feat: Migration for legacy library permissions (openedx#134)

rodmgwgu · web-flow · commit 21a847c353e3 · 2025-11-18T11:08:18.000+01:00
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
@@ -16,6 +16,14 @@ Unreleased
 
 *
 
+0.18.0 - 2025-11-17
+********************
+
+Added
+=====
+
+* Migration to transfer legacy permissions from ContentLibraryPermission to the new Casbin-based authorization model.
+
 0.17.1 - 2025-11-14
 ********************
 
diff --git a/openedx_authz/__init__.py b/openedx_authz/__init__.py
@@ -4,6 +4,6 @@
 
 import os
 
-__version__ = "0.17.1"
+__version__ = "0.18.0"
 
 ROOT_DIRECTORY = os.path.dirname(os.path.abspath(__file__))
diff --git a/openedx_authz/engine/utils.py b/openedx_authz/engine/utils.py
@@ -8,6 +8,9 @@
 
 from casbin import Enforcer
 
+from openedx_authz.api.users import assign_role_to_user_in_scope, batch_assign_role_to_users_in_scope
+from openedx_authz.constants.roles import LIBRARY_ADMIN, LIBRARY_AUTHOR, LIBRARY_USER
+
 logger = logging.getLogger(__name__)
 
 GROUPING_POLICY_PTYPES = ["g", "g2", "g3", "g4", "g5", "g6"]
@@ -69,3 +72,82 @@ def migrate_policy_between_enforcers(
     except Exception as e:
         logger.error(f"Error loading policies from file: {e}")
         raise
+
+
+def migrate_legacy_permissions(ContentLibraryPermission):
+    """
+    Migrate legacy permission data to the new Casbin-based authorization model.
+    This function reads legacy permissions from the ContentLibraryPermission model
+    and assigns equivalent roles in the new authorization system.
+
+    The old Library permissions are stored in the ContentLibraryPermission model, it consists of the following columns:
+
+    - library: FK to ContentLibrary
+    - user: optional FK to User
+    - group: optional FK to Group
+    - access_level: 'admin' | 'author' | 'read'
+
+    In the new Authz model, this would roughly translate to:
+
+    - library: scope
+    - user: subject
+    - access_level: role
+
+    Now, we don't have an equivalent concept to "Group", for this we will go through the users in the group and assign
+    roles independently.
+
+    param ContentLibraryPermission: The ContentLibraryPermission model to use.
+    """
+
+    legacy_permissions = ContentLibraryPermission.objects.select_related(
+        "library", "library__org", "user", "group"
+    ).all()
+
+    # List to keep track of any permissions that could not be migrated
+    permissions_with_errors = []
+
+    for permission in legacy_permissions:
+        # Migrate the permission to the new model
+
+        # Derive equivalent role based on access level
+        access_level_to_role = {
+            "admin": LIBRARY_ADMIN,
+            "author": LIBRARY_AUTHOR,
+            "read": LIBRARY_USER,
+        }
+
+        role = access_level_to_role.get(permission.access_level)
+        if role is None:
+            # This should not happen as there are no more access_levels defined
+            # in ContentLibraryPermission, log and skip
+            logger.error(f"Unknown access level: {permission.access_level} for User: {permission.user}")
+            permissions_with_errors.append(permission)
+            continue
+
+        # Generating scope based on library identifier
+        scope = f"lib:{permission.library.org.name}:{permission.library.slug}"
+
+        if permission.group:
+            # Permission applied to a group
+            users = [user.username for user in permission.group.user_set.all()]
+            logger.info(
+                f"Migrating permissions for Users: {users} in Group: {permission.group.name} "
+                f"to Role: {role.external_key} in Scope: {scope}"
+            )
+            batch_assign_role_to_users_in_scope(
+                users=users, role_external_key=role.external_key, scope_external_key=scope
+            )
+        else:
+            # Permission applied to individual user
+            logger.info(
+                f"Migrating permission for User: {permission.user.username} "
+                f"to Role: {role.external_key} in Scope: {scope}"
+            )
+
+            assign_role_to_user_in_scope(
+                user_external_key=permission.user.username,
+                role_external_key=role.external_key,
+                scope_external_key=scope,
+            )
+
+    return permissions_with_errors
diff --git a/openedx_authz/migrations/0005_migrate_legacy_permissions.py b/openedx_authz/migrations/0005_migrate_legacy_permissions.py
@@ -0,0 +1,61 @@
+# Generated by Django 5.2.7 on 2025-11-03 20:39
+
+import logging
+
+from django.db import migrations
+
+from openedx_authz.engine.utils import migrate_legacy_permissions
+
+logger = logging.getLogger(__name__)
+
+
+def _log_migration_errors(permissions_with_errors: list) -> None:
+    """
+    Log the permissions that could not be migrated during the migration process.
+    Args:
+        permissions_with_errors (list): List of ContentLibraryPermission instances that failed to migrate.
+    """
+    logger.error(
+        f"Migration completed with errors for {len(permissions_with_errors)} permissions.\n"
+        "The following permissions could not be migrated:"
+    )
+    for permission in permissions_with_errors:
+        logger.error(
+            "Access level: %s, %sLibrary: %s",
+            permission.access_level,
+            f"User: {permission.user.username}, " if permission.user else f"Group: {permission.group.name}, ",
+            permission.library.slug,
+        )
+
+
+def apply_migrate_legacy_permissions(apps, schema_editor):
+    """
+    Wrapper to run the migration using the historical version of the ContentLibraryPermission model.
+    """
+    # ContentLibraryPermission model from the content_libraries app, here is where the legacy permissions are stored
+    try:
+        ContentLibraryPermission = apps.get_model("content_libraries", "ContentLibraryPermission")
+    except LookupError:
+        # Don't run the migration where the content_libraries app is not installed, like during development.
+        logger.warning("ContentLibraryPermission model not found. Skipping migration.")
+        return
+
+    permissions_with_errors = migrate_legacy_permissions(ContentLibraryPermission)
+
+    if permissions_with_errors:
+        _log_migration_errors(permissions_with_errors)
+
+
+class Migration(migrations.Migration):
+    """
+    Migration to transfer legacy permissions from ContentLibraryPermission
+    to the new Casbin-based authorization model.
+    """
+
+    dependencies = [
+        ("openedx_authz", "0004_contentlibraryscope"),
+    ]
+
+    operations = [
+        migrations.RunPython(apply_migrate_legacy_permissions),
+    ]
diff --git a/openedx_authz/tests/stubs/models.py b/openedx_authz/tests/stubs/models.py
@@ -4,10 +4,25 @@
 referenced in FK relationships without requiring the full application context.
 """
 
+from django.conf import settings
+from django.contrib.auth.models import Group
 from django.db import models
 from opaque_keys.edx.locator import LibraryLocatorV2
 
 
+class Organization(models.Model):
+    """Stub model representing an organization for testing purposes.
+
+    .. no_pii:
+    """
+
+    name = models.CharField(max_length=255)
+    short_name = models.CharField(max_length=100)
+
+    def __str__(self):
+        return str(self.name)
+
+
 class ContentLibraryManager(models.Manager):
     """Manager for ContentLibrary model with helper methods."""
 
@@ -38,9 +53,37 @@ class ContentLibrary(models.Model):
 
     locator = models.CharField(max_length=255, unique=True, db_index=True)
     title = models.CharField(max_length=255, blank=True, null=True)
+    slug = models.SlugField(allow_unicode=True)
+    org = models.ForeignKey(Organization, on_delete=models.PROTECT, null=True)
     created_at = models.DateTimeField(auto_now_add=True)
 
     objects = ContentLibraryManager()
 
     def __str__(self):
-        return self.locator
+        return str(self.locator)
+
+
+# Legacy permission models for testing purposes
+class ContentLibraryPermission(models.Model):
+    """Stub model representing legacy content library permissions for testing purposes.
+
+    .. no_pii:
+    """
+
+    ADMIN_LEVEL = "admin"
+    AUTHOR_LEVEL = "author"
+    READ_LEVEL = "read"
+    ACCESS_LEVEL_CHOICES = (
+        (ADMIN_LEVEL, "Administer users and author content"),
+        (AUTHOR_LEVEL, "Author content"),
+        (READ_LEVEL, "Read-only"),
+    )
+
+    library = models.ForeignKey(ContentLibrary, on_delete=models.CASCADE)
+    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, null=True, blank=True)
+    group = models.ForeignKey(Group, on_delete=models.CASCADE, null=True, blank=True)
+    access_level = models.CharField(max_length=30, choices=ACCESS_LEVEL_CHOICES)
+
+    def __str__(self):
+        who = self.user.username if self.user else self.group.name
+        return f"ContentLibraryPermission ({self.access_level} for {who})"
diff --git a/openedx_authz/tests/test_migrations.py b/openedx_authz/tests/test_migrations.py
@@ -0,0 +1,147 @@
+"""Unit Tests for openedx_authz migrations."""
+
+from django.contrib.auth import get_user_model
+from django.contrib.auth.models import Group
+from django.test import TestCase
+
+from openedx_authz.api.users import batch_unassign_role_from_users, get_user_role_assignments_in_scope
+from openedx_authz.constants.roles import LIBRARY_ADMIN, LIBRARY_USER
+from openedx_authz.engine.enforcer import AuthzEnforcer
+from openedx_authz.engine.utils import migrate_legacy_permissions
+from openedx_authz.tests.stubs.models import ContentLibrary, ContentLibraryPermission, Organization
+
+User = get_user_model()
+
+# Specify a unique prefix to avoid collisions with existing data
+OBJECT_PREFIX = "tmlp_"
+
+org_name = f"{OBJECT_PREFIX}org"
+lib_name = f"{OBJECT_PREFIX}library"
+group_name = f"{OBJECT_PREFIX}test_group"
+user_names = [f"{OBJECT_PREFIX}user{i}" for i in range(3)]
+group_user_names = [f"{OBJECT_PREFIX}guser{i}" for i in range(3)]
+error_user_name = f"{OBJECT_PREFIX}error_user"
+error_group_name = f"{OBJECT_PREFIX}error_group"
+empty_group_name = f"{OBJECT_PREFIX}empty_group"
+
+
+class TestLegacyPermissionsMigration(TestCase):
+    """Test cases for migrating legacy permissions."""
+
+    def setUp(self):
+        """
+        Set up test data:
+
+        What this does:
+        1. Creates an Org and a ContentLibrary
+        2. Create Users and Groups
+        3. Assign legacy permissions using ContentLibraryPermission
+        4. Create invalid permissions for user and group
+        """
+        # Create ContentLibrary
+
+        org = Organization.objects.create(name=org_name, short_name=org_name)
+        library = ContentLibrary.objects.create(org=org, slug=lib_name)
+
+        # Create Users and Groups
+        users = [
+            User.objects.create_user(username=user_name, email=f"{user_name}@example.com") for user_name in user_names
+        ]
+
+        group_users = [
+            User.objects.create_user(username=user_name, email=f"{user_name}@example.com")
+            for user_name in group_user_names
+        ]
+        group = Group.objects.create(name=group_name)
+        group.user_set.set(group_users)
+
+        error_user = User.objects.create_user(username=error_user_name, email=f"{error_user_name}@example.com")
+        error_group = Group.objects.create(name=error_group_name)
+        error_group.user_set.set([error_user])
+
+        empty_group = Group.objects.create(name=empty_group_name)
+
+        # Assign legacy permissions for users and group
+        for user in users:
+            ContentLibraryPermission.objects.create(
+                user=user,
+                library=library,
+                access_level=ContentLibraryPermission.ADMIN_LEVEL,
+            )
+
+        ContentLibraryPermission.objects.create(
+            group=group,
+            library=library,
+            access_level=ContentLibraryPermission.READ_LEVEL,
+        )
+
+        # Create invalid permissions for testing error logging
+        ContentLibraryPermission.objects.create(
+            user=error_user,
+            library=library,
+            access_level="invalid",
+        )
+        ContentLibraryPermission.objects.create(
+            group=error_group,
+            library=library,
+            access_level="invalid",
+        )
+
+        # Edge case: empty group with no users
+        ContentLibraryPermission.objects.create(
+            group=empty_group,
+            library=library,
+            access_level=ContentLibraryPermission.READ_LEVEL,
+        )
+
+    def tearDown(self):
+        """
+        Clean up test data created for the migration test.
+        """
+        super().tearDown()
+
+        AuthzEnforcer.get_enforcer().load_policy()
+        batch_unassign_role_from_users(
+            users=user_names,
+            role_external_key=LIBRARY_ADMIN.external_key,
+            scope_external_key=f"lib:{org_name}:{lib_name}",
+        )
+        batch_unassign_role_from_users(
+            users=group_user_names,
+            role_external_key=LIBRARY_USER.external_key,
+            scope_external_key=f"lib:{org_name}:{lib_name}",
+        )
+
+        ContentLibrary.objects.filter(slug=lib_name).delete()
+        Organization.objects.filter(name=org_name).delete()
+        Group.objects.filter(name=group_name).delete()
+        Group.objects.filter(name=error_group_name).delete()
+        Group.objects.filter(name=empty_group_name).delete()
+        for user_name in user_names + group_user_names + [error_user_name]:
+            User.objects.filter(username=user_name).delete()
+
+    def test_migration(self):
+        """Test the migration of legacy permissions.
+        1. Rus the migration to migrate legacy permissions.
+        2. Check that each user has the expected role in the new model.
+        3. Check that the group users have the expected role in the new model.
+        4. Check that invalid permissions were identified correctly as errors.
+        """
+
+        permissions_with_errors = migrate_legacy_permissions(ContentLibraryPermission)
+
+        AuthzEnforcer.get_enforcer().load_policy()
+        for user_name in user_names:
+            assignments = get_user_role_assignments_in_scope(
+                user_external_key=user_name, scope_external_key=f"lib:{org_name}:{lib_name}"
+            )
+            self.assertEqual(len(assignments), 1)
+            self.assertEqual(assignments[0].roles[0], LIBRARY_ADMIN)
+        for group_user_name in group_user_names:
+            assignments = get_user_role_assignments_in_scope(
+                user_external_key=group_user_name, scope_external_key=f"lib:{org_name}:{lib_name}"
+            )
+            self.assertEqual(len(assignments), 1)
+            self.assertEqual(assignments[0].roles[0], LIBRARY_USER)
+
+        self.assertEqual(len(permissions_with_errors), 2)
