a brand new permission definition, you simply modify an existing one in-place. Retrieve the object you wish to modify the ACL permissions for, retrieve the specific permission definition you want to update, and modify the actions as needed:

pipeline = sch.pipelines.get(name='ACL pipeline')

# Retrieve the permission definition for the subject to be modified
permission = pipeline.acl.permissions.get(subject_id='user@admin')

# Create a list of new actions that the permission definition will use
updated_actions = ['READ']

# Set the actions for the permission to the new 'updated_actions' list
permission.actions = updated_actions

# Show that the permission definition was correctly added to the ACL
pipeline = sch.pipelines.get(name='ACL pipeline')
pipeline.acl.permissions.get(subject_id='user@admin').actions

Output:

['READ']

Removing ACL permissions on an object

To remove an existing permission definition, the streamset.sdk.sch_models.ACL.remove_permission() method is used. You’ll first need to retrieve the specific permission you wish to delete from the ACL, and then pass it into the method:

report_definition = sch.report_definitions.get(name='ACL test report')

# Retrieve the permission definition for the subject to be removed
permission = report_definition.acl.permissions.get(subject_id='user2@admin')

# Remove the permission definition from the ACL
report_definition.acl.remove_permission(permission)

Changing ownership of an object

An object’s ACL permissions also dictate who the owner of the object is. To inspect the owner, you can reference the resource_owner attribute of the ACL:

job = sch.jobs.get(job_name='Job for ACL test')

# Show the ACL object for this Job
job.acl

# Show the resource_owner for this Job, defined in the ACL
job.acl.resource_owner

Output:

# job.acl
<ACL (resource_id=890cccd2-ed8c-4416-88f7-d38a54844ab9:admin, resource_type=JOB)>

# job.acl.resource_owner
'admin@admin'

Changing ownership of an object is as simple as specifying a new resource owner in the ACL for the object. The resource owner value should be a valid user from the organization, specified in the 'user@organization' format. Continuing on from the sample above:

job.acl.resource_owner = 'user@admin'