Update generate_course_blocks management command to enqueue tasks

openedx/core/djangoapps/content/block_structure/tasks.py

@@ -29,17 +29,37 @@ def update_course_in_cache(course_id):
     """
     Updates the course blocks (in the database) for the specified course.
     """
+    _call_and_retry_if_needed(course_id, api.update_course_in_cache, update_course_in_cache)
+
+
+@task(
+    default_retry_delay=settings.BLOCK_STRUCTURES_SETTINGS['BLOCK_STRUCTURES_TASK_DEFAULT_RETRY_DELAY'],
+    max_retries=settings.BLOCK_STRUCTURES_SETTINGS['BLOCK_STRUCTURES_TASK_MAX_RETRIES'],
+)
+def get_course_in_cache(course_id):
+    """
+    Gets the course blocks for the specified course, updating the cache if needed.
+    """
+    _call_and_retry_if_needed(course_id, api.get_course_in_cache, get_course_in_cache)
+
+
+def _call_and_retry_if_needed(course_id, api_method, task_method):
+    """
+    Calls the given api_method with the given course_id, retrying task_method upon failure.
+    """
     try:
         course_key = CourseKey.from_string(course_id)
-        api.update_course_in_cache(course_key)
+        api_method(course_key)
     except NO_RETRY_TASKS as exc:
         # Known unrecoverable errors
         raise
     except RETRY_TASKS as exc:
-        log.exception("update_course_in_cache encounted expected error, retrying.")
-        raise update_course_in_cache.retry(args=[course_id], exc=exc)
+        log.exception("%s encountered expected error, retrying.", task_method.__name__)
+        raise task_method.retry(args=[course_id], exc=exc)
     except Exception as exc:   # pylint: disable=broad-except
-        log.exception("update_course_in_cache encounted unknown error. Retry #{}".format(
-            update_course_in_cache.request.retries,
-        ))
-        raise update_course_in_cache.retry(args=[course_id], exc=exc)
+        log.exception(
+            "%s encountered unknown error. Retry #%d",
+            task_method.__name__,
+            task_method.request.retries,
+        )
+        raise task_method.retry(args=[course_id], exc=exc)

openedx/core/lib/command_utils.py

@@ -0,0 +1,48 @@
+"""
+Useful utilities for management commands.
+"""
+
+from django.core.management.base import CommandError
+
+from opaque_keys import InvalidKeyError
+from opaque_keys.edx.keys import CourseKey
+
+
+def get_mutually_exclusive_required_option(options, option_1, option_2):
+    """
+    Validates that exactly one of the 2 given options is specified.
+    Returns the name of the found option.
+    """
+    validate_mutually_exclusive_option(options, option_1, option_2)
+
+    if not options.get(option_1) and not options.get(option_2):
+        raise CommandError('Either --{} or --{} must be specified.'.format(option_1, option_2))
+
+    return option_1 if options.get(option_1) else option_2
+
+
+def validate_mutually_exclusive_option(options, option_1, option_2):
+    """
+    Validates that both of the 2 given options are not specified.
+    """
+    if options.get(option_1) and options.get(option_2):
+        raise CommandError('Both --{} and --{} cannot be specified.'.format(option_1, option_2))
+
+
+def validate_dependent_option(options, dependent_option, depending_on_option):
+    """
+    Validates that option_1 is specified if dependent_option is specified.
+    """
+    if options.get(dependent_option) and not options.get(depending_on_option):
+        raise CommandError('Option --{} requires option --{}.'.format(dependent_option, depending_on_option))
+
+
+def parse_course_keys(course_key_strings):
+    """
+    Parses and returns a list of CourseKey objects from the given
+    list of course key strings.
+    """
+    try:
+        return [CourseKey.from_string(course_key_string) for course_key_string in course_key_strings]
+    except InvalidKeyError as error:
+        raise CommandError('Invalid key specified: {}'.format(error.message))