Allow running experiments from PRs using GCB (#1637)

Fixes: #1599

.dockerignore

@@ -5,7 +5,6 @@
 .pytest_cache
 .pytype
 .venv
-__pycache__
+**__pycache__*
 docs
-report*
-third_party/oss-fuzz/build
+report*

experiment/run_experiment.py

@@ -282,11 +282,16 @@ def check_no_uncommitted_changes():
         raise ValidationError('Local uncommitted changes found, exiting.')
 
 
-def get_git_hash():
+def get_git_hash(allow_uncommitted_changes):
     """Return the git hash for the last commit in the local repo."""
-    output = subprocess.check_output(['git', 'rev-parse', 'HEAD'],
-                                     cwd=utils.ROOT_DIR)
-    return output.strip().decode('utf-8')
+    try:
+        output = subprocess.check_output(['git', 'rev-parse', 'HEAD'],
+                                         cwd=utils.ROOT_DIR)
+        return output.strip().decode('utf-8')
+    except subprocess.CalledProcessError as error:
+        if not allow_uncommitted_changes:
+            raise error
+        return ''
 
 
 def start_experiment(  # pylint: disable=too-many-arguments
@@ -315,7 +320,7 @@ def start_experiment(  # pylint: disable=too-many-arguments
     config['fuzzers'] = fuzzers
     config['benchmarks'] = benchmarks
     config['experiment'] = experiment_name
-    config['git_hash'] = get_git_hash()
+    config['git_hash'] = get_git_hash(allow_uncommitted_changes)
     config['no_seeds'] = no_seeds
     config['no_dictionaries'] = no_dictionaries
     config['oss_fuzz_corpus'] = oss_fuzz_corpus
@@ -597,7 +602,12 @@ def get_dispatcher(config: Dict) -> BaseDispatcher:
 
 
 def main():
-    """Run an experiment in the cloud."""
+    """Run an experiment."""
+    return run_experiment_main()
+
+
+def run_experiment_main(args=None):
+    """Run an experiment."""
     logs.initialize()
 
     parser = argparse.ArgumentParser(
@@ -687,7 +697,7 @@ def main():
         required=False,
         default=False,
         action='store_true')
-    args = parser.parse_args()
+    args = parser.parse_args(args)
     fuzzers = args.fuzzers or all_fuzzers
 
     concurrent_builds = args.concurrent_builds

service/Dockerfile

@@ -0,0 +1,32 @@
+# Copyright 2023 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/cloud-builders/gcloud
+
+RUN apt-get update && apt-get install python3-pip -y
+
+# Do this expensive step before the cache is destroyed.
+COPY ./requirements.txt /tmp/requirements.txt
+RUN pip install -r /tmp/requirements.txt
+RUN pip install PyGithub==1.51
+
+ENV FUZZBENCH_DIR /opt/fuzzbench
+COPY . $FUZZBENCH_DIR
+
+WORKDIR $FUZZBENCH_DIR
+ENV PYTHONPATH=$FUZZBENCH_DIR
+ENV FORCE_LOCAL=1
+ENTRYPOINT ["python3", "/opt/fuzzbench/service/gcbrun_experiment.py"]

service/gcbrun_experiment.py

@@ -0,0 +1,89 @@
+# Copyright 2023 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.
+#
+################################################################################
+"""Entrypoint for gcbrun into run_experiment. This script will get the command
+from the last PR comment containing "/gcbrun" and pass it to run_experiment.py
+which will run an experiment."""
+
+import logging
+import os
+import sys
+
+# pytype: disable=import-error
+import github  # pylint: disable=import-error
+
+from experiment import run_experiment
+
+TRIGGER_COMMAND = '/gcbrun'
+RUN_EXPERIMENT_COMMAND_STR = f'{TRIGGER_COMMAND} run_experiment.py '
+SKIP_COMMAND_STR = f'{TRIGGER_COMMAND} skip'
+
+
+def get_comments(pull_request_number):
+    """Returns comments on the GitHub Pull request referenced by
+  |pull_request_number|."""
+    github_obj = github.Github()
+    repo = github_obj.get_repo('google/fuzzbench')
+    pull = repo.get_pull(pull_request_number)
+    pull_comments = list(pull.get_comments())
+    issue = repo.get_issue(pull_request_number)
+    issue_comments = list(issue.get_comments())
+    # Github only returns comments if from the pull object when a pull request
+    # is open. If it is a draft, it will only return comments from the issue
+    # object.
+    return pull_comments + issue_comments
+
+
+def get_latest_gcbrun_command(comments):
+    """Gets the last /gcbrun comment from comments."""
+    for comment in reversed(comments):
+        # This seems to get comments on code too.
+        body = comment.body
+        if body.startswith(SKIP_COMMAND_STR):
+            return None
+        if not body.startswith(RUN_EXPERIMENT_COMMAND_STR):
+            continue
+        if len(body) == len(RUN_EXPERIMENT_COMMAND_STR):
+            return None
+        return body[len(RUN_EXPERIMENT_COMMAND_STR):].strip().split(' ')
+    return None
+
+
+def exec_command_from_github(pull_request_number):
+    """Executes the gcbrun command for run_experiment.py in the most recent
+  command on |pull_request_number|."""
+    comments = get_comments(pull_request_number)
+    print(comments)
+    command = get_latest_gcbrun_command(comments)
+    if command is None:
+        logging.info('Experiment not requested.')
+        return None
+    print(command)
+    logging.info('Command: %s.', command)
+    return run_experiment.run_experiment_main(command)
+
+
+def main():
+    """Entrypoint for GitHub CI into run_experiment.py"""
+    logging.basicConfig(level=logging.INFO)
+    pull_request_number = int(os.environ['PULL_REQUEST_NUMBER'])
+    result = exec_command_from_github(pull_request_number)
+    if result or result is None:
+        return 0
+    return 1
+
+
+if __name__ == '__main__':
+    sys.exit(main())

service/run_experiment_cloudbuild.yaml

@@ -0,0 +1,24 @@
+steps:
+- name: 'gcr.io/cloud-builders/docker'
+  args:
+    - build
+    - -t
+    - gcr.io/fuzzbench/experiment-runner
+    - --build-arg
+    - BUILDKIT_INLINE_CACHE=1
+    - --cache-from
+    - gcr.io/fuzzbench/experiment-runner
+    - -f
+    - service/Dockerfile
+    - .
+  env:
+    - 'DOCKER_BUILDKIT=1'
+- name: 'gcr.io/fuzzbench/experiment-runner'
+  args: []
+  env:
+    - 'PULL_REQUEST_NUMBER=${_PR_NUMBER}'
+    - 'POSTGRES_PASSWORD=${_POSTGRES_PASSWORD}'
+  timeout: 1800s # 30 minutes
+timeout: 1800s
+options:
+  logging: CLOUD_LOGGING_ONLY