Add generic tworker. (#4418)

This tworker will only run preprocess and postprocess. It can do this
regardless of the platform of the task.

Also, get rid of some kludges used to test utasks in oss-fuzz.
b/380104573

docker/build.sh

@@ -27,6 +27,7 @@ IMAGES=(
   gcr.io/clusterfuzz-images/oss-fuzz/worker
   gcr.io/clusterfuzz-images/ci
   gcr.io/clusterfuzz-images/utask-main-scheduler
+  gcr.io/clusterfuzz-images/tworker
   gcr.io/clusterfuzz-images/fuchsia
 )
 

docker/tworker/Dockerfile

@@ -0,0 +1,17 @@
+# Copyright 2024 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+FROM gcr.io/clusterfuzz-images/base
+
+# Worker that only reads from queues, preprocesses and postprocesses.
+ENV TWORKER=1

src/clusterfuzz/_internal/base/tasks/__init__.py

@@ -83,6 +83,7 @@
 
 POSTPROCESS_QUEUE = 'postprocess'
 UTASK_MAINS_QUEUE = 'utask_main'
+PREPROCESS_QUEUE = 'preprocess'
 
 # See https://github.com/google/clusterfuzz/issues/3347 for usage
 SUBQUEUE_IDENTIFIER = ':'
@@ -281,8 +282,7 @@ def is_done_collecting_messages():
 def get_postprocess_task():
   """Gets a postprocess task if one exists."""
   # This should only be run on non-preemptible bots.
-  if not (task_utils.is_remotely_executing_utasks() or
-          task_utils.get_opted_in_tasks()):
+  if not task_utils.is_remotely_executing_utasks():
     return None
   # Postprocess is platform-agnostic, so we run all such tasks on our
   # most generic and plentiful bots only. In other words, we avoid
@@ -304,9 +304,29 @@ def allow_all_tasks():
   return not environment.get_value('PREEMPTIBLE')
 
 
+def get_preprocess_task():
+  pubsub_puller = PubSubPuller(PREPROCESS_QUEUE)
+  messages = pubsub_puller.get_messages(max_messages=1)
+  if not messages:
+    return None
+  task = get_task_from_message(messages[0])
+  if task:
+    logs.info('Pulled from preprocess queue.')
+  return task
+
+
+def tworker_get_task():
+  assert environment.is_tworker()
+  task = get_postprocess_task()
+  if task:
+    return task
+
+  return get_preprocess_task()
+
+
 def get_task():
-  """Returns an ordinary (non-postprocess, non-utask_main) task that is pulled
-  from a ClusterFuzz task queue."""
+  """Returns an ordinary (non-utask_main) task that is pulled from a ClusterFuzz
+  task queue."""
   task = get_command_override()
   if task:
     return task
@@ -319,6 +339,7 @@ def get_task():
     task = get_postprocess_task()
     if task:
       return task
+
     # Check the high-end jobs queue for bots with multiplier greater than 1.
     thread_multiplier = environment.get_value('THREAD_MULTIPLIER')
     if thread_multiplier and thread_multiplier > 1:
@@ -368,8 +389,7 @@ def __init__(self,
                eta=None,
                is_command_override=False,
                high_end=False,
-               extra_info=None,
-               is_from_queue=False):
+               extra_info=None):
     self.command = command
     self.argument = argument
     self.job = job
@@ -378,16 +398,6 @@ def __init__(self,
     self.high_end = high_end
     self.extra_info = extra_info
 
-    # is_from_queue is a temporary hack to keep track of which fuzz tasks came
-    # from the queue. Previously all fuzz tasks were picked by the bot when
-    # there was nothing on the queue. With the rearchitecture, we want fuzz
-    # tasks that were put on the queue by the schedule_fuzz cron job to be
-    # executed on batch. is_from_queue is used to do this.
-    # TODO(b/378684001): This code is very ugly, get rid of it when no more
-    # fuzz tasks are executed on the bots themselves (i.e. when the rearch
-    # is complete).
-    self.is_from_queue = is_from_queue
-
   def __repr__(self):
     return f'Task: {self.command} {self.argument} {self.job}'
 
@@ -428,13 +438,11 @@ def lease(self):
 class PubSubTask(Task):
   """A Pub/Sub task."""
 
-  def __init__(self, pubsub_message, is_from_queue=False):
+  def __init__(self, pubsub_message):
     self._pubsub_message = pubsub_message
     super().__init__(
-        self.attribute('command'),
-        self.attribute('argument'),
-        self.attribute('job'),
-        is_from_queue=is_from_queue)
+        self.attribute('command'), self.attribute('argument'),
+        self.attribute('job'))
 
     self.extra_info = {
         key: value
@@ -540,7 +548,7 @@ def initialize_task(message) -> PubSubTask:
   """Creates a task from |messages|."""
 
   if message.attributes.get('eventType') != 'OBJECT_FINALIZE':
-    return PubSubTask(message, is_from_queue=True)
+    return PubSubTask(message)
 
   # Handle postprocess task.
   # The GCS API for pub/sub notifications uses the data field unlike
@@ -549,7 +557,7 @@ def initialize_task(message) -> PubSubTask:
   name = data['name']
   bucket = data['bucket']
   output_url_argument = storage.get_cloud_storage_file_path(bucket, name)
-  return PostprocessPubSubTask(output_url_argument, message, is_from_queue=True)
+  return PostprocessPubSubTask(output_url_argument, message)
 
 
 class PostprocessPubSubTask(PubSubTask):
@@ -558,21 +566,14 @@ class PostprocessPubSubTask(PubSubTask):
   def __init__(self,
                output_url_argument,
                pubsub_message,
-               is_command_override=False,
-               is_from_queue=False):
+               is_command_override=False):
     command = 'postprocess'
     job_type = 'none'
     eta = None
     high_end = False
     grandparent_class = super(PubSubTask, self)
-    grandparent_class.__init__(
-        command,
-        output_url_argument,
-        job_type,
-        eta,
-        is_command_override,
-        high_end,
-        is_from_queue=is_from_queue)
+    grandparent_class.__init__(command, output_url_argument, job_type, eta,
+                               is_command_override, high_end)
     self._pubsub_message = pubsub_message
 
 

src/clusterfuzz/_internal/base/tasks/task_utils.py

@@ -15,7 +15,6 @@
 any other module in tasks to prevent circular imports and issues with
 appengine."""
 
-from clusterfuzz._internal.config import local_config
 from clusterfuzz._internal.system import environment
 
 
@@ -26,25 +25,12 @@ def get_command_from_module(full_module_name: str) -> str:
   return module_name[:-len('_task')]
 
 
-def is_remotely_executing_utasks(task=None) -> bool:
+def is_remotely_executing_utasks() -> bool:
   """Returns True if the utask_main portions of utasks are being remotely
   executed on Google cloud batch."""
-  if bool(environment.is_production() and
-          environment.get_value('REMOTE_UTASK_EXECUTION')):
-    return True
-  if task is None:
-    return False
-  return bool(is_task_opted_into_uworker_execution(task))
-
-
-def get_opted_in_tasks():
-  return local_config.ProjectConfig().get('uworker_tasks', [])
-
-
-def is_task_opted_into_uworker_execution(task: str) -> bool:
-  # TODO(metzman): Remove this after OSS-Fuzz and Chrome are at parity.
-  uworker_tasks = get_opted_in_tasks()
-  return task in uworker_tasks
+  # TODO(metzman): REMOTE_UTASK_EXECUTION should be a config not an env var.
+  return (environment.is_production() and
+          environment.get_value('REMOTE_UTASK_EXECUTION'))
 
 
 class UworkerMsgParseError(RuntimeError):

src/clusterfuzz/_internal/bot/tasks/commands.py

@@ -190,11 +190,25 @@ def start_web_server_if_needed():
     logs.error('Failed to start web server, skipping.')
 
 
+def get_command_object(task_name):
+  """Returns the command object that execute can be called on."""
+  task = COMMAND_MAP.get(task_name)
+  if not environment.is_tworker():
+    return task
+
+  if isinstance(task, task_types.TrustedTask):
+    # We don't need to execute this remotely.
+    return task
+
+  # Force remote execution.
+  return task_types.UTask(task_name)
+
+
 def run_command(task_name, task_argument, job_name, uworker_env):
   """Runs the command."""
-  task = COMMAND_MAP.get(task_name)
+  task = get_command_object(task_name)
   if not task:
-    logs.error("Unknown command '%s'" % task_name)
+    logs.error(f'Unknown command "{task_name}"')
     return None
 
   # If applicable, ensure this is the only instance of the task running.
@@ -253,10 +267,8 @@ def process_command(task):
     logs.error('Empty task received.')
     return None
 
-  # TODO(b/378684001): Remove is_from_queue kludge.
   return process_command_impl(task.command, task.argument, task.job,
-                              task.high_end, task.is_command_override,
-                              task.is_from_queue)
+                              task.high_end, task.is_command_override)
 
 
 def _get_task_id(task_name, task_argument, job_name):
@@ -267,13 +279,12 @@ def _get_task_id(task_name, task_argument, job_name):
 # TODO(mbarbella): Rewrite this function to avoid nesting issues.
 @set_task_payload
 def process_command_impl(task_name, task_argument, job_name, high_end,
-                         is_command_override, is_from_queue):
+                         is_command_override):
   """Implementation of process_command."""
   uworker_env = None
   environment.set_value('TASK_NAME', task_name)
   environment.set_value('TASK_ARGUMENT', task_argument)
   environment.set_value('JOB_NAME', job_name)
-  environment.set_value('IS_FROM_QUEUE', is_from_queue)
   if task_name in {'uworker_main', 'postprocess'}:
     # We want the id of the task we are processing, not "uworker_main", or
     # "postprocess".
@@ -456,5 +467,3 @@ def process_command_impl(task_name, task_argument, job_name, high_end,
     cleanup_task_state()
     if 'CF_TASK_ID' in os.environ:
       del os.environ['CF_TASK_ID']
-    if 'IS_FROM_QUEUE' in os.environ:
-      del os.environ['IS_FROM_QUEUE']

src/clusterfuzz/_internal/bot/tasks/task_types.py

@@ -46,6 +46,7 @@ class TrustedTask(BaseTask):
   def execute(self, task_argument, job_type, uworker_env):
     # Simple tasks can just use the environment they don't need the uworker env.
     del uworker_env
+    assert not environment.is_tworker()
     self.module.execute_task(task_argument, job_type)
 
 
@@ -58,6 +59,8 @@ def execute(self, task_argument, job_type, uworker_env):
     raise NotImplementedError('Child class must implement.')
 
   def execute_locally(self, task_argument, job_type, uworker_env):
+    """Executes the utask locally (on this machine, not on batch)."""
+    assert not environment.is_tworker()
     uworker_input = utasks.tworker_preprocess_no_io(self.module, task_argument,
                                                     job_type, uworker_env)
     if uworker_input is None:
@@ -119,7 +122,7 @@ class UTask(BaseUTask):
 
   @staticmethod
   def is_execution_remote(command=None):
-    return task_utils.is_remotely_executing_utasks(command)
+    return task_utils.is_remotely_executing_utasks()
 
   def execute(self, task_argument, job_type, uworker_env):
     """Executes a utask."""
@@ -156,19 +159,6 @@ def preprocess(self, task_argument, job_type, uworker_env):
     return download_url
 
 
-# TODO(b/378684001): Remove this, it's needed for testing but is otherwise a bad
-# design.
-class UTaskMostlyLocalExecutor(UTask):
-
-  @staticmethod
-  def is_execution_remote(command=None):
-    del command
-    if environment.get_value('IS_FROM_QUEUE'):
-      logs.info('IS FROM QUEUE')
-      return True
-    return False
-
-
 class PostprocessTask(BaseTask):
   """Represents postprocessing of an untrusted task."""
 
@@ -211,7 +201,7 @@ def execute(self, task_argument, job_type, uworker_env):
     'analyze': UTask,
     'blame': TrustedTask,
     'corpus_pruning': UTask,
-    'fuzz': UTaskMostlyLocalExecutor,
+    'fuzz': UTaskLocalExecutor,
     'impact': TrustedTask,
     'minimize': UTask,
     'progression': UTask,

src/clusterfuzz/_internal/cron/schedule_fuzz.py

@@ -20,7 +20,6 @@
 
 from googleapiclient import discovery
 
-from clusterfuzz._internal.base import concurrency
 from clusterfuzz._internal.base import tasks
 from clusterfuzz._internal.base import utils
 from clusterfuzz._internal.config import local_config
@@ -167,14 +166,12 @@ def get_fuzz_tasks(self) -> Dict[str, tasks.Task]:
 
     choices = random.choices(
         fuzz_task_candidates, weights=weights, k=num_instances)
-    queues_to_tasks = collections.defaultdict(list)
-    for fuzz_task_candidate in choices:
-      queue_tasks = queues_to_tasks[fuzz_task_candidate.queue]
-
-      task = tasks.Task('fuzz', fuzz_task_candidate.fuzzer,
-                        fuzz_task_candidate.job)
-      queue_tasks.append(task)
-    return queues_to_tasks
+    fuzz_tasks = [
+        tasks.Task('fuzz', fuzz_task_candidate.fuzzer, fuzz_task_candidate.job)
+        for fuzz_task_candidate in choices
+    ]
+    # TODO(metzman): Remove the queue stuff if it's uneeded for Chrome.
+    return fuzz_tasks
 
 
 def get_fuzz_tasks(available_cpus: int) -> [tasks.Task]:
@@ -210,10 +207,8 @@ def schedule_fuzz_tasks() -> bool:
     logs.error('No fuzz tasks found to schedule.')
     return False
 
-  # TODO(b/378684001): Change this to using one queue when oss-fuzz's untrusted
-  # worker model is deleted.
-  with concurrency.make_pool() as pool:
-    list(pool.map(bulk_add, fuzz_tasks.items()))
+  logs.info(f'Adding {fuzz_tasks} to preprocess queue.')
+  tasks.bulk_add_tasks(fuzz_tasks, queue=tasks.PREPROCESS_QUEUE, eta_now=True)
   logs.info(f'Scheduled {len(fuzz_tasks)} fuzz tasks.')
 
   end = time.time()
@@ -222,11 +217,5 @@ def schedule_fuzz_tasks() -> bool:
   return True
 
 
-def bulk_add(queue_and_tasks):
-  queue, task_list = queue_and_tasks
-  logs.info(f'Adding {task_list} to {queue}.')
-  tasks.bulk_add_tasks(task_list, queue=queue, eta_now=True)
-
-
 def main():
   return schedule_fuzz_tasks()

src/clusterfuzz/_internal/system/environment.py

@@ -1177,3 +1177,7 @@ def can_testcase_run_on_platform(testcase_platform_id, current_platform_id):
                                                      current_platform_id)
 
   return False
+
+
+def is_tworker():
+  return get_value('TWORKER', False)