stream: Do not use hardcoded default values for group settings.

We were using admins group as a hardcoded value for the default of
`can_remove_subscribers_group`, now we use a function to get the value
of the default group.

zerver/lib/bulk_create.py

@@ -6,7 +6,7 @@ from django.utils.timezone import now as timezone_now
 
 from zerver.lib.create_user import create_user_profile, get_display_email_address
 from zerver.lib.initial_password import initial_password
-from zerver.lib.streams import render_stream_description
+from zerver.lib.streams import get_default_group_setting_values, render_stream_description
 from zerver.models import (
     NamedUserGroup,
     Realm,
@@ -200,9 +200,6 @@ def bulk_create_streams(realm: Realm, stream_dict: dict[str, dict[str, Any]]) ->
     existing_streams = {
         name.lower() for name in Stream.objects.filter(realm=realm).values_list("name", flat=True)
     }
-    administrators_user_group = NamedUserGroup.objects.get(
-        name=SystemGroups.ADMINISTRATORS, is_system_group=True, realm=realm
-    )
     streams_to_create: list[Stream] = []
     for name, options in stream_dict.items():
         if "history_public_to_subscribers" not in options:
@@ -223,8 +220,8 @@ def bulk_create_streams(realm: Realm, stream_dict: dict[str, dict[str, Any]]) ->
                     history_public_to_subscribers=options["history_public_to_subscribers"],
                     is_web_public=options.get("is_web_public", False),
                     is_in_zephyr_realm=realm.is_zephyr_mirror_realm,
-                    can_remove_subscribers_group=administrators_user_group,
                     creator=options.get("creator", None),
+                    **get_default_group_setting_values(realm),
                 ),
             )
     # Sort streams by name before creating them so that we can have a

zerver/lib/import_realm.py

@@ -46,7 +46,11 @@ from zerver.lib.partial import partial
 from zerver.lib.push_notifications import sends_notifications_directly
 from zerver.lib.remote_server import maybe_enqueue_audit_log_upload
 from zerver.lib.server_initialization import create_internal_realm, server_initialized
-from zerver.lib.streams import render_stream_description, update_stream_active_status_for_realm
+from zerver.lib.streams import (
+    get_stream_permission_default_group,
+    render_stream_description,
+    update_stream_active_status_for_realm,
+)
 from zerver.lib.thumbnail import THUMBNAIL_ACCEPT_IMAGE_TYPES, BadImageError, maybe_thumbnail
 from zerver.lib.timestamp import datetime_to_timestamp
 from zerver.lib.upload import ensure_avatar_image, sanitize_name, upload_backend, upload_emoji_image
@@ -243,13 +247,11 @@ def fix_upload_links(data: TableData, message_table: TableName) -> None:
                     )
 
 
-def fix_streams_can_remove_subscribers_group_column(data: TableData, realm: Realm) -> None:
+def fix_stream_permission_group_settings(data: TableData, realm: Realm) -> None:
     table = get_db_table(Stream)
-    admins_group = NamedUserGroup.objects.get(
-        name=SystemGroups.ADMINISTRATORS, realm=realm, is_system_group=True
-    )
     for stream in data[table]:
-        stream["can_remove_subscribers_group"] = admins_group
+        for setting_name in Stream.stream_permission_group_settings:
+            stream[setting_name] = get_stream_permission_default_group(setting_name, realm)
 
 
 def create_subscription_events(data: TableData, realm_id: int) -> None:
@@ -1289,13 +1291,12 @@ def do_import_realm(import_dir: Path, subdomain: str, processes: int = 1) -> Rea
 
         if role_system_groups_dict is not None:
             # Because the system user groups are missing, we manually set up
-            # the defaults for can_remove_subscribers_group for all the
+            # the defaults for stream permission settings for all the
             # streams.
-            fix_streams_can_remove_subscribers_group_column(data, realm)
+            fix_stream_permission_group_settings(data, realm)
         else:
-            re_map_foreign_keys(
-                data, "zerver_stream", "can_remove_subscribers_group", related_table="usergroup"
-            )
+            for setting_name in Stream.stream_permission_group_settings:
+                re_map_foreign_keys(data, "zerver_stream", setting_name, related_table="usergroup")
         # Handle rendering of stream descriptions for import from non-Zulip
         for stream in data["zerver_stream"]:
             stream["rendered_description"] = render_stream_description(stream["description"], realm)

zerver/lib/streams.py

@@ -41,7 +41,6 @@ from zerver.models import (
     UserGroupMembership,
     UserProfile,
 )
-from zerver.models.groups import SystemGroups
 from zerver.models.realm_audit_logs import AuditLogEventType
 from zerver.models.streams import (
     bulk_get_streams,
@@ -140,6 +139,25 @@ def send_stream_creation_event(
     send_event_on_commit(realm, event, user_ids)
 
 
+def get_stream_permission_default_group(setting_name: str, realm: Realm) -> UserGroup:
+    setting_default_name = Stream.stream_permission_group_settings[setting_name].default_group_name
+    return NamedUserGroup.objects.get(
+        name=setting_default_name,
+        realm=realm,
+        is_system_group=True,
+    )
+
+
+def get_default_group_setting_values(realm: Realm) -> dict[str, UserGroup]:
+    group_setting_values = {}
+    for setting_name in Stream.stream_permission_group_settings:
+        group_setting_values[setting_name] = get_stream_permission_default_group(
+            setting_name, realm
+        )
+
+    return group_setting_values
+
+
 @transaction.atomic(savepoint=False)
 def create_stream_if_needed(
     realm: Realm,
@@ -159,14 +177,21 @@ def create_stream_if_needed(
         realm, invite_only, history_public_to_subscribers
     )
 
-    if can_remove_subscribers_group is None:
-        can_remove_subscribers_group = NamedUserGroup.objects.get(
-            name=SystemGroups.ADMINISTRATORS, is_system_group=True, realm=realm
-        )
+    group_setting_values = {}
+    request_settings_dict = locals()
+    for setting_name in Stream.stream_permission_group_settings:
+        if setting_name not in request_settings_dict:  # nocoverage
+            continue
+
+        if request_settings_dict[setting_name] is None:
+            group_setting_values[setting_name] = get_stream_permission_default_group(
+                setting_name, realm
+            )
+        else:
+            group_setting_values[setting_name] = request_settings_dict[setting_name]
 
     stream_name = stream_name.strip()
 
-    assert can_remove_subscribers_group is not None
     (stream, created) = Stream.objects.get_or_create(
         realm=realm,
         name__iexact=stream_name,
@@ -180,7 +205,7 @@ def create_stream_if_needed(
             history_public_to_subscribers=history_public_to_subscribers,
             is_in_zephyr_realm=realm.is_zephyr_mirror_realm,
             message_retention_days=message_retention_days,
-            can_remove_subscribers_group=can_remove_subscribers_group,
+            **group_setting_values,
         ),
     )
 

zerver/lib/test_classes.py

@@ -60,6 +60,7 @@ from zerver.lib.soft_deactivation import do_soft_deactivate_users
 from zerver.lib.stream_subscription import get_subscribed_stream_ids_for_user
 from zerver.lib.streams import (
     create_stream_if_needed,
+    get_default_group_setting_values,
     get_default_value_for_history_public_to_subscribers,
 )
 from zerver.lib.subscription_info import gather_subscriptions
@@ -103,7 +104,6 @@ from zerver.models import (
     UserProfile,
     UserStatus,
 )
-from zerver.models.groups import SystemGroups
 from zerver.models.realms import clear_supported_auth_backends_cache, get_realm
 from zerver.models.streams import get_realm_stream, get_stream
 from zerver.models.users import get_system_bot, get_user, get_user_by_delivery_email
@@ -1377,9 +1377,6 @@ Output:
         history_public_to_subscribers = get_default_value_for_history_public_to_subscribers(
             realm, invite_only, history_public_to_subscribers
         )
-        administrators_user_group = NamedUserGroup.objects.get(
-            name=SystemGroups.ADMINISTRATORS, realm=realm, is_system_group=True
-        )
 
         try:
             stream = Stream.objects.create(
@@ -1388,7 +1385,7 @@ Output:
                 invite_only=invite_only,
                 is_web_public=is_web_public,
                 history_public_to_subscribers=history_public_to_subscribers,
-                can_remove_subscribers_group=administrators_user_group,
+                **get_default_group_setting_values(realm),
             )
         except IntegrityError:  # nocoverage -- this is for bugs in the tests
             raise Exception(