add support for running bugbug-selected tasks for autoland-based reviewbot pushes

bot/code_review_bot/config.py

@@ -67,6 +67,12 @@ def __init__(self):
         # Indexed by their Phabricator ID
         self.user_blacklist = {}
 
+        # bugbug test configuration
+        self.bugbug_enabled_repositories = ["firefox-autoland"]
+        # Because it's unclear how much load this will add, this is being rolled out gradually.
+        self.bugbug_enabled_percent = 0.1
+        self.bugbug_optimize_strategy = "gecko_taskgraph.optimize:tryselect.bugbug_reduced_manifests_config_selection_medium"
+
         # Always cleanup at the end of the execution
         atexit.register(self.cleanup)
         # caching the versions of the app

bot/code_review_bot/vcs.py

@@ -4,12 +4,14 @@
 
 import json
 import os
+import random
 import time
 
 import rs_parsepatch
 import structlog
 from libmozdata.phabricator import PhabricatorPatch
 
+from code_review_bot.config import settings
 from code_review_bot.sources.phabricator import PhabricatorBuild
 
 logger = structlog.get_logger(__name__)
@@ -22,6 +24,13 @@
 PUSH_RETRY_EXPONENTIAL_DELAY = 6
 
 
+def bugbug_enabled(repository_name):
+    if repository_name not in settings.bugbug_enabled_repositories:
+        return False
+
+    return random.random() < settings.bugbug_enabled_percent
+
+
 class RetryNeeded(Exception):
     """
     Raised when retrying a build is needed
@@ -176,6 +185,13 @@ def add_try_commit(self, build):
                 "phabricator_diff": build.target_phid,
             },
         }
+
+        if bugbug_enabled(self.name):
+            config["parameters"]["test_manifest_loader"] = "bugbug"
+            config["parameters"]["optimize_strategies"] = (
+                settings.bugbug_optimize_strategy
+            )
+
         diff_phid = build.stack[-1].phid
 
         if build.revision_url:

bot/tests/test_mercurial.py

@@ -7,11 +7,13 @@
 from unittest.mock import MagicMock
 
 import hglib
+import pytest
 import responses
 from conftest import MockBuild
 from libmozdata.phabricator import PhabricatorPatch
 
 from code_review_bot import mercurial
+from code_review_bot.config import settings
 
 
 class STDOutputMock:
@@ -73,11 +75,20 @@ def test_robustcheckout(monkeypatch):
     ]
 
 
-def test_push_to_try(PhabricatorMock, mock_mc, responses):
+@pytest.mark.parametrize("bugbug", [False, True], ids=["bugbug-off", "bugbug-on"])
+def test_push_to_try(PhabricatorMock, mock_mc, responses, monkeypatch, bugbug):
     """
     Run mercurial worker on a single diff
     with a push to try server
+
+    The bugbug parameters only affect try_task_config.json: the commits
+    themselves are identical whether the repository is selected or not
     """
+    if bugbug:
+        monkeypatch.setattr(settings, "bugbug_enabled_repositories", [mock_mc.name])
+        monkeypatch.setattr(settings, "bugbug_enabled_percent", 1)
+        monkeypatch.setattr(settings, "bugbug_optimize_strategy", "test:strategy")
+
     # Preload the build
     diff = {
         "phid": "PHID-DIFF-test123",
@@ -128,14 +139,18 @@ def test_push_to_try(PhabricatorMock, mock_mc, responses):
     assert open(target).read() == "First Line\nSecond Line\n"
 
     # Check the try_task_config file
+    expected_parameters = {
+        "target_tasks_method": "codereview",
+        "optimize_target_tasks": True,
+        "phabricator_diff": "PHID-HMBT-deadbeef",
+    }
+    if bugbug:
+        expected_parameters["test_manifest_loader"] = "bugbug"
+        expected_parameters["optimize_strategies"] = "test:strategy"
     assert os.path.exists(config)
     assert json.load(open(config)) == {
         "version": 2,
-        "parameters": {
-            "target_tasks_method": "codereview",
-            "optimize_target_tasks": True,
-            "phabricator_diff": "PHID-HMBT-deadbeef",
-        },
+        "parameters": expected_parameters,
     }
 
     # Get tip commit in repo

bot/tests/test_vcs.py

@@ -0,0 +1,39 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+from code_review_bot import vcs
+from code_review_bot.config import settings
+
+
+def test_bugbug_default_configuration():
+    """
+    The shipped rollout configuration is usable: a percentage expressed as a
+    ratio, a non empty allow list and a non empty optimize strategy
+    """
+    assert 0 <= settings.bugbug_enabled_percent <= 1
+    assert settings.bugbug_enabled_repositories
+    assert settings.bugbug_optimize_strategy
+
+
+def test_bugbug_disabled_for_unlisted_repository(monkeypatch):
+    """
+    Repositories outside of the allow list are never selected, even when the
+    rollout percentage is at its maximum
+    """
+    monkeypatch.setattr(settings, "bugbug_enabled_percent", 1)
+
+    assert vcs.bugbug_enabled("mozilla-central") is False
+    assert vcs.bugbug_enabled("nss") is False
+
+
+def test_bugbug_enabled_for_listed_repository(monkeypatch):
+    """
+    Repositories from the allow list are selected by the rollout percentage
+    """
+    monkeypatch.setattr(settings, "bugbug_enabled_repositories", ["autoland"])
+
+    monkeypatch.setattr(settings, "bugbug_enabled_percent", 1)
+    assert vcs.bugbug_enabled("autoland") is True
+
+    monkeypatch.setattr(settings, "bugbug_enabled_percent", 0)
+    assert vcs.bugbug_enabled("autoland") is False